noise."The F250: Insert White Whale Reference Here · 4:44pm Nov 19th, 2017
One of our customers has this giant, diesel, 4wd crew cab long box F250 Super Duty. It's like a 2003 or something, and it's got over 300,000 miles on it. It's also got just about every bolt on accessory that they make for those trucks. Now, I'm not talking about the silly stuff, like Pontiac's stick-on excitement from the 90s (probably most of y'all are too young to get that joke)--he's got the kind of things that are actually functional. Like a heavy-duty front bumper that is useful for when you want to chop down a tree by driving into it.
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Not the actual truck. The actual truck is more badass than this one.
He's not afraid to spend money to keep his truck up, fortunately. Some of our customers are super cheap . . . like, we had one guy who wanted us to hang his exhaust back up. "I've even got the parts," he said proudly, and held out a wire coat hanger.
We ran him off.
Back to the Super Duty. He brings it in to have all the fluids changed, and he also says that it's got a blown brake line.
Pretty straightforward, actually. It's the main feed line from the ABS pump to the rear axle, and it's not too hard to get to.
So we get the brake line replaced, change all the fluids, rotated the tires, and I think there was something else we did, I can't remember exactly. The guy was adamant that he wanted Royal Purple in everything (he wants the truck to last at least 400,000 miles), and he was perfectly willing to spend the money.
Anyway, by the time all's said and done, he's spent about $3,000, most of it on Royal Purple (if you have to ask what Royal Purple costs, you can't afford it).
He picks the truck up, and a couple of days later mentions that the brakes don't seem to be working right.
* * *
I've got to step aside here for a moment and explain how brakes work, because this will be important later. The foundation brake system consists of the brake pedal, which you push. That is transmitted to some kind of brake booster. Those are typically vacuum, although some applications--especially diesels--use Hydroboost, which uses the power steering pump for this purpose. [There are also weird systems on Hybrids, which we won't get into, and some older, obsolete vehicles which have manual brakes (I own three such vehicles)]. If you lose vacuum on a vacuum system, the brake pedal gets hard, but still feels like it works, whereas on the Hydroboost systems, if you lose power steering fluid pressure, the brake pedal becomes rock hard, and feels like you've got no brakes at all. Also, you normally don't have power steering, either.
That force is transmitted to the master cylinder, which then sends pressurized brake fluid to the ABS module, if the vehicle has ABS. For right now, we're going to ignore the ABS module, but we'll be getting back to it.
The brake fluid then goes to the wheels through a series of tubes (much like the Internet), and pushes on a piston (caliper or wheel cylinders), which push against the friction material, which pushes against a rotor or drum, and turns your forward momentum into heat.
There are a series of valves in the system. Due to weight distribution and brake designs, most vehicles have some sort of proportioning valve, which can delay brake application on one end of the vehicle, or reduce the pressure to one end of the system. It'll also have some sort of a pressure switch, which will illuminate the red brake warning light if there's a loss of brake pressure, and they typically also have some kind of valve that hopefully closes if you have a brake leak, preventing the loss of all your fluid, and allowing you to still stop. On some vehicles, that's all built into one little unit called the combination valve; on others, it's distributed around the brake system.
The ABS module prevents the wheels from locking up. On older vehicles, they can't apply the brakes, but they can release the brake on one wheel if it locks up, and then re-apply the pressure once the wheel is turning again. This is important for stability reasons. Incidentally, newer vehicles have ABS modules that can apply the brakes, even if you don't push on the brake pedal, and they use that for rollover protection, traction control, and other purposes.
Some of those valves I was talking about earlier are built into the ABS module.
* * *
I'd driven the truck once since the brakes were fixed, and I thought that something felt off with the Hydroboost . . . like, it was working, but not very well. There's some springs and valves and stuff in it, and I thought that maybe they were worn out. After all, the truck has over 300,000 miles on it. I didn't mention it, because I figured maybe he's used to this, or maybe the manager told him about it and he didn't want to fix it. Turns out I was wrong about that.
