Auto Mechanic Question

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retiredjg
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Auto Mechanic Question

Post by retiredjg »

Last year, my car didn't pass inspection because the brake pads were contaminated. The tech thought it might be a (edit) wheel cylinder (not master cylinder) problem. I took it too a mechanic, they checked the rear brakes and wheel cylinders, and replaced the brake shoes. There was no repair done - just replacing the brake shoes.

One year later, my car didn't pass inspection because the brake pads were contaminated. :roll: The tech thought it might be "seals". I talked to the mechanic today. Neither of us remembers why he didn't repair anything last year - just replaced the contaminated brake pads. He's going to actually take a look at the car tomorrow.

It appears to me that last year, he just put on new shoes and passed the car for inspection without actually fixing the problem. Is there any reasonable explanation for this?

Car is a 2000 Toyota 4-Runner.
Last edited by retiredjg on Fri Sep 30, 2011 9:24 am, edited 1 time in total.
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norookie
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Post by norookie »

:D Sounds like BS to me. The imposition of the incredibility unrealistic possibility of you having bad (contaminated) brake pads is simply generating income for the shop. Your auto stops or it does not, you're parking brake works or it does not. Plus, consider the costs they incur for buying the inspection equipment. In fact I myself did inspections in the 70s and 80s till stickers went to 5 bucks and emissions started. You're getting hosed. Find a new place to go. JMO~
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Post by retiredjg »

norookie wrote::D Sounds like BS to me. The imposition of the incredibility unrealistic possibility of you having bad (contaminated) brake pads is simply generating income for the shop. Your auto stops or it does not, you're parking brake works or it does not. Plus, consider the costs they incur for buying the inspection equipment. In fact I myself did inspections in the 70s and 80s till stickers went to 5 bucks. You're getting hosed. Find a new place to go. JMO~
What you are saying may be correct, but it does not apply to this situation.

The shop that does inspections is a quick-lube type of place - they don't do any repair work and they don't recommend any specific shop to have the work done. And they did show me the goo all over the brake shoe.

My question is about the mechanic that replaced the shoes without fixing the leak problem. My question is if he could have checked the brakes/cylinders/seals and not found a problem when there actually was a problem that needed to be fixed.
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Post by klneutral »

I wonder what the "goo" on the brake material is. I can think of only two possibilities--grease or brake fluid and the latter seems much more likely.

It sounds likely that you have a brake fluid leak. This should result in the brake reservoir level going down over time. Have you noticed that happening? I suppose the leak could be slow enough to contaminate the brake material and still not cause the level to drop enough for you to notice.

I think you have a leak and the mechanic who worked on it should have found the leak. It is pretty likely that the leak would have left evidence on parts in the area other than just the brake material.
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Post by retiredjg »

If you take the brake drum off and look behind it, there is a little cylinder shaped thing at the top with appears to have rubber seal on each end. The little cylinder thing is the size of a fat tube of lip balm. That's where the goo is - mostly at one end of that little cylinder and onto the brake pads.

I didn't feel or smell it or whatever, so don't know what it is. Probably should have, but had something else going on at the time.

I do not think this is the master cylinder, but I think I understand that a leak in the master cylinder could throw stuff up in many areas, including that area.

Obviously, I don't know enough about what I'm talking about. :lol:

The brake fluid reservoir has not dropped enough to need to be topped off in the last year.
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Post by jwtietz »

What you are talking about is the wheel cylinder leaking brake fluid on the brake shoes in a rear drum system. If this is what it is, they are not pads they are shoes. The cylinder needs to be replaced (or rebuilt) and then bleed the system. It has nothing to do with the master cylinder which is under the hood of the car. If the shoes are covered with the fluid, you could wash them in solvent but it would be better to replace them.
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Post by norookie »

