Engine/Transmission (1994 - 1998) Brake Question

[fire8033]

I am starting to have a problem with my brakes, at idle speeds, like when braking to turn around, the brakes are rock hard however the truck still moves. Any ideas would be great and thanks in advance, this site saves us alot of money!!!!

 

[hsmith]

Sounds like a booster, vacuum problem. The brake booster is a common culprit on these trucks. You might want to tap a vacuum gauge into the system to monitor the inches of vacuum at idle.

 

[fire8033]

Thanks for the information, does anyone have a link to a detailed way to test the vacuum, what amount of vacuum I should have, and how hard is it to change????

 

[hsmith]

Tee a vacuum gauge into the system anywhere, the small lines are easier. Should be a minimum of 18 inches, and not take long to build to that point. A real common place for a leak is below the drivers battery at the cruise servo. Don't think it could cause a big enough leak to keep the brake booster from working though.

If you are asking how to change the hydraulic vavle, just unbolt, remove lines, and re-install. Be sure to bleed rear brakes when finished.

 

[hsmith]

Oops, wrong thread. But still check the vacuum the same way. Booster R&R is pretty straight forward. Remove the clip from the pedal under the dash so the rod will come off, the unbolt MC and booster.

 

[Matthug]

First check the main feed tube to the booster, mine was barely connected and I hose clamped it. It looked like it was about to fall right off and didn't look like it was getting a great seal. Good thing I caught it, happen to see that when I installed my AFC kit.