The owner of the truck had said that sometimes the brake pedal went to the floor. I drove it, and I didn't get it to do that, but I did notice that the brake assist felt weird, and sometimes when I was stopped and held my foot on the brake pedal, it would all of a sudden drop to the floor, and other times it would sort of kick back at you. I thought that that was probably caused by the Hydroboost.
My manager thought that it needed a master cylinder. He thought that maybe the loss of fluid had damaged one of the internal seals.
I thought he was wrong, even though to hear him tell it, he's always right. So I put a master cylinder on it, and drove it again.
The hydroboost still felt wonky, but the brakes didn't go to the floor, so we shipped it out.
A week later it was back.
If you were paying attention above, you'll have figured out that in a Hydroboost system, the power steering system and brake system are interlinked. This is important.
According to the manager, every twenty five stops or so, after using the brakes, the brake pedal would stay down at the floor and the truck wouldn't move until you pulled it back up.
That was a symptom I couldn't duplicate at all, even after driving it for nearly an hour and stopping a lot.
I did make some other observations, though. I noticed that at low speeds, you didn't have any power steering, and that if you held down the brakes, you'd also lose the power steering. I also noticed that sometimes when you were on the brakes, it would twitch the steering wheel one way or the other--usually right, but not always. If I wasn't paying attention and hit the brakes hard and it did this, the truck would start to swerve into oncoming traffic or the gigglyweeds . . . I didn't want to hit the brakes without having a good grip on the steering wheel.
So this time, it got the Hydroboost unit I thought it had needed all along, and a power steering pump as well, just for good measure. And all was well with the world.
Fifteen minutes after paying for the repair, the customer brought it back. The steering felt great--better than it had been in years, he said. But the brakes were still doing the same thing. He had me jump in and ride along with him, so he could show me.
Remember when the manager said that every 25 stops or so the brake pedal would stick to the floor? That's not at all what the customer told me and showed me. Rather, when he made a really hard stop, the brake pedal would come back up, but the brakes would stay applied for four seconds before releasing. And that was easy to duplicate--stomp on the brakes, it did it every single time. It was also fun--once I got the timing figured out, I could come up to a stop sign, stomp on the brakes, then let my foot off the pedal, and the truck would stop the rest of the way for me, then start going again.
For better or worse, I had all weekend to think about it, and I came up with nothing. The only thing I could think was that something was wrong with the new master cylinder, especially since he couldn't say if it had done that before the brake line leaked or not, but he didn't think that it had. While that wasn't all that helpful diagnostically, I'd rather have a customer tell me he isn't sure than lie.
So we got another new master cylinder on it, and I probably don't have to tell you that it fixed nothing.
At this point, the fight was on.
One other thing that my manager does that's stupid is that he's lazy. Not just for himself, but on our behalf, as well. While we'd done a brake line and a master cylinder and a Hydroboost unit, nobody had ever actually looked at the calipers and friction material. Apparently, he had told the other guy to not pull the wheels and look at the brakes.
Now I got to do that. And since my manager felt that the problem was the front brakes, I pulled off the front wheels and took apart the front brakes. I found that one of the caliper pins was sticking, and that the dust boots on the calipers were in terrible shape--the rubber had broken down completely, and they were about as effective at keeping dust and gunk out as a colander would be at carrying water.
The pistons did retract, though, and the pads moved on their slides, so I cleaned up the pins and lubed everything and took it for another drive.
No change.
So I put on new front brake calipers.
No change.
Then the manager said that maybe it was the rear brakes (which still hadn't even been looked at up to this point).
All four of the pins were stuck on the rear. For anyone keeping a tally, one was vice-grips stuck, two were air hammer stuck, and one was torch stuck.
I got them out, cleaned up the brackets and slides, replaced the pins, and put it all back together.
Of course, that didn't fix it.
So I put on new rear brake calipers.
Which also didn't fix it.
At this point, I'm pretty much out of ideas, and I'm really frustrated, because I've spent two days taking this thing apart and putting it back together, and it would have been so much easier to have actually checked the brakes the first time the truck was in. We would have found all those things, and we could have given him a price on them at the very beginning, but now the manager is in a kind of panic mode because he doesn't want to make this guy have to spend any more money than he already has.
