Power Steering Basics and Stories

We Need the Power, Cap’n!


Some folks will drive vehicles for many a mile with inoperative power steering or brakes, and while the exercise they get that way builds muscle mass, it’s anything but safe, and parking maneuvers in a crowded lot are murderously difficult.  Once my extremely self-reliant aunt was driving an old Buick that had suddenly lost its power steering and she had angled across two parking spaces because it was the best she could do – and when an angry motorist shouted a question as to why she didn’t take three parking places while she was at it, my always dignified and unflappable aunt simply replied that the two parking places she had would do her just fine.


Which Way and How Much?


There was a time in my early career as an automotive professional that I believed I could fix anything, and in many cases, I was right. After all, we rebuilt power steering racks as a part of a recall when I worked at the Mazda dealer.  But the exuberance born of too many successes in coloring outside the lines can lead to a smack-down.

One hot summer day about 30 years ago I drew a work order on an early seventies Mustang with power steering trouble – and I don’t remember the original write-up, but I do remember making the discovery that a person without sufficient training shouldn’t tear a ball nut steering gear down to the bare parts and reassemble it expecting it to work right.

Just because I had successfully fixed the power steering systems on so many tractors and forklifts, I figured I could whip this one too. As it was, I got things so out of whack on the spool valve adjustment that whenever the engine was started, the steering wheel would whirl all the way to the right so hard that you couldn’t force it back to the center and for the life of me I couldn’t figure out how to fix that; I repeatedly tried to adjust the spool valve but it was no use.  After burning most of a day on that one, the decision was made to replace the steering gear with a used salvage yard unit and I had egg on my face.  In the years after that I replaced some pitman shaft seals and whatnot, but I never attempted a total steering gear rebuild again – after all, a replacement gear doesn’t cost all that much and the repair is finished a lot sooner.

On any kind of power assist, whether brakes, steering, or whatever, the control part of the system has to know when power assist is necessary, and in the case of steering, it needs to know which way that help needs to be directed. The same is true of electric power steering, and there is a very sensitive torque sensor built into the column on the hybrid vehicles Toyota makes, and it is that input that triggers the electric motor to muscle up.

On hydraulic rack and pinion systems, power steering pump sends fluid pressure to a spool valve that is connected to the steering wheel via the column; that spool valve is triggered by steering motion to direct the fluid. And there is sealed flange attached to the steering rack that travels inside a polished bore in the tubular steering gear housing. Each end of the steering rack is attached to a tie rod with a ball socket, the opposite end of each tie rod connected to the spindle arm so as to turn the wheels on their axes.  Fluid directed to one side or the other of the rack’s internal sealed flange provides the assist. Rubber accordion style boots on each end of the assembly protect the rack from dust and moisture, and the only thing that is supposed to be in those accordion boots is air, which, in many cases is transferred from boot to boot through a small tube.  Fluid dripping from these accordion boots on the end of the rack assembly means the rack is leaking internally and needs to be resealed or replaced, and some steering racks are extremely difficult to replace.  These boots obviously need to be replaced if somehow ruptured.


What to Do


Power Steering pumps produce between 1200 and 2000 pounds of pressure to do their work, and there is a specially designed flow control valve just inside the pressure outlet fitting.

When the power steering pump isn’t spinning fast, such as during parking maneuvers, not as much fluid flow is necessary, but high pressure is still required. Be that as it may, the flow control valve’s internal orifices and springs act to bypass some of the pump pressure internally so that the pump’s output pressure is slightly less than what the pump is producing, and it is this pressure that is delivered to the steering gear.

When the pump is spinning faster but with little or no steering activity (straight driving), fluid flow is increased, which reduces pressure at the pump outlet, and excess fluid is directed back to the pump inlet by the flow control valve. One way or another, the flow control valve’s springs and orifices are tuned to provide needed steering assist.

With the steering wheel held at full-lock and the assist chambers in the steering sector/gear are fully pressurized, the flow control valve acts as a bypass to prevent the pump from stalling out completely.  If the flow control valve malfunctions, you may see a quietly spinning pump that is full of fluid but producing no pressure at all. Obviously, replacing the pump is the most viable option – but I have on occasion replaced flow control valves when they were available. The problem is that in some cases they’re stuck in the bore and are too much trouble to remove. There is a test procedure using a pressure gauge to test the flow control valve, but it’s a pedantic test that’s too much trouble to fiddle with and we won’t waste time with it here.

Power steering lines have distinctly bent metal tubes where they connect to the steering pump and the gear and since the pump is on the engine and the gear is frame-mounted, the fluid travels through high pressure rubber hose en route for flexibility.  Some power steering lines have an o-ringed joint to handle the movement, and if you buy a cheap or cheaply built power steering line, expect that joint to fail almost immediately – that kind of failure happens more than it should these days, and it’s no laughing matter when power steering fails suddenly and the person driving the vehicle is low on muscle power.

When looking for a power steering leak, I like to start by having an assistant turn the wheels while I watch under the hood – if the pressure line is leaking, you’ll find it that way, and it’s wise to wear safety glasses.  Some power steering pressure line fittings are in tight spots where you might get a line wrench on them but have no room to move the wrench, and every technician needs a good set of crow foot line wrenches. Some pressure lines are long and convoluted so as to cool the fluid en route, and some of these convolutes have fins to help with the cooling.

I can’t write about power steering without telling about a power steering pressure line leak on a Lexus SC300 we repaired. When I called the Lexus dealership I rejected the $450 price tag of that power steering line out of hand.  Removing the pressure hose and sending it to the local parts store for re-rubbering turned out to be a disaster because the standard power steering line is 10mm and this Lexus line was 11mm, which bum-fuddled the parts guy, but it wasn’t hard to remedy.  I crocus-clothed the line down to a smooth round 10mm so the ferrules and nuts would work and we fixed that power steering line in short order.

The pulley on just about all power steering pumps requires a special puller, and a good one costs about sixty bucks, but you can buy a decent one for less than $20 on Amazon.com.  Due to variability in the field, some pulleys require more effort than others to remove– it’s a press fit, and they’re all tough, so always put plenty of grease the threads on the pump pulley puller threads or it may weld itself together – I’ve seen it happen more than once, and when that jackscrew stops turning on dry threads you have one piece of metal that used to be two.

