how do you know when your brake booster is going bad?

 

Well, when my Master was going bad it was dumping fluid into the booster, so it was eating fluid while at the same time making my brakes mooshy. Not sure what happens when the booster goes completely. Brakes get really hard?

 

i just replaced my master cylinder yesterday and i suspect that my booster is now toast because i got a lot of brake fluid in it. aside from my brake peddle not fading anymore, i still dont have much of a pedal. a sure way to tell if your booster is good is to push the brake while your car is off, and then turn it on with pressure still on the peddle. you should feel the peddle sink a little. if it doesnt sink or just stays the same, your booster is bad. i will be replacing my booster some time this week i think.. i might do a write up of it.. but it shouldnt be too hard to do anyway.


Modified by sanimalp at 11:34 AM 6/26/2005

 

From the DA helms manual....

Function test:
with car off press pedal hard for 15 sec. If the pedal sinks the mc, brake line, or wheel cylinder is bad.

hold the brake pedal and start the car, the pedal should drop slightly. If it doesn't drop the booster or check valve is faulty.

Leak test:
with the car running press and hold the pedal, turn the car off, if the pedal pressure stays constant for 30 seconds the booster is good. If pedal rises, the booster is bad.

with car off press the pedal normally several times, pressure should rise. If it doesn't look at the check valve.

check valve test:
disconnect the hose from the booster, vacuum should be available.

 

i just changed my booster in my new 88 si, it was leaking air.... so not only were the brakes not powered at all, but i had a bad vac leak too

 

is there a way to change the booster without having to bleed the brakes? cause ive bled them about 4 times for various reasons and i am sick of it. or will i have to do it one more time..

 

yeah...I just replaced my master and booster and my wheel cylinders...you need to bleed it quit a bit, well that was the experience with me at least. And another thing, just might want to check out the master and wheel cylinders if the booster is bad because in my case it's a domino effect, if one goes bad the others tend to go bad with it. I'm not a brake expert though so just my 2 cents

 

There is no need to bleed the brakes when changing a brake booster.

If your pedal is high and hard, its your brake booster

Low and soft, your master cylinder

 

How hard is it to change the brake booster? Are there any known OEM upgrades? I've heard of people using prelude MC's on CRX's...is there anything like that for the BB?

 

^^ sure, people use integra boosters all the time. its not too hard to replace, but you have to pull your dash to get to the 4 bolts holding the booster on. good luck

 

Yeah, people use integra (non-abs) MC's and boosters that flow a lot more fluid and are more compatible with the bigger teggy calipers and rear disc brakes. Generally they're about the same price so you're better off getting the teg setup so if you do rear disc in the future you already have one of the main parts. All you'd then need is the proportioning valve and all the other brake parts.

 

should note, to use the teg master or booster you need both. the MC flange is different than crx's