The only thing left that we haven't replaced at this point is the ABS module, and even though I'm reasonably confident that it can't apply the brakes on its own, I pulled the fuse and took it for a test drive that way.
Source
Not the actual ABS module on this truck, but it's pretty similar.
Which fixed the problem.
To make sure that wasn't a fluke, I put the fuse back it, and the problem came back exactly as before. Fuse back out, problem's gone.
Of course, the manager had to drive it himself to verify, but this was in fact the issue.
It turns out (and I discovered this as well) that when you do a panic stop in this truck, odds are very high that you're going to lock the rear wheels. There isn't a lot of weight back there when the truck's empty. Also, I might have made some guy in a Tahoe crap his pants, because how I tested this thing was to go blasting down a back road at sixty and then pound on the brakes hard, and while I was nice enough to check the rearview mirror and make sure that there wasn't anybody behind me before I did this, I paid no attention to oncoming traffic. So the guy in the Tahoe saw a big white Ford the size of a small city bus blasting along towards him, and all of a sudden, the nose drops and the rear wheels lock up for no apparent reason, and I actually slid past him before I let my foot off the brake.
Looking back at it in hindsight, it's perfectly obvious what happened. Probably when it ran out of brake fluid in the rear, something in the ABS module got damaged by the lack of fluid--some seal, perhaps. Or else the gunk in the bottom of the master cylinder got washed into it, who knows? Once we fixed the fluid leak, the ABS module went back to doing what it was supposed to do, but when it was time to release that brake pressure, it took it about four seconds.
We put a used ABS module in it. I don't know if the manager gave the guy the option of new or used (I do know that ultimately, the ABS module wasn't on the final bill). That, luckily, went smoothly, and thus far, the truck hasn't come back.
There are several lessons to be learned here. One that the Think Like a Horse guy often says is that "the slow way is the fast way." If you take shortcuts, sooner or later they'll be back to bite you. We'd had the tires off when it was first in; it wouldn't have taken more than about fifteen minutes at the most to have discovered that the caliper pins ranged from bad to worse, and had that been discovered earlier, it would have saved about a day's worth of my time.
There's the lesson that sometimes vehicles fail in mysterious ways. Things you'd never think of, or even dismiss as impossible, and yet it happened. In almost 20 years as a mechanic, I've never seen an ABS module fail in that way, and I've been working on that style of F250 since the day they first came out.
There's the lesson in the scientific method. We have a hypothesis, and we try to conduct an experiment to either verify our hypothesis, or not. And sometimes that does turn into having to use what the service manuals call a 'known good part.' In the case of our F250, if I had five pressure transducers and adapters to put them inline in the brake system, I could have diagnosed the truck in minutes, but I don't have that equipment, so I had no choice but to eliminate things one at a time, from the most obvious to the least.
There's the lesson in getting your information right from the horse's mouth. This isn't the first time that a manger has told me the wrong symptoms, and it probably won't be the last. In fact, I know it won't, because it happened again this week, and it also involved brakes, and it also involved direct orders to half-ass a brake inspection
And I guess there's the lesson that sometimes a vehicle will kick you ass, not once, not twice, but it'll keep coming back until you reach the point where you're seriously considering if there's any way you can 'accidentally' set it on fire with the torches.
Finally, there's the mechanic's rule that you have to be ten percent smarter than whatever you're working on.
. . . Well played, F250. Well played.
Jeez, that's scary to read.
I used to think the incompetent manager was more a storytelling cliche than an actual thing that you might be likely to run into in the real world.
I love your tags.
If it makes you feel better I worked an all ages paint party last night and the client booked us short by 4 people... Kids left in ambulances because we didn't have the people to police the 3/4'rs ass barrier between 19+ and general admission. Hell from my post a good 20 feet away I saw 7 people with booze jump the barrier and I couldn't see all of it.
So at least your boss's cheapness didn't put 4 kids under 18 into the hospital.
Here is my question, how much could you get away with on occasion just ignoring your boss at points like this? He seems fairly incompetent at his job and relaying on you to keep the shop running. You could make a killing I bet at going into starting your own shop.
