Gee, how come disc brake pads don't just plain EXPLODE, since they are in constant contact with the rotor throughout their WHOLE life span?

Regardless of whether my method is right or wrong (it's never failed me before), unless you have the brakes at least "close" to adjusted right, chances are you're wasting your time or money.

Besides, if they did go out of adjustment and get severe enough to cause excessive pedal travel or the need to pump the brakes, there are likely more serious underlying problems, such as a broken adjuster cable, seized adjuster, broken springs or even missing hardware from a previous idiot into the brakes.

My point was and still is, if you have a low pedal, check the rear brakes FIRST.

Mark.

 

Mark, I agree with you that rear adjustment is critical on these trucks, but my point is that it should not be so critical that it causes complete brake system failure. It is too fine a tolerance, especially in view of the millions of other similar brake systems in the world that function perfectly. It is just a cruddy system, in my opinion. The sudden to the floor brake failure thing is hard to explain with adjustment, again in my opinion...Mark

 

That's because when a drum brake shoe is contacting the drum without hydraulic pressure, it's back is against the wall, metal to metal. When it heats up and expands, it gets tighter.

The disk brake pad, however, has nothing but the piston with no hydraulic pressure to overcome, so it just backs off a little bit. If the piston seal is bad and the piston gets grit in it so it can't relax, then it overheats and wears rapidly, just like the misadjusted brake shoe. A common failure is when the caliper slides get sticky, and then the backing disk pad wears rapidly for the same reasons.


The only reason the pedal will go to the floor with the failure of one circuit on these trucks is by design. To get enough leverage to apply ample braking force to the remaining circuit without vacuum boost, the pedal stroke has to be lengthened. The second stroke will fully apply the remaining circuit under any conditions.

Most cars, which are much lighter, can be designed so the overstroke is within the available pedal travel, and you can get full braking on the remaining circuit with the pedal just above the floor. It's a matter of weight, and compensating for potential double failure which would be likely in a collision with severe maneuvering situation.

Considering what they're stopping, and the primitive state of the ABS systems of the day, these are pretty good brakes.

 

That may or may not be true, but when you have no brakes when driving in traffic, that is a big problem regardless of why. If it is true, you are saying that they designed for you to have no brakes in that situation? That sounds rediculous. There are also many times that there is no time for a second stroke. THESE BRAKES ASPIRATE but you are entitled to your opinion. Rube Goldberg would be proud...Mark

 

Would you rather have half brakes, or full brakes in one second?
Regardless what the gurus in the present administration think, you can't change natural laws with congressional action or executive order. You have to learn to compensate for them. The first time you notice low pedal, find out why, rather than wait til you get into a tight situation and you fail to make said compensation in your panic, thus illustrating yet another natural law. (2 solid objects cannot occupy the same space)

 

You don't get it, my brakes went to the floor WITHOUT stopping. That is not half, that is all. You obviously did not read the entire thread, I no longer have this problem. I wish that I could know it all like you, that would be sweet..Mark

 

Sorry. I don't have the time or patience to read, re-read, analyze, and try to understand every word you write.

If your pedal went all the way to the floor, and wouldn't pump up, you had lost both circuits at that time. They usually don't fail simultaneously without warning, like MC leakage.

My comments stand as stated.

 

Yup these brakes make folks go crazy! My old 90 ctd in 2000 went to the floor a few times and scared the wazzu out of me, had to dig cotton outta some strange places.

 

I can respect a man that stands his ground, right or wrong, I love the social skills that most engineers that I have ever known have, non-existent. It makes me wonder how procreation happens. If you don't feel the need to read the thread, I don't feel the need to respect your know it all opinion. You may recall that this discussion is like deja vu all over again...Mark

 

http://www.nizkor.org/features/falla...d-hominem.html

 

So why is it that it seems like every time you come into a discussion on brakes, we end up with one person saying that the brakes on these trucks are absolute junk and the only way to fix them is a disk conversion?

Perhaps he read more than one thread before and knows how it's going to go?

SOP for the democratic par, wait, for politicians in general.

 

I. When did I ever say that the only way to fix them is a conversion?
2. Mr. Martin assumes that the brakes did not pump up on the second stroke, when did I ever say that?
3. Mr Martin says that he didn't read the thread, but comments on something that was covered in the thread.
4. This is not my first go around with mr. Know it all.
5. What makes you think I am democrat?
6. Mr. Martin says that the ONLY way for the brakes to go to the floor is circuit failure. He apparently doesn't realize how common it really is.
7. maybe myob and don't editorialize. Nobody knows everything about these trucks and that includes me, you and him...Mark

 

Yea I just logged back onto the forums after a while to figure out my brakes, Guess I'll be replacing wheel cylinders again i didn't realize there was a big issue with them crapping out, maybe I'll order some Bendix ones from Rockauto and stop buying the junk NAPA ones.

 

Well, from personal experience.... not that I claim to know everything.... the napa hydraulic parts I've bought have failed. THe bendix parts I've bought have not failed ..... as of yet.

So.... let us know how it goes, and then I can order new bendix wheel cylinders to replace the crapo defective-o-s that I have now....

 

03-15-2013, 09:25 AM #25
https://www.dieseltruckresource.com/...n-t310851.html

Yesterday, 03:52 PM #34
Yesterday, 04:12 PM #36
This thread

That isn't exactly what I said.
Sorry. I don't have the time or patience to read, re-read, analyze, and try to understand every word you write.

I made my living for awhile designing glycol based run around heat recovery systems. The math involved is considerable when you consider viscosity, laminar flow, turbulance, pressure, flow, losses through exchangers, etc. However, I still only have a thimble full of knowledge compared to your buckets.


Pray tell what else will make the pedal go to the floor?

Mark, you're beginning to get on my nerves a bit.