49957d1315367036‑ticking‑hammerish‑noise‑4runner‑drum_brake_diagram.jpg
toyota-4runner.org
362 × 205 - Attached Images
Similar ‑ More sizes Hope the pic comes out. I know the part your talking about but forget its name. These are not routinely replaced in a brake job. They are where the master cylinder, thats under the hood, pumps brake fluid to expand the shoes. Usually they replace the shoes, spring hardware kit, and sometimes the drum if it is out of spec and cannot be cut. It sounds like you may or may not only have to replace the one leaker. So its brake fluid leaking on your shoes. I'm surprised it's not caused more problems, like the friction causing smoking, unless its driven only a little. I've had 3 4Runners. All were 10/10 rating IMO for reliability. :D I agree with the post above.
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Post by tibbitts »

retiredjg wrote:
norookie wrote::D Sounds like BS to me. The imposition of the incredibility unrealistic possibility of you having bad (contaminated) brake pads is simply generating income for the shop. Your auto stops or it does not, you're parking brake works or it does not. Plus, consider the costs they incur for buying the inspection equipment. In fact I myself did inspections in the 70s and 80s till stickers went to 5 bucks. You're getting hosed. Find a new place to go. JMO~
What you are saying may be correct, but it does not apply to this situation.

The shop that does inspections is a quick-lube type of place - they don't do any repair work and they don't recommend any specific shop to have the work done. And they did show me the goo all over the brake shoe.

My question is about the mechanic that replaced the shoes without fixing the leak problem. My question is if he could have checked the brakes/cylinders/seals and not found a problem when there actually was a problem that needed to be fixed.
Most leaks are just "relative" leaks. Almost nothing seals perfectly, but often you don't see "goo" dripping out, either. The situation can be halfway between. Particularly with something like a rear axle seal, for example. Over the course of a year, it could leak enough to contaminate the brake linings, but not be obviously defective. Maybe your car doesn't even have axle seals, I have no idea. But the concept is the same with wheel cylinder piston seals and related rubber parts. So maybe there wasn't a huge glaring problem, but still a problem. Maybe your mechanic just felt the old shoes were worn out anyway and that any possible leak wasn't bad enough to worry about yet.

It used to be that a brake job by default included disassembling calipers and wheel cylinders and replacing any worn metal parts inside (and always rubber parts.) I don't believe that's the default case today.

Paul
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Post by klneutral »

jwtietz wrote:What you are talking about is the wheel cylinder leaking brake fluid on the brake shoes in a rear drum system. If this is what it is, they are not pads they are shoes. The cylinder needs to be replaced (or rebuilt) and then bleed the system. It has nothing to do with the master cylinder which is under the hood of the car. If the shoes are covered with the fluid, you could wash them in solvent but it would be better to replace them.
After OP gave additional information, I agree completely with jwtietz. The master cylinder under the hood builds up pressure in the line when you press the brake pedal. That pressure is transmitted through the fluid to the cylinder at the brake to generate a force pushing the brake shoes apart into the drum. The leaking cylinder at the wheel needs to be replaced and I think the guy who replaced the shoes should have noticed the "goo" and recommended the fix.
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Post by retiredjg »

Thanks for the replies. I've gotten some "education" using pictures (thanks norookie) and now know the proper names. Forget master cylinder - that was me using the wrong term.

The part in question (fat lip balm thing) is the wheel cylinder aka slave cylinder. I had thought those were two different things, but looking at different pictures, they apparently are the same. That seems to be the piece that is leaking. At least, that is where most of the goo is.

That is what the mechanic checked last year, but did not replace. I don't know why because the repair ticket says to check the wheel cylinder, but there is no cost for fixing or replacing. When I talked to him yesterday, he didn't know or remember why - but he was not looking at the brakes. He is going to look today and we'll figure out what to do.

I have no reason to believe this guy is cheating me. The only thing I could say is maybe he was lazy or just missed it. Or trying to save me money by not doing an unnecessary replacement.

So the question still remains - could the wheel cylinder be leaking and the leak not be apparent when the wheel cylinder is checked? (I don't know where the goo was last year or how much was there - just that the brake shoe was contaminated).