Yowza. And I thought accidentally sending meeting cancellation notices to the clients was the scariest thing that could happen while testing a problem fix.
Keep throwing parts at it until it's fixed, eh?
Sounds delightfully Ork-y.
On a semi-related note, I discovered rather recently a youtube channel that seems to be all about dismantling old engines, cleaning them, polishing them, and reassembling them... all presented in a neat timelapse. I can't remember the name of the channel, though, so now I need to look for the videos the hard way...
This was a journey.
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It goes both ways. The idea is probably over-used, but there really are lazy butts sprinkled liberally through the workforce, and sometimes they end up in charge. I know I've seen my fair share of people who should not be managers get to be because they're young, and the company hopes to mold them into competent go-getters.
And sometimes even that works out. I remember one manager trainee who, on their first day, gingerly tapped lids on paint cans, extending their arm waaaaaaaaaaay out so they'd be the maximum distance from any potential splatter. But by the time they got their own position, they'd adapted to using an apron, splatters be damned. I honestly was mystified that they grew to care so little about splatters. But anyways, they became a pretty good manager despite the incredibly timid beginnings.
I suppose it's all about whether someone can be taught. And the bad, lazy managers, are people who can't/refuse to be.
If that guy is getting so much work out of such a large vehicle, maybe he actually needs something more appropiate.
Like a UniMog.
myvan.com/wp-content/uploads/2017/02/unimog-twist-test-track.jpg
As for the mechanic having to be smarter than the car, I was brought up on ultra speed home computers and Knightrider in the 80s, 90s, and so demanded that the intelligence and capability of the computer increase as its processing ability increased, along with the simple fact, Everything Fails, especially the power.
Statically, for every wire connecting two componants there are 5 modes of failiure. Dynamically, well, just how many ways are there to inject power, data attacks into a system? Even as passive intermittent faults?
That was painful. I don't recall off-hand, but do you often come across unsolvable problems?
Reason I ask is that this scenario is very familiar. I work in VOIP telecom and sometimes we end up going through the same quality of hell trying to get problems resolved (sometimes internationally). And once in a while, it just works out that the customer has either lied, doesn't communicate critical information they have, or just doesn't know their equipment well enough to share the right info. In those extreme cases, we can pretty much prove that it isn't US. You want to help and resolve all issues, but at the same time you eventually have to draw the line and stop throwing resources at a problem that's out of your control.
I would pay for a book of your essays on Adventures in Automotive Engineering. In hardback. On launch. I'd go get it signed, too.
I KNOW THAT FEEL BRO. Ive had a couple of cars kicking my ass lately. Never had an abs pump do that either, you learn something new every day. But I tell you, hydroboost brakes always feel wonky. Every one Ive ever had, even the electric ones (old caravans), feels like the pedal wants to go to the floor. I hate it.
4730039 Oh thank goodness, I'm not the only one.
as you know i own a (1996 f250 7.3 diesel with low miles only 284k) my self witch is a total different type of braking system is it only has rear ABS.
but if you change the rear cylinders it will do the same crap. i have changed my ABS 10 years back and i am betting when i flush the hole system when i change the master cylinder i will be changing it agene.
my truck has the vacuum style booster so that is easier to deal with.
if you ever get stuck trying to find parts for the dana50 ifs give me a shout i have a good suppler that is out your way.
... wow. Just, wow.
That was a nightmare scenario that all non mechanics fear , I put 3000 dollars in this car and it stlll isn't right!?
oh it was just the 10 cent fuse
I think I've seen those guys in the truck ball bouncing video. That was a tough one to troubleshoot, especially with all the missteps. The important thing is that it's fixed and safe.
4730039
Me, too!
4729874
Yeah, it is. I basically have to ask him each time if we are going to pull off the wheels and get an actual good look at the brakes, if we're going to check drum brakes, etc.
4729878
Sadly, it's not.
And I suppose incompetent depends on who you ask. He's good at selling stuff and making customers happy, so in that respect, he's a good manager. He's just not good at keeping me happy.
4729880
If I'm going to put in hashtags, I might as well have fun with them.
That sounds awful.