Many of today’s pulleys are made of plastic but with metal hubs, and if you buy a cheap aftermarket pulley, recognize the fact that the pulley’s hub might be a bit too small to fit the shaft – this has happened more than a few times and brings the repair to a screeching halt. And on a plastic pulley, putting it in the oven for expansion is a no-go.  The pump shaft itself has threads tapped in the hollow end of it for pulling the pulley back on (the pulley tool has adapters that screw into those threads), but sometimes the threads are filled with rust or stuffed with dirt by dobbers and will need to be chased with an appropriate thread tap. The best pulley tools will have a thrust bearing that makes things go easier, and once again, grease the threads.

Remotely mounted power steering reservoirs are more or less the order of the day, and there is a screen in the bottom of the reservoir that likes to clog, confusing owners who find the reservoir full on vehicles where the steering is whining and hard. This plays out two ways – either the pump will be replaced without the reservoir screen being cleaned, or the pump will be destroyed from fluid starvation because the customer puts off getting repairs for too long. Always check the screen on one of these before replacing the pump, but realize that the pump probably needs to be replaced anyway if the whining has gone on for too long.

As for noise, don’t be fooled by those odd belts that look like sort of like gatorback belts but are shiny on their traction surfaces when they’re new. They can cause a nasty whine that can cause a technician to replace multiple components including the power steering pump. I’ve seen it happen again and again, and while the manufacturer of those belts seems to have stopped making them, you may see one in your service bay. Hear a whine?  Look at the belt.

I don’t like nasty fluid in any system, and this is GM’s way of flushing the system:

With the front end off the ground and properly supported, remove the return line, cap the nipple to prevent leakage, and point the hose at a container, then turn the wheel back and forth (engine off) while adding fluid until the fluid comes out clear. It may take a gallon of fluid, but you’ll get there.

Bleeding the system the right way is similar, but with all the hoses connected. Front end off the ground with the engine off, either spinning the engine (without starting) or not, you turn the wheels back and forth from 12 to 20 times from stop to stop depending on the length of the lines and whatnot. Hydroboost systems take more turns.  Start it, see if it whines, and if it does, repeat the process.


A Special Case


Another story I have to tell is the one about a 2006 Impala that bounced through a couple of shops (including a local GM dealership) for a whining noise in the power steering.  Neither shop apparently paid any attention to GM TSB (08-02-32-004B), which outlines a vacuum bleeding procedure with a $60 special adapter and a hand vacuum pump.  Well, we fabricated the bleeding tool with a piece of clear hose, a barbed brass connector, and a new rubber oil filler cap. Using the vacuum chamber that comes with hand held vacuum pumps, we installed the home-made rubber bleed cap on the Impala’s reservoir and connected the hose to engine vacuum with the hand vacuum pump’s isolation chamber in line, an arrangement that beats the stew out of pumping vacuum by hand.  After a minute or two of turning the wheels with the engine running, we had taken care of the whining problem without replacing the power steering pump.  R.W.M.

Electronics Can Be Crazy

Those of us who have been in or around the automotive repair business since the late ’60s can remember when the most complicated electrically driven parts in most American vehicles were the radios, the motor-driven windows or the turn signals. Then came Neil Armstrong’s problem with the Eagle. I read that he had to take the controls and do a stick landing on the lunar surface because the on-board computer malfunctioned. Whether that’s true or not, NASA decided to pour research into making computers smaller and more powerful.

They succeeded, and our lives (and our cars) would never be the same. Having grown up with the automotive industry, I’ve watched my little part of it change at warp speed.’


Most technicians were either intrigued or annoyed when those mysterious boxes started showing up under hoods, package trays and instrument panels.

These strange components were drawn into our schematics simply as outlined boxes blanketed with the words “Solid State,” as if the innards of those little critters were either too complicated for us to understand or so secret that we didn’t need to know how they worked.

The problem was that we needed to understand how these devices worked in order to properly diagnose customers’ concerns. For years now, the only real way to determine if one of these black boxes is bad is to analyze the inputs and outputs as best we can according to the literature available, and then plug in a new one or preferably a “known-good unit,” as the manuals so often say in their pinpoint tests.



Without covering all the ground between the lunar landing and vehicle body computers, let’s have a quick look at a few problems that I’ve seen.

The first case is a situation I experienced with a Mustang Remote Keyless Entry (RKE) system. Earlier Ford RKE systems had a stand-alone module, but on the ’99 Mustang, it had migrated to the innards of the Generic Electronic Module (GEM) module.

The transmitter fob on your keychain sends a radio signal to the GEM, which either locks or unlocks the doors, honks the horn if you so desire, while at the same time operating the door locks and activating the illuminated entry system. On this vehicle, the RKE system was totally inoperative. In many cases, simply reprogramming the GEM to recognize the signal from the fob takes care of the problem.

On that Mustang, cycling the key eight times puts the GEM in programming mode; the locks cycle to indicate it has entered the mode. When any button on the transmitter is pressed, the GEM cycles the locks in response to indicate that it has recognized and recorded the frequency of that particular fob.

When the key is switched off, the locks cycle again, terminating the programming session. As many as four fobs can be programmed in a session.

This Mustang entered programming mode and cycled the locks for me, but when I tried the transmitter after exiting the programming session, it still wouldn’t work.

To make a long story short, a ‘Special Service Message’ search and a subsequent call to the hotline revealed that I needed to go beyond regular service procedures. On early ’99 Mustangs, the hotline guy indicated, fuse 38 must be removed for a few seconds.

Reinstalling the fuse would bring the GEM’s RKE function back on line. It did.
My question was: “How was I supposed to know that if it’s not written down somewhere?”


I replaced the PCM on a 1997 Grand Cherokee and was satisfied that I had repaired a driveability complaint.

The next morning, the owner came wheeling back with the concern that her Vehicle Theft Security System (VTSS) was inoperative.

I plugged in the DRB III scan tool to make sure the VTSS was enabled, but it just wouldn’t work. By the way, don’t do this on a vehicle that isn’t equipped with VTSS, or you’ll have a nasty no-start that can’t be undone without replacing the PCM.