Unfortunately, my appointment is in a couple of hours - not sure how many people will see this by then.
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Post by klneutral »

Here is the logical sequence of thinking (diagnostics):

The shoe is contaminated.
Why is the shoe contaminated?
What is likely to contaminate it?
Probably brake fluid.
Where could the brake fluid be coming from?
Nearby components.
What components are nearby?
Wheel cylinder and brake lines.
Is there a leak in the wheel cylinder or lines?
How could I find the leak?
Look for wet, stained spots.
Pressurize the system (stand on the brake pedal for a while) and look for fresh liquid.
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Post by retiredjg »

Makes sense to me. So I guess you are voting for incompetent or lazy. :lol:

Anybody want to vote for the problem was so small at the time, a good mechanic might have taken reasonable steps and not found the problem?

Or, everybody has a bad day and could miss something?

I do have one question, klneutral, about "pressurize the system"....there is some small niggle in the back of my head that says you are not supposed to do that with the drum off. Am I imagining that?
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Post by cleosdad »

retiredjg wrote:Makes sense to me. So I guess you are voting for incompetent or lazy. :lol:

Anybody want to vote for the problem was so small at the time, a good mechanic might have taken reasonable steps and not found the problem?

Or, everybody has a bad day and could miss something?

I do have one question, klneutral, about "pressurize the system"....there is some small niggle in the back of my head that says you are not supposed to do that with the drum off. Am I imagining that?
retiredjg, I was a mechanic years ago so I will try. If you do indeed have rear brake shoes and a drum versus pads and rotor taking off brake drum is only way to inspect wheel cylinder. You could then tell if it is leaking. I never had to apply pressure. I cannot comment on the mechanic but if it is a concern take it to another shop. I WOULD NOT trust a quick lube place with this. We have a 96 4Runner with 189000 miles. The brakes are original with 70% wear left on them. Good luck.
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Post by klneutral »

retiredjg wrote:I do have one question, klneutral, about "pressurize the system"....there is some small niggle in the back of my head that says you are not supposed to do that with the drum off. Am I imagining that?
Good point. You would want to put the drum back on, pressurize the system, and then remove the drum to look for new leaked fluid.

One would think the drive in would have pressurized the system enough to produce the wet spot you are looking for.
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Post by retiredjg »

cleosdad wrote: retiredjg, I was a mechanic years ago so I will try. If you do indeed have rear brake shoes and a drum versus pads and rotor taking off brake drum is only way to inspect wheel cylinder. You could then tell if it is leaking. I never had to apply pressure. I cannot comment on the mechanic but if it is a concern take it to another shop. I WOULD NOT trust a quick lube place with this. We have a 96 4Runner with 189000 miles. The brakes are original with 70% wear left on them. Good luck.
It is definitely rear drum brakes. It is clear the wheel cylinder is leaking NOW. I'm not sure how clear it was a year ago when all the factual info I had was "rear brakes contaminated".

It is not a quick lube mechanic doing the work - that's is who did the safety inspection and said the brake shoe was contaminated - and why the car failed the safety inspection two years in a row.
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Post by cleosdad »

retiredjg wrote:
cleosdad wrote: retiredjg, I was a mechanic years ago so I will try. If you do indeed have rear brake shoes and a drum versus pads and rotor taking off brake drum is only way to inspect wheel cylinder. You could then tell if it is leaking. I never had to apply pressure. I cannot comment on the mechanic but if it is a concern take it to another shop. I WOULD NOT trust a quick lube place with this. We have a 96 4Runner with 189000 miles. The brakes are original with 70% wear left on them. Good luck.
It is definitely rear drum brakes. It is clear the wheel cylinder is leaking NOW. I'm not sure how clear it was a year ago when all the factual info I had was "rear brakes contaminated".

