Brakes
 

I believe my brake booster is bad as it wont release the brakes when I stab it hard when some idiot is on a suicide run.

What would cause this. Or is my diagnosis wrong and its the master cylinder?

Re: Brakes
 

I would suspect front brake hose(s).

They can collapse internally and trap pressure.

Or a corroded caliper/piston.

K

Re: Brakes
 

I have no brake drag.

The issue only happens when the brakes are hit hard.

Re: Brakes
 

Open a bleeder when it does it next.
If there is pressure your brake hose failed.

Re: Brakes
 

pop the vacuum line off booster next time, if that release break pressure there is an issue with booster

When they do lock on how do you release them?

Re: Brakes
 

I had to replace my calipers due to a sticky one along with the hoses just because, amd the problem persists.

Re: Brakes
 

I will try that next time. Unfortunately it doesn't happen when I try to recreate the issue.

I pull the pedal up with my toes.

Re: Brakes
 

sounds like the problem is most likely mechanical in the pedal, pushrod, return spring.
remove the two nuts holding master to booster, pull master away from booster and play with the pedal.

A c10 style pedal box, may need the pivot shaft removed, cleaned and lubed. That was sometimes an issue even when these trucks were newish

Re: Brakes
 

bad booster usually makes for a hard pedal

Re: Brakes
 

The pedal pushrod is not mechanically attached to the booster/Master cylinder. The rod only rests in a pocket in them.. If pulling up the pedal releases the brake, something - a bushing, linkage piece - is binding, thus preventing the pedal from returning.. You may have to remove the complete pedal assembly in order to make repairs.

Re: Brakes
 

I will pull the pedal this weekend and grease the unit. Plus deburr any rough spots