Usually, locking the doors with the RKE transmitter fob arms the security system on these vehicles and triggers a flashing indicator light, but this one was as dead as a hammer.

After 30 minutes of struggle, I decided to call the hotline. None of the hotline guys had a clue what the problem might be.

They forwarded my call to a higher level, where I spoke with a clever and articulate young woman who asked me how many times the Jeep had been started since the PCM was replaced.

I navigated the DRB III to the screen that gives that information and told her it had been started eight times.

“When the PCM has seen 20 starts, the VTSS will be activated.”

It sounded like a rather interesting prophecy, but after I started the Jeep 12 more times, the VTSS responded quite nicely in response to the fob.

While this problem would eventually have evaporated on its own, I had burned almost an hour of valuable shop time, and once again,my question was: “How was I supposed to know that if it’s not written down somewhere?”



Frequently updated scan tools can add a new element to a stressful, computer saturated service bay. The DRB III scan tool is a case in point.

I had just updated the DRB III via the Mopar Diagnostic System, and I was fighting another computer problem related to VTSS activation. I replaced the body computer on a Jeep Grand Cherokee with a false alarm activation; it was fooling itself into thinking the tailgate was open when it wasn’t.

I noticed that, once again, replacing an on-board computer had killed the Theft Alarm system. I couldn’t for the life of me figure out how to activate it on the new body computer. When I went to the appropriate screen on the tool, the menu just didn’t contain ‘Enable VTSS’ any more. The latest update had removed it.

It took three calls to the hotline before I found someone knowledgeable enough to tell me that I could boot up the tool on the memory card that was designed for older model years. Then, I could go to the same screen and the ‘Enable VTSS’ would be there. It was. Once again,my question was: “How was I supposed to know that if it’s not written down?”


I drew a repair order for a flashing high-beam indicator on a 1999 Grand Cherokee. Sure enough, it was flashing, but what I was seeing was a flashout of what looked like some sort of computer-generated binary code.

As I researched the circuit, I found that instead of the high-beam indicator drawing power from the wire leading to the high-beam headlamp bulbs, as in the old days, it was now taking its orders from the body computer. The computer received a signal from the dimmer switch on the column. The body computer commands the lights to switch from bright to dim, concurrently sending a command to the instrument cluster computer, telling it to turn the high-beam indicator on.

Why all this is necessary is beyond understanding. The hotline said to replace the instrument cluster (which was $480), but the problem actually turned out to be in the body computer.Who knows if anybody will ever see that again, but it was a costly lesson.


Sometimes even the simplest electronics can be aggravatingly devious.

The next case is a 1994 Mazda B3000 I encountered at the Ford dealer.With the radio on and the wipers operating on intermittent, the radio would wink off each time the wiper motor swept the blades to the park position. Power and ground feeds to the radio terminals showed no loss of power and no spikes on the oscilloscope. The radio didn’t respond this way to the operation of any other accessory.

We searched and actually found a loose ground at the wiper motor, repaired it and thought for a few minutes that the problem was solved.

Raising the wiper arms off the windshield appeared to make a bit of a difference, but the problem still occurred with clock-like regularity. Plugging in a new wiper motor and letting it run while holding it in my hand made no difference either. Finally we made a trip to the boneyard and robbed a radio out of an abandoned Contour.

When we plugged it in, the problem was gone.

Like so many other electronics problems, the only way to be sure is to try a known-good unit. And if we can’t find a substitute for the component in the boneyard, do we go to the trouble of replacing the radio in hopes that it’ll take care of the problem?

How are we supposed to know for sure? It’s tough to explain this sort of thing to some customers who think all we do is tighten screws and replace fuses.


Donnie drew the repair order for the 1998 Dodge Durango, and it was weird from the start. The “4WD Service” light was on and the vehicle was two-wheel drive.Well, he found a strange Chrysler TSB (08-032-00) which said to replace the HEVAC module – which is what Chrysler calls the control panel for vehicle heating and air conditioning – on two-wheel drive Durango units that exhibited this concern.

He ordered the $265 module, installed it and found that the “4WD Service” light didn’t go out. A call to the hotline revealed that the battery cable should be disconnected for 30 minutes, then reconnected and the HEVAC module should be configured with the DRB III.

During the configuration procedure, Donnie went through what

Chrysler terms a “cool-down test,” which brought the compressor online.

He also enabled the ambient air temperature display function while walking his way through the procedure.
He still had a flashing indicator on the HEVAC that wouldn’t go away.

Another call was made to the hotline, and the guy asked if he had enabled ambient air temperature.

“Yes,” said Donny

“Do you have an overhead console?” asked the hotline tech.


“Then you’ll need to order another HEVAC unit.”

“What? Why?” asked Donny.

“Because once the ambient air temperature display has been enabled, you can’t reverse the setting.” Donnie had the same question we have been asking for years now: “How was I supposed to know this? There’s nothing in the book that I could find about it.”

“You learn it by making mistakes.”

“Let me get this straight: When we replace a HEVAC module for the first time, the procedure is ‘Burn, Rurn and Learn,’ is that right?

“That’s about it.”


Made Them Look….

Once back in 1980 when I was living in Port Arthur, Texas, I was planning a trip back to Alabama, and so I went by the bank to get some cash.

I noticed that, at the end of the long line of tellers in Allied Merchants Bank there was a brand new ATM machine, so if you wanted to you could use the machine instead of a live teller.

Well, I had an ATM card, so I sauntered up to the machine, and it was like some kind of trigger that people started lining up behind me, most all of them businessmen in suits and carrying briefcases. Since I was on the way home from work, I was dressed in a greasy mechanic’s uniform.

I put my card in the slot and entered my pin, selected the prompt for withdrawing cash, and entered $350. The machines in those days were kind of slow and clunky and didn’t do things quickly.

After some hums and clicks the machine started kicking out twenties at the rate of about one every two or three seconds – at that rate (17 twenties and a ten), it was going to take about a minute and a half to give me all the money I had asked for.

As I watched the machine piling up that stack of bills, I noticed the businessman or lawyer or whatever the suit was behind me rubbernecking around me to watch my cash being dispensed…. and I took the cue, turned my head to catch the eyes of those in line, and said, loud enough for everybody in line behind me to hear,

“I think this thing has malfunctioned and is giving me ‘way too much money!’

