Brake Fade

[hoodshauler]

I know this is a stupid question. I have seen the answer here a hundred times but to be honest I am too lazy today to go hunting for it. With that said Tanyas truck just started the brake pedal fade, when you apply the brakes the pedal catches for a minute then goes to the floor. I am thinking the master cylinder? I just put new brakes on all the way around today and all the slaves looked fine. still need to check for air but dont think that is my problem.

 

[sassyrel]

booster--the early ones did that--they changed the booster later--end of problem---around 95?????

 

[Mr_Roboto]

If it goes to the floor it is most likely the master cylinder.

I recommend a "new" master cylinder, remans can be of questionable quality. Of course the Chinese "new" masters are too.

 

[icanfixall]

If you didn't open up the hydraulics side of the brakes you may have a master cylinder problem. Its either that or the rear brakes are way out of adjustment. The shoes are supposed to be a maxium of about 25 thousands from the drums. No, I don't know how to get this measurement but thats what I know. Try this. Set the parking brake, then apply the brake peddle. Depending on what happens will tell you whats wrong. If the peddle now stays up off the floor its the rears way out of adjustment. If it still drops to the floor then its the m/c. Post back what you find.... Even if I'm wrong.... I can take it.....

 

[hoodshauler]

Will get back with you tommarrow. Will get a M/C and go from there.

 

[DieselChemist]

You can check the master by disconnecting the lines and plugging the master and then seeing if it fades. It could also the rabs valve, if it has antilock. By checking the master that way it would tell you if it is in the master or after the master.

 

[hoodshauler]

Replaced the master and fixed the problem