It is not a quick lube mechanic doing the work - that's is who did the safety inspection and said the brake shoe was contaminated - and why the car failed the safety inspection two years in a row.
retiredjg, Since it is leaking I would rebuild/replace both rear wheel cylinders at the same time. I would also check brake shoes if there is excess fluid on them. Funny, when I was a state inspector (years ago) we never checked rear brakes.
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Post by retiredjg »

cleosdad wrote:
retiredjg wrote:
cleosdad wrote: retiredjg, I was a mechanic years ago so I will try. If you do indeed have rear brake shoes and a drum versus pads and rotor taking off brake drum is only way to inspect wheel cylinder. You could then tell if it is leaking. I never had to apply pressure. I cannot comment on the mechanic but if it is a concern take it to another shop. I WOULD NOT trust a quick lube place with this. We have a 96 4Runner with 189000 miles. The brakes are original with 70% wear left on them. Good luck.
It is definitely rear drum brakes. It is clear the wheel cylinder is leaking NOW. I'm not sure how clear it was a year ago when all the factual info I had was "rear brakes contaminated".

It is not a quick lube mechanic doing the work - that's is who did the safety inspection and said the brake shoe was contaminated - and why the car failed the safety inspection two years in a row.
retiredjg, Since it is leaking I would rebuild/replace both rear wheel cylinders at the same time. I would also check brake shoes if there is excess fluid on them. Funny, when I was a state inspector (years ago) we never checked rear brakes.
It is now standard procedure here in my state. But they only check one side!

I gather (internet talk) that rebuilding is not as common as it once was. Probably going for replacement. Probably just do both.

Thanks for the help! I'm off to the garage!
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Re: Auto Mechanic Question

Post by Dagwood »

retiredjg wrote:Last year, my car didn't pass inspection because the brake pads were contaminated. The tech thought it might be a (edit) wheel cylinder (not master cylinder) problem. I took it too a mechanic, they checked the rear brakes and wheel cylinders, and replaced the brake shoes. There was no repair done - just replacing the brake shoes.

One year later, my car didn't pass inspection because the brake pads were contaminated. :roll: The tech thought it might be "seals". I talked to the mechanic today. Neither of us remembers why he didn't repair anything last year - just replaced the contaminated brake pads. He's going to actually take a look at the car tomorrow.

It appears to me that last year, he just put on new shoes and passed the car for inspection without actually fixing the problem. Is there any reasonable explanation for this?

Car is a 2000 Toyota 4-Runner.
The problem here is that when a competent shop does a brake job, they inspect the calipers and the wheel cylinders and associated components. The shops that do this more thorough work cost more, but here is an example of where you get what you pay for. Peruse the Toyota forums and find the shops / dealers that have a good reputation for service. Your car should never go in for a brake job, especially if it is more than a few years old, without the tech checking the calipers, wheel cylinders, lines, etc. That's the difference between having a pro and quickie shop. It's also the difference in cost between a real brake job and an $89.99 special.

For this car, both rear drums should be overhauled given the age of the car. And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
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Post by retiredjg »

Ok. Here's the news from the mechanic.

He feels the problem is not leakage from the wheel cylinder, but from the rear axel. I guess much of that thinking comes from the smell of the stuff. It's been many years, but I recall brake fluid has a somewhat acrid odor. It does not smell like brake fluid to me.

This mechanic says he does not have the tools needed to do the job and is referring me to a shop in a nearby town down the road. He is going to provide new brake shoes himself. I suppose that will save a little money. However, this does not sound like a cheap repair.

Apparently, there is no problem on the other side although I was not there when he looked at that side.

