Archived sticking brakes!

[Jonny-K5]

my dads truck ( 99 2500, auto, 2wd, 200k) has recently had a sticking brake pedal. here's what happened:



the truck has aftermarket rear discs , they were leaking, we could never get the ebrake to work good, so we took it into a repair shop. they replaced the rear calipers and rotors and disconnected the parking brake. stopped great for about a month.



then the brakes started sticking. he said the pressure wouldnt release and the brakes were locking up. towed it back to shop. mechanic said front calipers were sticking and master cyl. was no good. replaced both. as soon as my dad drove away he noticed the pedal would come back up. went back to mechanic and he said feels fine to him.



but of course its not fine. the brake light stays on unless you pull the pedal up with the top of your foot. they drag at a every brake application unless you pull it back up. you can actually hold the truck still ingear for a second or two if you push the pedal hard enough.



what could be causing this?cheap parts? wrong fluid? air in lines? antilock brake malfunction? please help.



Jon

 

[Joe Mc]

I had a sticky front right on another car some time ago. Replaced all kinds of stuff until I was told to replace the brake hose. Snap! that's what it was. The rubber cracked inside the hose creating a "flap" (or effectively a check valve) this wouldn't allow fluid return and held the caliper from releasing. If it is both rears that are staying applied it could be the hose from the frame to the rear housing. Wouldn't hurt checking? 99 has vacuum assist, I wonder if something is going on there - what about the little blue resevior cylinder that's supposed to provide a 2 - 3 pump stop if the assist fails? Just guessing here - good luck.

 

[Jonny-K5]

are you sure it vaccum assist? looks like the hydro setup ive seen on one ton chevy's, and no big round booster like there is on vaccum brakes. actually i think its a '99. 5, if there is such a thing. not sure what wheel its doing it on, but i think the front left was getting hotter than the right. my dad has a set of SS brake lines in a box somewhere, maybe i'll try swapping those on and bleeding the brakes real good.

 

[Joe Mc]

Not sure - only going by my 99 which has vacuum. The one you are working on should be easily identifyable as you've already figured out by the lack of a big diaphram chamber behind the master cylinder. If you have the SS lines (jealous) put them on. I just found out there is a small aluminum block immediately after the lines leaving the m-cyl which has a valve of sorts that needs to be lifted or depressed (not sure?) when bleeding the brakes, or the pedal could be low. Check the manual
to be sure - I need to do likewise.

Keep us posted.