I’ve never seen so many otherwise dignified briefcase toters get so wide-eyed and rubber-necky – it must have seemed like a dream come true, at least to some of them.

When the machine was done and gave me back my card, they all watched me walk away with a big smile on my face carrying my stack of cash.

It didn’t give me too much, but I had seriously “made those guys look” – in a big way.

All the Facts, Ma’am!

The facts, please, all the facts, even the ones that might not seem significant.


1998 Dodge Grand Caravan

179,598 miles

3.3L Engine

41TE Transaxle

“My van is ‘jankin’ when I drive.  I didn’t think I would make it here.”



Poorly Written Work Orders


Poorly written work orders can cause even the most competent technician a lot of headaches.  Some work orders are easy to write:  “Change Oil & Filter” or “Rotate Tires” is fairly straightforward. “Service Transmission” or “Tune Up and Replace Fuel Filter” should  lead to further questions on the part of the service advisor AND the technician.  But what about those times when customers are coming so hard and so fast that accuracy of information is sacrificed on the altar of hasty expediency?  There are questionnaires that customers are supposed to fill out for intermittent concerns, but they don’t cotton to that very much, and the service advisor may or may not use those sheets as a guideline when he or she asks the questions.

One service writer at the Ford/Jeep dealer where I worked hammered out a repair line that said

“Windshield won’t separate rain from water.”  Who on earth knows what that means?  I drew a work order on an Econoline van with several repair lines, the first of which read this way:

“Unit won’t start without left turn signal on.”

It was such an interesting problem that I fought it for about thirty minutes before I found that the wiring had been deliberately modified to work that way.  When I asked the service advisor about it, he said he the customer had informed him of the modification – (it was supposed to be a theft deterrent) and that he had added that comment so I would know how to start the van.  The Oxford Dictionary word “DOH!” came to mind. Thanks a lot for putting it on an R.O. repair line!

A third writeup dealt with an ABS brake warning light problem, and the customer described it very well, but the information he gave wasn’t passed along to the wrench man. The result was that the master cylinder was replaced because of a trouble code that pointed to the fluid level switch (which was fairly common on those Rangers), and the ABS warning light went away, but the exasperated customer had to return with the same concern to explain that the ABS light only popped on right after the parking brake was applied. I drew the job on its second visit, and with the customer’s diligent explanation of the concern, it became evident that there had been an information disconnect between what he had told the service advisor and the simple “ABS light comes on” writeup. In this case, the technician never applied the park brake, so he assumed he had repaired the concern when he replaced the master cylinder.

Gathering enough pertinent information from a customer is an art that a service advisor has to develop (some never do), and even when the customer knows enough to give a good description of the problem, communication of those thoughts on a work order can be pretty tough.  But what about those times when the customer sees something else going on that they don’t consider significant enough to mention for whatever reason?

The Familiar Bite


All she told me was that her Caravan was “jankin,” and I recognized that as a hybrid word that lands somewhere between “jerk” and “yank.”

I sent one of my more seasoned students with the owner on a test drive.  The student came back and described a surge, but said it only did it a couple of times just briefly.  The code we pulled was for an inactive or slow O2 sensor, which on a Chrysler can happen anywhere within the O2 sensor’s range, and too often it happens just above .5 volts.  With an active feedback fuel system in closed loop trying to correct that bad reading, a Chrysler product can do all sorts of bucking and jerking (the short fuel trim graph looks like large saw teeth, with corresponding engine response), and the code seemed to fit. I had seen this concern dozens of times when I worked at the dealer.

A second test drive with another seasoned student accompanied by the Nemisys scan tool showed a flatlining O2 sensor right at or above the .5 volt line just like we figured, along with those repeated fuel trim corrections that cause the engine to buck and surge.

In extreme cases such as on one particular 1991 Dodge pickup I saw, this syndrome can cause the vehicle to become practically undriveable without a re-start, and as soon as the PCM closes the O2 feedback loop, the problem returns.  The O2 can do this intermittently on Chrysler vehicles over a broad MY window that spans OBD I and OBD II years.

We had verified her concern and isolated a problem that fit her description of the concern.  We had probable cause, not only based on what our scan tool was showing us in the PID window but also on experiences I remembered with similar platforms – in a word, we had solid data and prior experience on our side. We had gathered our data scientifically and had seen no other concerns, related, or otherwise.  The Caravan would need an O2 sensor (this one only has one upstream sensor, by the way).  Game, set and match, right?

The price tag for that repair was $80, give or take a few bucks, since we don’t charge labor at the school.  She gave the thumbs up, paid the cashier ahead of time (don’t say it, guys I know that was a bad idea) and then she hopped on the college bus for an afternoon/evening field trip to ride a riverboat with some other students in Montgomery.  If all was right in the world, she’d be back at eleven that night to dig her keys out from under the seat and drive twenty miles back home through rural Alabama.

“That’s Gonna Fix It, Right?”


Service advisors, being human, like to be the customer’s hero.  They love calling to tell a stressed out owner that the problem wasn’t as bad or as expensive as we originally thought it would be, and they may not get a lot of chances to make those calls.  Too often, they have to call the customer with more bad news, and they loathe that experience.

It doesn’t make any normal person happy to be the bearer of evil tidings.  With that syndrome nipping at their heels, service advisors (particularly the ones that haven’t callused their hands with a wrench, had undercar dirt or snow fall down their shirt or dodged high voltage sparks), want the technician to give them a bona fide guarantee that the part the technician plans to install will take care of all the customer’s concerns. The simple fact is that we just can’t give them that guarantee.  Can anybody say “Verify the Repair?”  Every service manual on the planet includes a test of that nature to determine whether there are other problems after the guilty item has been properly diagnosed and replaced.

On the Caravan, what we thought would be the final test drive, the battery light started blinking and the van started surging really REALLY bad.  The guys who were doing the work coasted back onto my service lot with a totally dead battery. It was 4:00 p.m. on a Friday. I scrambled to find the cell phone number of our college bus driver and got her on the phone to explain the circumstances.  She needn’t expect to hop off the bus a nearly midnight and find her van ready to drive home.  She was a little disappointed, but very sweet about the whole thing, and we resolved to find out what the heck was going on the following Monday.