Thanks for the help everybody! This is a 12 year old car, but has less than 90k miles on it, so probably a lot of life left. But I suppose some stuff wears out by age in addition to wear and tear and I live in a place with snow (and therefore salt) for several months a year. I suspect this is the beginning of at least 1 expensive repair a year until I sell it. I had hoped I was done this year (almost $900 in tires a few months ago!) but apparently not. :?
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Re: Auto Mechanic Question

Post by retiredjg »

Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
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Re: Auto Mechanic Question

Post by cleosdad »

retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
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Post by campos202 »

I think your mechanic has gotten it right. Brake fluid is not a lubricant and wouldn't cause a gummy residue like you describe. Fluid from the rear differential is a lubricant (it is very similar to motor oil) would create a gummy residue when combined with the dust from your brake shoes. 4 wheel drive vehicles are notorious for fluid leaking from the transfer case/rear differential as they get older in years the rubber gaskets/seals dry out and require replacement. I can't tell you how many times I replaced seals/gaskets on my 12 year old Subaru just to have something leak somewhere else in another year or so.
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Re: Auto Mechanic Question

Post by retiredjg »

cleosdad wrote:Just had timing belt...
:shock: OMG.... As many Toyotas as I've had and I had forgotten about the timing belt phenomenon....:roll: Guess I'll work that in next year.
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Re: Auto Mechanic Question

Post by fishnskiguy »

cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
Not changing brake fluid was not a big deal many years ago. In the age of anti-lock brakes, it is a big deal.

Chris
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Re: Auto Mechanic Question

Post by tibbitts »

fishnskiguy wrote:
cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
Not changing brake fluid was not a big deal many years ago. In the age of anti-lock brakes, it is a big deal.

Chris
I'm not sure it's that different now, except that with ABS, my understanding is that you won't change the fluid in the ABS unit unless you have the hardware and software to properly route the fluid through the ABS. Before ABS, it was pretty easy to push fluid through the whole system from end-to-end.

Probably the main reason for changing the fluid is to restore its heat resistance, and most of that probably applies to the fluid that's in the cylinders or calipers. That you can still flush out somewhat with the usual techniques. But if you're trying to clean out the ABS itself, I'm not sure most brake flush jobs people have done actually do that. In theory, the water in the fluid that causes the loss of heat resistance also cause corrosion in the ABS control module, but I'm not sure that's as big an issue as the loss of heat resistance itself is. For sure, ABS modules are super-expensive, but I'm not sure how many fail from internal corrosion.

Paul
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Re: Auto Mechanic Question

Post by cleosdad »

fishnskiguy wrote:
cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
Not changing brake fluid was not a big deal many years ago. In the age of anti-lock brakes, it is a big de

Chris
We have ABS on both cars. Every mechanic I have asked think it is not needed but will gladly charge for it.
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Post by Redbelly »

#1 rule for a competent mechanic is to determine why a part failed before replacing it. Shoes contaminated? Why?

Your mechanic did not do an analysis, - he just replaced the shoes. Now you have the same problem all over again.

Re replacing brake fluid - there are two main issues. The fluid is hygroscopic and gets contaminated with water over time. This contamination can corrode brake parts and worse, will boil under heavy brake usage (think towing a trailer in the mountains). Once it boils, you have no line pressure and thus no brakes.
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Re: Auto Mechanic Question

Post by SamB »

tibbitts wrote:
fishnskiguy wrote:
cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
Not changing brake fluid was not a big deal many years ago. In the age of anti-lock brakes, it is a big deal.

Chris
I'm not sure it's that different now, except that with ABS, my understanding is that you won't change the fluid in the ABS unit unless you have the hardware and software to properly route the fluid through the ABS. Before ABS, it was pretty easy to push fluid through the whole system from end-to-end.

Probably the main reason for changing the fluid is to restore its heat resistance, and most of that probably applies to the fluid that's in the cylinders or calipers. That you can still flush out somewhat with the usual techniques. But if you're trying to clean out the ABS itself, I'm not sure most brake flush jobs people have done actually do that. In theory, the water in the fluid that causes the loss of heat resistance also cause corrosion in the ABS control module, but I'm not sure that's as big an issue as the loss of heat resistance itself is. For sure, ABS modules are super-expensive, but I'm not sure how many fail from internal corrosion.

