I just installed a 4 wheel disc brake setup from PST and everything works but when I push down on the brake pedal it does not come back up unless I lift the pedal with my foot.Without lifting the pedal manually the brakes are on solid.The booster is holding vaccum and the push rod is not hitting anything.Could it be a brand new booster is bad?Has anyone seen this before?
Brake booster not releasing?hmmmm
- Thread starter dmaccons
- Start date
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BillGrissom
Well-Known Member
There should be a strong spring inside the MC to push the piston back. The only way I know to resolve it is to take the MC off the booster (leave brake tubes connected). If not enough room to test both, take the booster off the firewall and pedal.
Test the booster alone by pushing and pulling on the pedal rod w/ engine running to generate vacuum. It shouldn't take much pull to get the booster to return and it should act as a "follower", just following your hand (with a little stiction). If not, the valve internal to the booster must be bad. I have done this on a booster I rebuilt, just stealing vaccum from a running car.
Check the MC by pushing the piston in with a socket extension and see if there is a spring to return it.
I didn't go the high-dollar PST route. I just mounted a junkyard booster/MC from a later 90's Mopar on 74 booster brackets. In my experience, after-market stuff is not only high priced, but often suspect quality.
Test the booster alone by pushing and pulling on the pedal rod w/ engine running to generate vacuum. It shouldn't take much pull to get the booster to return and it should act as a "follower", just following your hand (with a little stiction). If not, the valve internal to the booster must be bad. I have done this on a booster I rebuilt, just stealing vaccum from a running car.
Check the MC by pushing the piston in with a socket extension and see if there is a spring to return it.
I didn't go the high-dollar PST route. I just mounted a junkyard booster/MC from a later 90's Mopar on 74 booster brackets. In my experience, after-market stuff is not only high priced, but often suspect quality.
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