I figured the brushes were shot in the generator.  On Monday, we did a teardown and found that I was right.  When I called her, she told me that she didn’t have the money for a $200 rebuilt replacement. We deal with a lot of students that don’t have much money, so I wasn’t surprised.

We took some slightly better brushes out of another old Nippondenso generator we had on the trainer part shelf and patched hers.  The patch brought her generator back to life, but for how long?  The rotor slip rings looked horrible.

In these situations, I like to re-wind and ask a few questions in an attempt to determine what we could have done to avoid this land mine.

Question  1.  Why didn’t she mention the battery light, and/or dead battery problems if this was the same problem?  She had ridden on the first test drive and verified the surge.

Question  2.  Is it possible that maybe she hadn’t seen a battery light? Maybe it was a coincidental failure? Was this truly an information disconnect, or just a circumstantial land mine?

Question  3.  What do you do when you’ve spent most of what somebody had in their checking account on a repair that you were sure was totally legit only to find that the customer has another more expensive problem that rears its ugly head before the car even leaves the shop?

In the grand scheme of things, this pretty young lady was a lot better off with the car having quit on my two guys than she would have been if it had stranded her on a lonely country road somewhere at midnight.  Legal issues aside, none of us wants anything like that to happen to any of our customers.  Not ever.            R.W.M.

Heavy Mettle

Heavy Mettle Techs Needed

Richard McCuistian

Defining a problem is the first step toward solving the problem, but before any problem can be defined as a problem, it has to be recognized as such.  In our industry, there is a lot of talk about problems we’re facing, not the least of which would be issues like parts availability and pricing, customer satisfaction, keeping good people, service upsales incentives, the rising cost of doing business and so on.

As an automotive instructor, I feel I am making a contribution (however small it may be on a national scale) to the training issue, but what I’m hearing from the so many of the shops that call me isn’t so much that their employees lack training, as much of a problem as that is nowadays.

A primary concern in these parts is that a growing number of the more capable techs out there just aren’t too hip on showing up to work every day, and when customers so heavily depend on getting their vehicles back in a timely fashion, the unpredictable lassitude of some employees can be maddening.  Since I schedule so much live work in my automotive department, I run into the same problems when my automotive trainees don’t show.  I try to push the work through like regular shops do, else my grads won’t make the grade in the real world.

When I was in the field, I worked with more than a few of those guys myself.  I knew one guy who NEVER came to work on Thursday, and why the service manager put up with that nonsense as long as he did never ceased to amaze me.  The fact was that the guy could turn enough hours in four days to satisfy his need for a decent paycheck, so he always took a day off right before payday.

I have one very capable graduate who shows up at the service department about 6:20 a.m. (the shop opens at 7:30), works through lunch without complaining whenever it’s necessary, and stays late to finish important jobs.  The end of that story is that his employer wouldn’t trade him for anybody else.

So where is this “I got better things to do than go to work today” problem coming from?  It isn’t isolated to the automotive repair industry!

The problem is complicated, but for one example, there more than a few employers such as building contractors, farmers, and meat packers hiring the people some legislators call “undocumented” who come from south of the border.


One reason is because too many young American adults simply can’t be counted on to show up for work every day and in most cases, the foreigners can.  Don’t get me wrong: There are still a lot of responsible young Americans out there, but they’re getting harder to find, because they’re part of the same work force that contains another lot who have the idea that they should be able to set their own hours and take a couple of days off every week no matter what they agreed to when they filled out their application, passed their drug test, and unloaded their toolbox.

Granted, there are elements of most jobs that require some pretty serious skill, but there are many other needful things that simply require a strong back and a willingness to use it every day.  These are typically jobs that used to be filled by high schoolers in search of a summer paycheck.  I was one of those guys some 40+ years ago, by the way. One way or another, the employee that can be counted on to show up a few minutes before work, stay until closing and get every job done with a minimum of supervision is like money in the bank to a knowledgeable employer, regardless of what the job may be.

In our business, like any other, there are jobs for those with less skill, but that doesn’t mean those jobs aren’t profitable.  For example, we need people who can change oil, and that job, while it is extremely critical that it be done right, isn’t hard to learn, yet it is probably the most frequent piece of automotive service work done, and a busy oil change express establishment can take in from $3000 to $5000 a day, especially if the guy changing the oil is a well-trained upseller.

So what’s the answer to the quality labor problem?  There are probably a number of answers, but from my perspective as an instructor, doing what I can to endow my students with a good work ethic is at least as important as teaching them nuts and bolts, grease and steel, scanners and sensors, and how to chase sparks.

What does it mean to have a good work ethic?  My goal for the people I graduate is to make them “Heavy Mettle Techs,” because Mettle is what we need in America’s work force.

To begin with, a technician needs to show up every day on time, stay all day, and give the boss a day’s work for a day’s pay. If that sounds simplistic, it’s because it is. They need to be hungry for automotive knowledge and committed to the highest standards in excellence in every job they do, no matter how trivial it may seem at the time.  Every technician needs to be committed to the products he or she services as well as the employer, and finally, they need to take every service operation on every car as seriously as if their life depends on it, because in today’s world, it very well might!

That’s what it means to be a Heavy Mettle Tech.   And that’s what every shop needs.

Repair or Replace?

1998 F150

201,054 miles

4.6L Engine

4R70W Transaxle

Check engine skip – no MIL

Driving a vehicle and expecting things to go well is one thing, but when repairs are necessary, the customer calls the shots, but we have to guide them to make decisions that are right for them.  To begin with, we have to determine as nearly as possible what they expect to get out of an aging vehicle after the repairs are done.  Will they be making long trips or pulling heavy trailers or will they just be puttering it around town on the weekend?

First we have to find out what’s the problem is, and that’s where it all started on this F150.


Coming Back for More

When customers have a good experience at a shop, they generally return to that shop. This customer was no exception.  We have worked on her vehicles for awhile, and this particular truck was one we had replaced the wires and spark plugs on a few months back.  She came to ask if she could bring it to us and I gave her the green light.