Paul
I own a 1995 Subaru Legacy L with ABS. I also own the shop manual (3 volumes). The procedure described in the manual for changing the brake fluid is to have an assistant (my wife) pump the brake several times and hold while I carry out the bleed sequence, topping up the reservoir after each wheel.

I just looked at the manual for my Honda Civic (2009). I have not changed the brake fluid in it yet. Surprise, surprise, it is the same procedure, but a different wheel sequence. It looks like I spend all of $5 to change the fluid in the Honda. It has ABS also.

I think you should actually go look at the manual before hallucinating about ABS. The mechanics are laughing all the way to the bank.

Years ago I paid a dealership to change the brake fluid. The car came back with spongy brakes. They did a crappy job. They could not even take the time to get all of the air out of the system. Hint: if you do it yourself the trick is for your wife to never take her foot off of the brake pedal. The system must stay pressurized from start to finish. Train your wife and maybe you can start a business changing brake fluid and end up doing a better job than most of the dealerships.

My brakes are rock solid.

Sam



Sam
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Re: Auto Mechanic Question

Post by Dagwood »

cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
The reason you change brake fluid is that it is hygroscopic -- it tends to absorb moisture over time. Brake fluid essentially acts to transfer the physical action of your foot pressing on the brake pedal to the brake caliper pistons (and in this case, the pistons inside the drums that actuate the shoes). You do not want brake fluid to essentially "compress" and not transfer that force efficiently because then you will be losing braking effectiveness. Moreover, the presence of excessive moisture inside the system can lead to premature brake master cylinder failure, or failure of the calipers and brake wheel cylinders due to corrosion. (Bear in mind a very minute amount of corrosion inside of one of these systems will cause a problem.) Thus most manufacturers will recommend a change based upon time or mileage, at least on all the cars I have owned. Chances are, if you read your manual, Toyota also recommends a change. Thus, assuming Toyota does recommend a change, don't confuse the fact that you have been lucky in not maintaining your car properly with what is in fact proper maintenance according to the manufacturer.

Finally, brake fluid changes are not a big deal. However, on cars with traction control -- systems where the car has the ability to pulse individual brake calipers to help provide traction, or on cars with stability control -- basically the same system but on all four wheels combined with yaw and steering angle sensors -- brake fluid changes typically require either a special process or a special tool. It's not heart surgery to bleed these cars either but it is more complicated than the simpler process with which most folks might be familiar. This is why most shops today will charge a $100 or so for a fluid change on these newer cars. It's like most things in the sense that there is a price to pay for the greater safety and complexity associated with these systems; however, the fluid changes are generally only done every 2 or 3 years and it is not that expensive.

And all of this is, btw, why if you drive your car every day and you put your kids and family in it, you should make sure you've read the maintenance schedule / requirements for the car and that you have that work done by a good shop, not a shop where the idea is to glue everything back together if you present the right coupon. The goal is to be smart and informed, and have the car serviced properly. The few bucks you save otherwise won't amount to much if you are in an accident because your car didn't stop or otherwise perform properly.
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Re: Auto Mechanic Question

Post by cleosdad »

Dagwood wrote:
cleosdad wrote:
retiredjg wrote:
Dagwood wrote: And make sure that you are changing your brake fluid at the interval prescribed in the car's owner's manual.
Hmmm, had not even given that a thought!
Just my opinion, I have never changed my brake fluid and probably never will. Like I mentioned my wifes 96 4Runner has 189000 and we expect to get 250000-300000 on it. Just had timing belt, hoses, water pump, shocks, and tires put on. Someone is always offering to buy it.
The reason you change brake fluid is that it is hygroscopic -- it tends to absorb moisture over time. Brake fluid essentially acts to transfer the physical action of your foot pressing on the brake pedal to the brake caliper pistons (and in this case, the pistons inside the drums that actuate the shoes). You do not want brake fluid to essentially "compress" and not transfer that force efficiently because then you will be losing braking effectiveness. Moreover, the presence of excessive moisture inside the system can lead to premature brake master cylinder failure, or failure of the calipers and brake wheel cylinders due to corrosion. (Bear in mind a very minute amount of corrosion inside of one of these systems will cause a problem.) Thus most manufacturers will recommend a change based upon time or mileage, at least on all the cars I have owned. Chances are, if you read your manual, Toyota also recommends a change. Thus, assuming Toyota does recommend a change, don't confuse the fact that you have been lucky in not maintaining your car properly with what is in fact proper maintenance according to the manufacturer.

