ok here we go.....replaced master cylinder power booster both front calipers pads rotors both wheel cylinders shoes springs everything except the lines going to each wheel and the prop valve.....everytime the car warms up the front brakes clamp down like the fluid is expanding but if i let the car cool off for a couple hours its fine till it warms back up.....ive bled and bled and bled and im out of ideas so anything will help.....thanks in advance

 

I would guess prop valve. something similar happen to my bros ek, it would happen at weird time, and once i replace the pro valve for him, it stopped.

 

well i'm going to replace the front lines tomorrow and see what happened i doubt that fixes it but the prop valve is next

 

bump

 

up

 

Hows the pedal feel when it gets hot?

Have you replaced the plastic valve on the hose that goes from the booster to the IM?

 

What booster did u use? Are you sure the pushrod isnt adjusted out to far?

 

well i backed off the brake light switch and that has seemed to fix it so i'll keep you updated

 

hey man i know what is wrong with your car i had the same problem you need to check the clearance between the master cylinder and brake booster if you are not sure what i am talking about feel free to contact me and i will explain easier on the phone

 

 

I just bought an 89' Si with a B16. Flew from Idaho to AZ to pick it up. Changed the pads, rotors, front drivers line & caliper and master cylinder. Didn't fix the problem and I couldn't find an OEM prop. valve so I got one of a salvaged car. It seemed to fix the problem. Got 600 miles into my 1000 mile trip and they started grabbing again. Every time I let them cool down I'd get back on the freeway and they'd lock up again.

Finally I disconnected the vacuum hose from the booster and stuffed the hose with a stick and a plastic bag. I didn't have boosted brakes but it got me the rest of the way home without locking up. Any suggestions on what else it could be? I've also noticed my brake lights stay on a lot, like the pedal is out of adjustment.

 

if youv ever replaced a booster. its probably the pedal adjustment

 

had the same problem once. i had the calipers on the wrong sides. yes it is possible! make sure the valve on the caliper is pointing up if i remember correctly lol