It's actually a problem at CMH sometimes, too. When we're understaffed, we can have trouble keeping all of the guys out of trouble. Or have somebody wander off in the middle of the night, and you can't do anything about it, because you're the only person in the house, and you can't leave the other guys alone.
Also, what the heck is a paint party?
That's true. Although I do fear the day when a mistake or something we overlooked on a vehicle leads to a crash. So far that hasn't happened, but it's every mechanic's fear.
4729887
It's hit or miss, really. One of the problems is that he doesn't listen half the time. I do the best that I can and document everything on a work order, whether I'm supposed to or not. I wanted to talk to the owner about this kind of stuff, but he keeps blowing me off, so I stopped worrying about it.
Well, I am the one guy who fixes most of the cars.
I did get a bit of a laugh on Friday. He was taking a rubber exhaust hanger off a car and really struggling with it. I was holding the tool for those in my hand, one foot away, but he wanted to do it himself, so I let him struggle until he got it, then pointed out that I had the tool in my hands.
i'm not so good at doing sales, though. And it's a huge headache to own your own shop. I wouldn't want to.
Too bad I don't live near you, I could make YOU fix my transmission...
4729924
We've had a car backed through a garage door, another one crashed into the alignment rack (slowly, but it hit it just the same), and a few other problems. Not recently, luckily, but I've seen a few tech-started engine or floor fires, and a little over a year ago, I got first and second degree burns across my entire back thanks to a dumb Jeep.
Our former manager totaled a customer's car on a test drive. It wasn't his fault; somebody drove into him head-on while he was stopped at a stop sign, but still. . . .
4729928
That's not the best way to do it, but sometimes that's the only thing you can do.
I've seen some like that, although I don't remember the channel, either.
4730397
Pretty much exactly what it sounds like, go to a dance club, dance and enjoy the music and have paint sprayed over you.
Thankfully this one was super cheap and they used watered down water soluble paints, I've lost so many uniform shirts to other events that use the heavier shit.
4729935
I spent three days working on the brakes on that dumb truck. One of them was a day that I exclusively worked on the brakes on that truck (that was the clean the caliper and then replace the caliper day).
4729937
There was a guy I worked with at Firestone that was like that. He was going to school to be an automotive engineer (which was nice; we'd show him dumb designs on cars all the time), and was a kind of prissy guy when he started out. On his last day, before he left he went to shake everybody's hand. Mine was covered in oil, and I said I should wash it off first, and he said 'don't bother,' and shook my hand.
Pretty cool dude, overall.
Another guy I really respected came in the back his first day as a salesman and admitted that he didn't know anything, but that we mechanics could teach him, and as long as we told him what the car needed and why, he'd sell it. And he did, and by the time he left, he knew lots about cars.
4730006
There is a guy who stopped by once that was using an old army 6x6 as his daily driver over the summer.
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It's ground side failures that really get you, though. Usually, power side is easy to diagnose. Ground side is overlookd a lot, and can cause some really weird symptoms.
I can think of three--short to power, short to ground, and open. Not sure what the other two would be. Any of those three could be hard faults, or intermittent.
Well, I suppose loss of power or loss of ground, could be numbers 4 and 5, but we'd usually just call that open.
Probably a lot, to be honest. The systems are fairly robust, and getting it to do something it shouldn't is difficult. Getting it to just stop working, though, is a lot easier.
4730029
Yes, in two forms. One is due to a lack of information/appropriate test tools--we had a late-model Ford that had a problem with its infotainment system that we could not fix or even properly diagnose. It turned out that it needed a software update.
And the other is the customer is unwilling to spend the money. Right now, I have a Dodge Intrepid that has a permanent misfire on cylinder number two (and it's had this misfire for over two years). The owner wants us to make it run better without fixing the misfire, and the manager didn't choose to just run him out the door.
That's the thing. And I'll be honest, there are a lot of times where I ask the manger how far the customer wants me to go. Because we don't want to get into a situation where we're spending hour upon hour trying to diagnose something and not getting paid for our time.
4730039
Maybe when I get enough of them writ, I'll put them all together and sell it on Amazon.
I'd never thought that this was something people wanted to hear about, to be honest.