Finally, brake fluid changes are not a big deal. However, on cars with traction control -- systems where the car has the ability to pulse individual brake calipers to help provide traction, or on cars with stability control -- basically the same system but on all four wheels combined with yaw and steering angle sensors -- brake fluid changes typically require either a special process or a special tool. It's not heart surgery to bleed these cars either but it is more complicated than the simpler process with which most folks might be familiar. This is why most shops today will charge a $100 or so for a fluid change on these newer cars. It's like most things in the sense that there is a price to pay for the greater safety and complexity associated with these systems; however, the fluid changes are generally only done every 2 or 3 years and it is not that expensive.

And all of this is, btw, why if you drive your car every day and you put your kids and family in it, you should make sure you've read the maintenance schedule / requirements for the car and that you have that work done by a good shop, not a shop where the idea is to glue everything back together if you present the right coupon. The goal is to be smart and informed, and have the car serviced properly. The few bucks you save otherwise won't amount to much if you are in an accident because your car didn't stop or otherwise perform properly.
Did you read my post? My cars are meticulously maintained. $100.00? We just spent $2600 on proper maintanance and tires. I was an ASA certified mechanic. The shop we take it to specializes in Toyotas and expensive imports. I think you should consider a different shop.
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Post by Dagwood »

I don't want to argue with you, but the reality is that most manufacturers recommend brake fluid changes for the reason I mentioned. Ignoring that service recommendation and spending money on other wear items does not negate the need to change it, if it is recommended by the manufacturer. Mechanics are knowledgeable but not more so than the engineers who designed the car.
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Post by cleosdad »

Dagwood wrote:I don't want to argue with you, but the reality is that most manufacturers recommend brake fluid changes for the reason I mentioned. Ignoring that service recommendation and spending money on other wear items does not negate the need to change it, if it is recommended by the manufacturer. Mechanics are knowledgeable but not more so than the engineers who designed the car.
I don't want to argue either. I just checked my owners manual. It stops after 120,000 miles. We have 189,000 with ABS. No where does it recommend flushing the brake fluid. Only inspecting and replacing/repairing parts as needed as I religiously do.
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Post by pkcrafter »

jg, I got into this conversation late, but let's see if I've got it right.

Inspection shop said brake shoes were contaminated.

Repair shop replaced shoes, but did not fix source of problem.

Brake fluid leak? No? Gear lube leak? Mechanic says he can't fix that and recommends another shop. Is this mechanic the same one who replaced the shoes? If it is do not do business with him again. He changed shoes knowing full well he could not actually fix the problem. :evil:

If it is a gear lube leak, you need the axle seal replaced.

retiredjg
It is clear the wheel cylinder is leaking NOW
Are we back to not knowing what the problem is?
-------------------------------------

Note on changing brake fluid. Sixty to seventy percent of auto manufacturers now recommend brake fluid changes. Cleosdad, read your maintenance book to see if this is recommended. If you were a mechanic, I'm a little surprised you would opt for the full maintenance routine.

Brake fluid is hydoscopic, but the system is closed, so getting water in there is difficult. Changing fluid in a car with ABS isn't as easy as it used to be. The system should be put under vacuum because fluid in the booster/abs unit will not drain. Bleeding the brakes should not be required unless the system has been opened.


