I have a DA '90 with abs and i did a Ls brake conversion. when i drove the car the brakes locked on me. this happens constantly, its drivable for awhile then it starts to lock again. does anybody know how to fix this problem?? please help

 

Can I get some specifics please? What does it exactly do? If you hit the brakes it locks? Or what? You're just driving along and all of a sudden your brakes engage and you fly forward out your windshield cuz you're not wearing a seatbelt or what?

 

first of all yea i was wearing a seat belt second i wouldnt be here posting if i flew out the window anyway when i drive the car for a couple a blocks it slowly starts locking up until the car completely stops. I have to leave the car sitting there for a couple of hours until it unlocks on its own.

 

its the brake booster had the same problem

 

i'll look into that thanks

 

are the rotors possibly too big. caliper lock up? what do you think is defectdive in the brake booster since u say its the problem?

 

+1 on replacing the brake booster. I have seen this happen many times before, especially on DA's with ABS delete....

I must warn you, the top bolt of the booster is a pain to get to! You will need alot of patience for this one!

 

A power booster uses atmospheric pressure to help assist the pushing of the master cylinder piston. Basically, a power booster is divided into two chambers internally with a rubber diaphragm seperating each. With no force applied to the booster there will be vacuum on both sides of the diaphragm. This vacuum is supplied by the engine either from the intake manifold or the back of the carburetor.

When you press on the pedal, the rod opens a poppit valve in the booster that allows atmospheric pressure on the firewall side of the diaphragm. This causes the diaphragm to push on the master cylinder piston thru a plastic hub, providing power assist to the master cylinder.

There must be a problem with the poppit valve or the rubber diaphragm and is creating pressure to the master cyl, therefore causing the Brakes to lock up without pushing the pedal...

That what this car was delivered to me for, shorly after her ex-husband did an ABS delete...

 

i had similar problems and mine ended up being the actual abs unit itself

 

if it locks up on you again, just have a 10mm wrench handy and break the line open into a rag. The fluid will be hot, but this will release the pressure and open the calipers back up allowing you to inch your way to safety!

 

deff not brake rotors ud be experiencing brake fade and u wouldnt even make it out the driveway +on the brake booster

 

lol