4730401
Well... I'm kinda' in the sales side of things. And you're good at fixing things... You think theRedBrony's up for some ownership things?
4730076
This Ford truck that I just put an engine in also kicked my butt, but that was more because the manager didn't want to charge the right amount of labor, or replace some things that clearly should have been replaced.
Yeah, I never would have expected it out of something that old.
Not as weird as that Teeves (I think it was) system that was, like, invented by Renault or something, and it was an all-in-one master cylinder and brake booster that was ungodly expensive. Used on some expensive foreign cars and also some Chrysler and Mitsubishi products.
Because I live in the sticks, I drive enough trucks and Astro Vans to be used to how Hydroboost feels.
4730132
Maybe this will be my breakthrough into paid writing. Huh.
4730161
Is that the one that has the little box right by the master cylinder, or is it the type that has the tube on the framerail that consists of a spring and a couple of wires?
Those fail, too, and I'd rather replace a hydroboost unit than a vacuum booster. Although in a truck, there's not much difference, 'cause you've got lots of space.
Will do!
4730226
Pretty much my feelings on the matter.
4730314
Well, mechanics can make that mistake, too. At least on this truck, I can sleep well knowing that it needed every part that we replaced, although it would have been much better if we'd let the customer know about that up front, rather than after doing the first and second repairs.
That's also why I always try my best to eliminate all potential causes of failure before condemning an expensive part.
4730332
That's one of my favorite gifs. I have to assume that they knew what would happen.
Oh, man, it was a total nightmare. But at least it's gone.
Someday maybe I'll blog about fixing the four wheel drive on that guy's other truck. That was also a bit of a nightmare.
4730403
Luckily (for me) we don't do internal transmission repairs. We pull them out and either replace them with a reman, or send them to a rebuilder.
4730409
You Canadians are weird.
Is that something that you can bill for? Do you get your shirts through a company? I can't tell you how many shirts and pants I've ruined in the shop, but the shop pays for them, so I don't care all that much when it happens.
4730424
Where would we set it up, anyways? It'd be a long commute for someone
4730433
At least it wasn't air-over-hydraulic. Those be a bitch.
4730451
Luckily, something that I don't have to work on. But I can imagine.
4730443
Look in any major club circuit and you'll find some, same with foam parties.
We tell the office, office bills the client and we USUALLY get new shirts... That's usually for if the office isn't told it's a paint party and the shirt stains. If it doesn't stain or the office is informed in advance to warn us to wear old shirts then we don't. So, a crapshoot.
4730435
we had to replace the condenser on our HVAC system bought the first the part was DOA so we returned it and got another It also was not working turned out the wiring diagram for the unit is incorrect for the system ahd to line trace and mark the control circuits
4730456
Only brake system I've worked on that "exploded violently" was a valid fault.
4730432
my ABS is the tube type on the frame witch all the bolts ware rusted to crap.
and i agree the hydroboost is much easier to change and work with.
4730426
Funny, I always thought it was a Bosch product. But yeah, that's the one I'm talking about, it's on a lot of the early 90s high-end Caravans/T&C's. It's similar to regular hydroboost, except it uses its own brake fluid pumped electrically to do the assisting. So the pedal feels the same kind of awkward. Actually, it's the same as modern hybrid brake systems. IIRC, to bleed the brakes, you just keep the pedal pressed down, and it pumps fluid continually by itself. Which is actually then just like an 80s Rolls Royce, except that uses teeny tiny little camshaft driven pumps, and it's literally two whole brake systems attached to one pedal. Literally.
This video reminds me of the Turbo Encabulator video
This is one of those things that I'm glad someone else is working on. There's apparently a similar situation going on at work. We were supposed to inspect a regulating outlet from one of our dams back in July. When we're in there, the only other outlet for water is through the two generating units in the powerhouse. Unfortunately, there's a gremlin living in Unit 2. They don't want to take the regulating outlet out of service unless both units are available to pass water, because if the only operating one were to trip offline, it'd dry up the river.
Ironically for this story, I think part of the time it's been down is for the brakes.
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4730408
Not a whole channel, but this is one of my favourite engine build timelape.