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Post by Dagwood »

cleosdad wrote:
Dagwood wrote:I don't want to argue with you, but the reality is that most manufacturers recommend brake fluid changes for the reason I mentioned. Ignoring that service recommendation and spending money on other wear items does not negate the need to change it, if it is recommended by the manufacturer. Mechanics are knowledgeable but not more so than the engineers who designed the car.
I don't want to argue either. I just checked my owners manual. It stops after 120,000 miles. We have 189,000 with ABS. No where does it recommend flushing the brake fluid. Only inspecting and replacing/repairing parts as needed as I religiously do.
Well then you have nothing to worry about.

Also, I went back and re-read my original post. I could see how it could come across as snarky or obnoxious. That wasn't my intent, but I could see that you would take some offense. So to the extent I was impolite with my post, my bad and apologies. Glad there is no argument and that you took the advice as intended. Best regards.
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Post by cleosdad »

Dagwood wrote:
cleosdad wrote:
Dagwood wrote:I don't want to argue with you, but the reality is that most manufacturers recommend brake fluid changes for the reason I mentioned. Ignoring that service recommendation and spending money on other wear items does not negate the need to change it, if it is recommended by the manufacturer. Mechanics are knowledgeable but not more so than the engineers who designed the car.
I don't want to argue either. I just checked my owners manual. It stops after 120,000 miles. We have 189,000 with ABS. No where does it recommend flushing the brake fluid. Only inspecting and replacing/repairing parts as needed as I religiously do.
Well then you have nothing to worry about.

Also, I went back and re-read my original post. I could see how it could come across as snarky or obnoxious. That wasn't my intent, but I could see that you would take some offense. So to the extent I was impolite with my post, my bad and apologies. Glad there is no argument and that you took the advice as intended. Best regards.
Dagwood, No offense taken. I may have come across as defensive. I believe we were both right. Best regards.Tim
ataloss
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Post by ataloss »

04 4 runner?

4 wheel disc brakes from what I can tell at edmunds

http://www.edmunds.com/toyota/4runner/2 ... =100336286
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Post by norookie »

ataloss wrote:04 4 runner?

4 wheel disc brakes from what I can tell at edmunds

http://www.edmunds.com/toyota/4runner/2 ... =100336286
OP said 2000. Rear Drums.
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cleosdad
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Post by cleosdad »

ataloss wrote:04 4 runner?

4 wheel disc brakes from what I can tell at edmunds

http://www.edmunds.com/toyota/4runner/2 ... =100336286
ataloss, I don't know if you are asking me but we own a 1996 4Runner. I am now going to watch my Cardinals try to beat the Phillies.
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Post by retiredjg »

pkcrafter wrote:Inspection shop said brake shoes were contaminated.

Repair shop replaced shoes, but did not fix source of problem.
Correct.
Brake fluid leak? No? Gear lube leak? Mechanic says he can't fix that and recommends another shop. Is this mechanic the same one who replaced the shoes? If it is do not do business with him again. He changed shoes knowing full well he could not actually fix the problem. :evil:
Yes, he is the same one who replaced the shoes last year. This could definitely be a reason not to use him again - I'm undecided at this point. It is possible that last year the contamination was so minor that he could not tell just what the problem was. Or maybe he suspected the right thing and thought I could get by for another year. I don't know. At least he didn't try to sell me new wheel cylinders when I didn't need them.

I did tell him I was concerned that he changed the shoes without actually fixing the problem. This was a year ago, so he doesn't remember why he made that decision, but he is throwing in new shoes (I'm taking them to the other mechanic) without charge.
If it is a gear lube leak, you need the axle seal replaced.
I believe this is what he has diagnosed.
retiredjg
It is clear the wheel cylinder is leaking NOW
Are we back to not knowing what the problem is?
No. It would have been more accurate for me to say "it is clear the wheel cylinder has lots of goo on it now". But his feeling is that this is being flung from the rear axle, not draining from the wheel cylinder.

I have to say thanks to everyone for all this help! I hope I don't get to this new mechanic and hear the problem is something completely different....
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