paulbosman

I have some questions about my combination valve.

I have a 1988 Z28 with front disc and rear drums. I recently bleeded the system and noticed that when i push my brakepedal down the fluid spids up inside the resevoir from both of the connection points. The brake presure is fine (not great).

Is this normal or do i have to change my combination valve.

greetz.. Paul

camaronewbie

it's normal

cjh1505

you said that it is normal for fluid to come out of both ports...is it ok if it just come out of the one closer to the firewall? i have a 86 iroc with disc drum brakes. i am having brake problems and trying to explore every different problem. thank you.

camaronewbie

All I know for sure is, if the lid is off the resevoir, and yo mash the pedal, the fluid is going to squirt out and make a mess (always leave the lid on when bleeding).

If you have a soft pedal, first I'd bleed bleed bleed. Start at the rear pass, then rear dr, then frt pass, then frt dr side (work from farthest away to closest).

Then, I'd bleed again.

Then, (can you guess?)

If you've bleed the brakes until you just can't stand the idea of seeing another drop of brake fluid, and you still have a soft pedal...

Next step is replacing the flexible brake lines on each wheel (well, there are only 3, the pass side rear doesn't have one. These wear over time, the rubber becomes soft allowing it to balloon (bulge) instead of maintaining the same size and passing the fluid pressure to the caliper/cylinder. They are pretty cheap, maybe $12 each. And they rarely get replaced. But guess what - you'll have to bleed all over again.

If that doesn't help, then I'd look into new rear brake cylinders - again a cheap fix at about $15 a piece.

I personally think it's pretty rare that a m/c or proportioning valve ever goes bad - in my 30 years of fixing my own families cars, I've only ever replaced 1 m/c and never a prop valve or vacuum booster unit. 9 times out of 10, if the bleeding doesn't fix it, the flex line replacement does.

cjh1505

thanks newbie.well i can say that i bleed every brake 3 times already before i ever posted this.i installed hawk pads on slotted rotors in the front with little change in the feel. i was thinking about changing the lines with some braided ones. but when i stuck my head under my car a quick look a thought popped to mind. maybe these stock brakes are way too small. for a joke i measured the width across of the caliper at approx 4 and half inches. now here is the funny part. i also own a 2001 nissan sentra which is my work/everyday car.this car wieghts about 1000 pounds less than my iroc and the caliper measures 4 inches across. there is something majorly wrong there.
i know the pad rotor combo works really good. i had the same set-up on a 2001 monte carlo ss.when u hit the brakes it was like droping an anchor.
after all of this reseach i might just upgreat to a set of wilwood or bear brakes. but for sure i will add the new lines no matter what i decide.