Brake Pedal Stiff After Boost Leak Test

[->PrOjEcTGS<-]

Hey guys, today I did a BLT and pressurized the system to 30+ psi. Well, after I was all done I hopped in the car to go to work and before I started the car the brake pedal was very stiff. Normally the brake booster will hold on to vacuum for the first pump of the pedal. Not this time.

The only thing I can think of to cause this would be a failure of the one way checkvalve in the brake booster's hose. I read Calan's thread about his solution to a new brake booster hose. Would this be a viable option to fix this problem?

I have also noticed for some time now that after a long 3rd gear pull right after I let off the throttle the vacuum will be low at around 15in/hg instead of it's normal 20-21in. After a few seconds it will come back to normal. Could the hose be the culprit of this problem also?

 

[habitatguy187]

Logically it's gotta be the check valve or the booster itself. Start with the check valve of course since it's cheaper.

 

[lacroixdp]

I did the exact same thing a while back. Changing the check valve out fixed the problem.

 

[->PrOjEcTGS<-]

I did the exact same thing a while back. Changing the check valve out fixed the problem.

Before you changed out the valve did you have any weird problems with your vac like I'm having?

I'll change out the hose and put in a new check valve and see what I get.

 

[lacroixdp]

To be honest, I don't know if my vacuum was doing the same thing as yours or not - I wasn't paying attention to the gauge when this was happening. My pedal was doing precisely what yours was doing however. I also remember that when I shut off the car, the brake pedal became instantly hard. I could disconnect my check valve tomorrow and see if it does that if you'd like.