When the truck arrived and the paperwork was done, it had a P0305 code and a dead skip, but no MIL at all.  Upon hearing this report from my guys, I sat in the seat and switched the ignition on to find that the MIL was inoperative. That dark and dead MIL would need fixing to be sure, but it wasn’t our primary concern.  Number five was a dead hole, but the injector was clicking, spark was present, and the spark plug didn’t look greasy. With the obvious out of the way, it was time put on our detective hats. When Webb and Kelley came into my office and put the known facts on the whiteboard, I put on my Horatio Caine “CSI Service Bay” sunglasses and said,

“Okay, this is what I want you to do.  Get a compression gauge screwed into that hole and let’s see how far that Number Five will push the needle. Spin the starter through for at least six puffs.”  As I heard them cranking the engine over, it was obvious to my practiced ear that the crank was picking up speed during one of the eight compression strokes, and I knew which one it was.  But the cause of the dead cylinder had to be further pinpointed, and we needed more data to complete our forensics.

After the six puffs the needle pointed to seventy pounds of compression. Their questioning glances said “What now?”  The next logical step was a no-brainer.

“Now,” I told them, “we find TDC compression stroke on that cylinder and do a cylinder leakage test.”

There are a number of ways to do this on a cylinder that has any compression at all and it’s especially easy when the cylinder in question is the number one hole or its companion, but what about the unmarked cylinders?

Since we have an IPA Tools® Calibration and Set Up kit (#7891), finding TDC is a snap on just about any cylinder.  First we screwed the IPA whistle adapter into the spark plug hole and the 70 psi of compression that piston was pushing was plenty enough to make the whistle tweet as the cylinder was coming up with valves closed. That got us on the right stroke, but we needed to TDC that piston else the air we were about to apply during the cylinder leakage test might blow it back down, driving the train to open a valve and invalidate our test.

To bring number five to exactly TDC, we applied the dandy spring-loaded IPA® TDC finder and brought the piston squarely to the top of its travel. With those tools put away, we did a cylinder leakage test and found just under 70% cylinder leakage – it should have been a lot less than that, and now we had two rock-solid bits of data – three if you count the DTC.  Now we needed to see where that leakage was going.

“Okay, guys, ordinarily we’d do some listening exercises with the air flowing through the leakage tester, but why don’t we apply smoke to that cylinder and see where it makes its exit?”

With the throttle propped wide and the smoke flowing through the leakage tester hose into the chamber, we saw smoke immediately came wafting out of the throttle body.  We obviously had an intake valve that was compromised for some reason, and I’d need to talk to the customer about this one.  If the intake valve had been totally open – 100 percent leakage – exploratory surgery might have been in order to check for a broken valve spring. As it was, this head would seem to be a candidate for a valve job, and that’s a pricey repair on a 200,000 mile 4.6L! Timing chain kits, gaskets and everything would put this repair estimate in the stratosphere.  A used engine might be in order if they weren’t planning on using the truck for another 20 years, and I called LKQ, who priced me a used one for $650.  I put left the F150 in a holding pattern and left a message for the owner to call me.

Dribbling Green


We had replaced the radiator and repaired the A/C in a 2003 Chrysler 300 at about the same time we did the plugs and wires on the troubled F150, and now the 300 had pushed its temp needle high again but for a different reason.  We also had a transmission swap under way on a 2002 PT Cruiser and would need to check that one for an overheating problem too, but that’d happen when we were through with the trans swap.  I had a couple of guys working on the PT, but I re-assigned the guy who was assisting with the Cruiser and had him tackle the 300, which, when we pressure tested it, turned out to have coolant leaking in a thin stream from behind the balancer.  This one would need a water pump and a timing belt.  Had this been a Sebring with a 2.7L in it, we would have shed tears, but this 300 isn’t that tough to deal with, and Garrett needed to do a timing chain and a water pump anyway.

Meanwhile, Braxton and Joe jerked a 98 Crown Vickie police package trainer vehicle into a service bay and began the process of removing the engine as a worksheet assignment.

We also troubleshot a 2007 Altima with a delayed reaction blower motor issue – she’d start the car and for five minutes the blower was inoperative, then it would come on line. We duplicated that concern quite easily, did some voltage checks at the fuses, and after we transposed the blower and defog relays, the problem went away. I ordered a replacement relay ($30) but it’s still lying on my desk – a delayed defogger just isn’t as noticeable as a windless fan. I’m still foggy about how a relay can cause that problem.

Speaking of fans, a guy came in with a Mustang that day because he wanted us to replace his cooling fan motor, which was fresh fried and stinking.  The reason for the fried fan was an distorted shroud, which had fouled the fan and kept it from turning until the windings were cooked. We had to explain that he needed every part of the fan, not just the motor, and more money would need to change hands to make that happen, but the bill wasn’t too bad. Back to the 300, since Garrett had to jerk the fan and radiator to access the timing cover properly, we decided to check the cooling fan motor for open commutator segments, because a bad fan can be famously intermittent, and it’s smart to do that.


The Dirty Hand is Dealt


The F150 owner called back and opted for the used LKQ powerplant, and the real adventure began.

Replacing the engine in a 1998 F-150 isn’t for the lazy, wimpy, or faint-hearted, and that’s why I gave the job to Willie, who is a Viet Nam veteran, older than I am, and tough as nails. Well, Willie got the engine installed, but not before we had to buy a $30.00 eight bolt flywheel from a local salvage yard because the original engine had a 6 hole crankshaft and the original flywheel wouldn’t fit. I had called LKQ and they verified that the vehicle in question could have either a 6 or an 8 bolt crank on a Romeo 4.6L, but it would be several days before he could get us the right flywheel, so we patronized the local salvage yard in the interest of time. What naiveté!

When the replacement engine was in place, we found it spinning with almost no compression along with intermittent backfiring through the intake. After checking and re-checking the spark plug wire routing, we measured the compression and found one cylinder with 99 psi and 40-60 psi on all the others. Adding oil to the cylinders did nothing to improve the compression, and while we didn’t do exploratory surgery, it was evident that the replacement engine had spun out of time for some reason – it was dead on arrival and Willie would need to change it out again.

