brakes

[akrhino]

brakes would not release until it sat for a bit now brake pedel is still stiff anyone know what that might be

 

[Recovry4x4]

Blocked compensating port in the master cylinder, bad air pack, bad rubber hoses or a combination of the above.

 

[54reo]

No free play in the adjustable push rod from the peddle to the MC.

i.e. the brakes are "applied"

(happened on mine once)

 

[bigmike]

Check freeplay first. Go to compensating port next. Go to airpack last.

I had a similar problem. Brake pedal got harder as you drove. Got the point that the brakes locked up. If you let it sit, it was all good again. had no freeplay...still didn't fix it. Changed master cylinders and upon inspection of the removed M.C. I found the little compensating port was mucked up. Cleaned it with a very small rat-tail file and now I have me a prefectly good back up M.C. Problem solved. BTW, I did check and oil my Airpack just to be sure.

 

[Big Mike's Motor Pool]

mine locked up before. my airpack was trashed inside. lots of rust and gunk built up in it. it was an easy rebuild with basic hand tools. i found that opening the service glad hand, drivers side one, would vent and unlock the brakes to move the truck. i was able to drive the truck like normal down the road with the service side open.i wouldnt reccommend going down the road like that though. dont know how safe that is.

 

[snoplay]

any one have a diagram of the master cyl. that shows the comp port?

 

[Barrman]

If you pull the master off and then pull the guts out. Look down through the cap hole. You will see two holes in the bottom of the resevoir. A big one and a small one. The small one is your compensating port. If you can't see it from the top, look down the cylinder bore and you will see the place for it. Use a paper clip or something to open it back up again after you take a hone to the bore to smooth it out.

Since the MC's are kind of a pain to take off, order a rebuild kit before you start. That way you will only have to do it once.