This has me super stumped. When I first get in to drive my car, the brake pedal feels normal. Maybe after 5 mins of driving, the pedal gets a little harder and has less travel. After about 10-15 mins of driving, the pedal is rock hard as if the booster lost vacuum. Then the brakes start to drag. If I let the car sit for and hour or so, the problem goes away. Then once you start driving again, the whole ordeal repeats itself again. I've put 2 different boosters and 2 different master cylinders on it. All of the brakes drag, not just a pair. Anybody have any ideas, what might cause this? Thanks in advance, for any help.

 

it sounds like a problem i had with my crx all i had to do was change the master cylinder. Do you smell the pads burning. maybe the piston the cap. are sticking closed when they get heated up

 

booster check valve, maybe

 

contamination of the brake system like if some one puts ps fluid or oil or coolent into the brakeing system it will swell the seals and make the brakes stay on. And whe the fuid gets hot it expands more.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MONSTERZC &raquo;</TD></TR><TR><TD CLASS="quote">it sounds like a problem i had with my crx all i had to do was change the master cylinder. Do you smell the pads burning. maybe the piston the cap. are sticking closed when they get heated up</TD></TR></TABLE>

I'm on my second master cylinder and second brake booster. Been getting the remanufactured stuff. Thinking about going to get an oem setup.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by postman &raquo;</TD></TR><TR><TD CLASS="quote">booster check valve, maybe</TD></TR></TABLE>

Checked that already. When the problem was occuring, I pulled the vacuum to the booster and it was fine.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rainforest &raquo;</TD></TR><TR><TD CLASS="quote">contamination of the brake system like if some one puts ps fluid or oil or coolent into the brakeing system it will swell the seals and make the brakes stay on. And whe the fuid gets hot it expands more.</TD></TR></TABLE>

Are you saying to try flushing the system? If so, I'm on like my 4th one.

Thanks for all the help so far guys.

 

When you replaced the MC, did you measure the pushrod length (compare against old MC)? When you release the brake pedal, the MC must be at just the right position, so the vent is open back to the reservoir. If not, then the system will pressurize itself as it gets hot.

You can check this by pushing a piston back into it's caliper, which SHOULD push fluid back into the reservoir. Trouble is, I don't know about checking this with it HOT. Maybe you can get them hot, then use something to pry the calipers over, compressing the piston that way??

 

Figured it out. Didn't know that there were two adjustments on the brake booster. Had only adjusted the clevis. Thanks.