Back on the Phone


I called LKQ and spoke to the sales guy about it; he asked for the vehicle mileage and installation date and had his warranty engineer call me on my cell phone. The call came in while I was at the grocery store late Friday afternoon, and his purpose was to establish the veracity of my claim that LKQ had indeed sold us a junk powerplant and to see if I was a buffoon who had jumped to the wrong conclusion. The guy was nice enough when I explained what we had done and how we had determined the engine was bad, and he wheedled a bit to try and get us to dig deeper to see what the problem with the engine actually was, but I dug in my heels.  This was a bad engine and we needed another one. It was as simple as that.  He agreed.

With iron resolve, Willie went right to work yanking the bad unit back out. The following Tuesday the LKQ truck delivered another 4.6L with 6,000 fewer miles on it, and the engine looked a lot cleaner overall. Oh yeah, it had an 8 bolt crankshaft like the first replacement too, so we’d be able to use our $30 flywheel.

Willie re-did the engine swap in a third of the time it took the first time around.

While that second engine swap was under way I wrote a ticket on a welding student’s 2003 Cadillac CTS that was blowing the right hand low beam headlight fuse – the headlamp assembly was awash with internal condensation and the owner had replaced an inoperative HID bulb on that side, which is no small feat since the bumper cover has to be removed for access. What we found was that that the HID bulb’s very expensive driver module had collected water. That module is mounted in the bottom of the lamp housing and tends to gather water that way. He put that repair off for a bit to explore other options.

While Willie was putting the finishing touches on the F150, a 100,000 mile 2007 Hyundai Tucson came wheeling in with a harsh shift – unless she feathered off the throttle at the point of the shift, the transmission would make a hair-raising slam shift from second to fourth, feeling like the Tucson had been rear ended by a Lincoln.

With my trusty MaxiDas online via the DLC, I analyzed the live data while she drove, and reasoned that the transaxle actually did shift right when she feathered the throttle, and pegged the problem as a software concern. I had her stop the vehicle and kill the engine, then switch the key on so I could reset the transmission adaptive tables. It was pretty amazing to both of us, but that fixed that problem. She was ecstatic, crowing about how she could spend the $1600 she had been saving for a transmission on something else.

And for a photoflash ending that made that a perfect day, Willie fired up the Ford and the second replacement engine was purring like a kitten when it left.  Mission accomplished!  R.W.M.

Two Among Many

“You have to keep the bead in the drop center part of the rim – it won’t stretch, so it has to able to move in on one side to clear the top of the rim on the other side.” On the first tire, I was there, pushing the tire down so the bead would be in the drop center, and that tire went on with no issues.
This guy seemed pretty sharp and seemed to be listening – but then he called me back to the tire machine when he was almost done with the second tire because he couldn’t get the tire on – it was almost on but it had stalled the tire machine because he had TOTALLY not kept the bead in the drop center – well, you know what that means – it’s tantamount to ruining the tire you’re trying to mount, and he had it to the point where we were almost past the point of no return.
“You deserve a prize for this,” I said (not loud, not angry, just.. you know, sort of tongue in cheek and with a chuckle), and I pulled the air piston around to push the tire down on the opposite side – managed to recover the situation and get the tire mounted.
Once again, this was the second tire of four – and he walked away and wouldn’t even try to mount the other two.
At the very least he should have stayed to watch so he could see how it was supposed to be done.
Not sure how that will play out in the real world.
There’s another guy I teach at another location – kind of small high school guy who seems somewhat timid – he’s always there – every day – and always does what I tell him to do… but occasionally, he’ll do something kind of dumb – not dangerous, just dumb. Those things that make your jaw drop, because you know he should have been savvy enough from prior work he has done NOT to make such a mistake. And in those situations, with that guy, I’ll say, with considerable emphasis and volume.
“What on earth were you thinking? You know better than this!!!”
He stands there giving me a blank look, and when we recover whatever went south, he picks up his tools and goes back to work.
Which one of these guys would you rather have as an intern?

Explorer Clutch Adventure

1997 Ford Explorer

89,058 miles

4.0L Pushrod Engine

Manual Trans

Clutch is difficult to operate; sometimes doesn’t release properly.

Horse Trading

The car was a 1965 Ford “Custom” a cheaper model of Ford’s Galaxie for that year. The fellow who owned it stopped by my dad’s VW shop one day said it used too much gas and he wanted to trade for a smaller car.  My dad had a ragged old VW bug for sale, and the fellow was so eager to get out of the Galaxie and into a gas miser that he offered my dad an even trade.  After the choke was adjusted on the Ford, the 289 (equipped with a column shift three speed, no air or power steering) actually got twenty-two miles to the gallon.  It was one of my first cars (as the oldest son of a shop owner, I had several) and I could drive it to the beach and back on an eighth of a tank of gas.

Those of us who pull wrenches for a living can be notorious horse-traders and when prompted, we can regale for hours those who will are interested (and those who aren’t) with story after story of engines, vehicles, and other such items we acquired for next to nothing and nursed back to health with wrench smarts, TLC and a few used parts we had in the shed or out behind the barn.  Behind every such trade lies a story that isn’t finished until the item in question passes from our hands.  As for the ’65 Ford, I probably remember it as a better car than it actually was, but sometimes I wish I had kept it.

Yet with all the stories we tell about our own good fortune, each of us knows those happy-go-lucky money-squeezing situations simply can’t and won’t work consistently in the day-to-day grind of fixing broken cars.  Digging an old part out of a pile of junk to get our own toys running is one thing; repairing cars for the public is something else entirely. It’s impossible to consistently produce the endless supply of cheap used parts it would take to get customers’ cars running on a shoestring budget.  And while salvaged powertrain components are widely used in our industry, most of us have lost dozens of labor hours as a result of installing a salvage yard part that we relabeled a “junkyard part” when we went to the trouble to install it only to find that somebody else had already used the good out of it.

Needles and Linings


Most of my students are on an extremely tight budget, and it’s not uncommon for one of them to have a ticket written on their own vehicle.  This  story was born when Steve (one of my students) decided to replace the slave cylinder in his 1997 Explorer.

This Explorer’s problem was that the clutch pedal required some heavy thigh power, and occasionally the transmission would clash while shifting into gear, particularly reverse.  I encouraged Steve to go deeper than the slave cylinder/throwout bearing assembly once he and his partner got the transmission out; the difficulty in shifting and the gear clash he was experiencing in reverse evidenced the fact that something was applying rotational force to the transmission input shaft when the clutch was depressed in spite of the fact that the clutch had full travel and no free play.  It started out to be a pretty straightforward job.  Push, pull click, click, and drive it home.

