Weird brake pedal

eagleguy

Member
Joined
Apr 5, 2015
About a year ago I had my system switched to standard vacuum brakes and for a long time all seemed OK. Every once in awhile as of late when I first get in the car and start it the brakes are hard as a rock or mushy. After I put the car into gear and start moving at idle the pedal normalizes. What gives? This does not happen all the time and I see no leaks or cracked vacuum hoses.
 
About a year ago I had my system switched to standard vacuum brakes and for a long time all seemed OK. Every once in awhile as of late when I first get in the car and start it the brakes are hard as a rock or mushy. After I put the car into gear and start moving at idle the pedal normalizes. What gives? This does not happen all the time and I see no leaks or cracked vacuum hoses.

Start by replacing the plastic check valve on the booster.
 
I just pulled it and there was a lot of vacuum behind it. Used the vacuum gauge off the line itself and got 19" of vacuum . Tried new check valve, no difference. Is it possible to have an air bubble in the system and if so how would I clear it? Bleed the brakes?? Want to try anything before tearing the system down and replacing the booster which is the dual Cardone unit.
 
Last edited:
What do braided SS brake lines go for? I was thinking one of mine may have collapsed internally.
 
Last edited:
Now I have a rock hard pedal and the idle is off. When the pedal is depressed at idle the idle goes up then levels off. No more bleed down at start up either so it looks like both diaphrams are bad. Not a happy camper! Set up is just barely a year old.
 
Just had the booster (Cardone) replaced. Half way home the front brakes locked up solid. What gives?
 
I don't think the booster is going to cause your fronts to lock. Sounds like a MC issue
 
Top