With the transmission out and the pressure plate removed we found a clutch disc whose useful life had slipped away; the lining was worn almost to the rivets.  The root of the undesirable input shaft rotation seemed to be tied to a disintegrating pilot bearing.

Aftermarket clutches come only in sets nowadays, at least in this part of the country, and the price of a matched set hovered near $200, a little rich for Steve’s wallet.  Fortunately, we were able to purchase a remanufactured clutch disc separately from the Ford dealer.  With the new slave cylinder cashing in at $55, the pilot bearing at $16, and the clutch disc at $60, Steve had a bit more than $125 invested, but not nearly as much as he would have with a parts house set.

I was fortunate enough to find an old Ford input shaft from a trainer transmission, and Steve used it as an alignment tool. In an hour or so, the transmission was back in place with a minimal amount of trouble.  Bleeding the new slave cylinder is a pretty involved process in the Ford shop manual, but it turned out to be a snap this time around.  The air burped out, the clutch pedal was nice and tight, and it didn’t require nearly as much of a meaty leg to operate the pedal.

But with the engine started, it became obvious that something was still rotating the input shaft, and the problem was slightly worse than before. As a matter of fact, the engine had to be shut off to get the transmission in reverse.  Steve decided to drive the Explorer for a few days until we could get it back on the rack and re-yank the transmission for another look.



Another Look

The second trip Steve and Big Country (his partner’s nickname) made into the bell housing revealed nothing out of the ordinary on our initial inspection; the pilot bearing was still intact and rotating freely, but I was interested in having a closer look at the new slave cylinder.  Steve removed it, and we stood it up next to the old unit for comparison and found that the old cylinder was about 3/8 inch taller.

Our line of reasoning was that the newer, shorter slave cylinder just didn’t have the travel that the original cylinder did, thus it wasn’t completely disengaging the clutch.  It made for good theory. To further undergird our hypothesis, we did some research and found that the original slave cylinder was an earlier model; indeed, the stamping number on the transmission was for a ’95 model; it was ostensibly two years older than the Explorer we were working on (unless the F5TZ number was used in the ’97 models), and Steve said he remembered the previous owner admitting that he had replaced the transmission.

Steve and Big Country installed the new slave cylinder, slid the transmission back in place, and found that the hydraulic line wouldn’t mate properly with the second new slave cylinder’s fitting.  This clutch hydraulic line snaps into the fitting using the same principle Ford fuel lines have employed since 1991, but the fitting is substantially larger than a fuel line hookup.  For removal, a plastic sleeve built onto the male fitting releases the fingers that hold the line into the female part of the fitting, and shop manual procedures call for a special forked tool to operate the plastic sleeve.

The line looked as if it should have snapped into the second new slave cylinder, but it would pop right back out each time we tried to snap it in.  How the previous installer had snapped the line into the original slave cylinder is beyond understanding, and fluid restriction due to the improper line hookup may have been the reason for the original hard pedal concern, especially since we didn’t replace the pressure plate.  From another transmission I was using for a trainer, I retrieved another slave cylinder like the shorter one we had rejected, and we could see right away that the fittings were indeed different.  Steve pulled the transmission back, removed the slave cylinder, and swapped the fittings to mate the line with the new cylinder.



Bleeding the Unbleedable

The first new slave cylinder had eagerly embraced fluid and spit out air like it actually wanted to be bled.  This second cylinder seemed to like air a lot better than fluid.  We couldn’t get it bled.  The pedal stayed mushy and uncooperative.  The Explorer stayed on the lift that weekend and Big Country gave Steve a ride home.

Monday morning, with the transmission removed once more, we found that Bi Country’s fitting swapping operation had been hastily done and that the fluid had been leaking at the point where the fitting feeds the slave cylinder.  With the o-ring seal properly in place and the transmission reinstalled, the slave cylinder bled out quite nicely, but the clutch still wouldn’t release.

Confused by circumstances into believing we had some sort of oddball mismatch between the ’95 model transmission and the ’97 Explorer, we reasoned that the clutch had worked properly with the longer slave cylinder in the first place, but that the clutch disc had been thinner.  We also reasoned that the shorter slave cylinder had worked better with the new clutch disc than the longer one did.

With that in mind, we decided to reinstall the shorter slave cylinder, but with a homemade steel shim installed between it and the bearing cover that would give it the necessary support, yet enable it to have more travel.  With the transmission back in place and the cylinder bled out, we had the best pedal we had ever felt when that silly modification was made, but the clutch still wouldn’t release, and the concern actually seemed to be getting worse.

This was getting ridiculous; replacing a clutch isn’t rocket science:  We were obviously missing something very basic.

One of the other students claimed he had fixed a problem like the one we were having by replacing the pressure plate.  I wasn’t convinced.  We took the clutch back out, removed the flywheel, installed the clutch disc and pressure plate on it, and mounted the whole assembly in the shop press with the dummy input shaft splined into the clutch and inserted in the pilot bearing. Utilizing an old locked up slave cylinder and a big socket, we depressed the diaphragm spring until we could rotate the clutch disc.  We marked the amount of travel required to release the clutch.  The fingers had to move a full ½ inch to release the clutch.

I picked up a Ford authorized remanufactured pressure plate from the dealer, and we performed the same press test, comparing the travel required to release the clutch.  The new pressure plate actually required more slightly travel than the old one.  So much for the pressure plate theory!



Taking another really close look at everything in the bell housing once more, I decided to slide the clutch disc on the transmission input shaft and spin it.  At first it seemed to be straight and true, but then the more I observed it from different angles, the more I realized the disc was slightly warped.  Fetching a dial indicator, I set it up to measure lateral runout and found a whopping 0.065 inch of runout that would scrub against the pressure plate and flywheel, effectively rotating the input shaft and sabotaging the release operation of an otherwise healthy clutch assembly.

Since a transmission jack was used and we never forced it through the clutch disc splines with long bolts or let the weight of it hang, we had to conclude that the remanufacturer had relined a warped disc without checking it for lateral runout.