i just did a rear disc swap on my std with 40/40 valve but now the pedal gets hard when the car is off, but when the car is started it travels almost near the floor. I bled the brakes about 3 times to make sure there was no air. car stops on a dime when the car is moving, but if I like sit at idle I can push the pedal down bout to the floor.

i was thinking maybe since the std stock master cylinder was so small it might be affecting it, but i dunno. the master cylinder is less than a year old so it cant be worn.

any suggestions?

 

A bad master cylinder is a distinct possiblity, it may be leaking into the brake booster where you can't see the leak (or your old one may have, and fluid killed the booster). A sure fire way to tell is that the bottom of the brake booster will be rusty. If the master cylinder has leaked into the brake booster, replace it too, because brake fluid will dissolve the diaphragm (a bad diaphragm in the booster will definitely cause the brake pedal to drop when the engine is running). Does the red brake warning light in the gauge cluster light up after a few weeks of driving?

If you need a new brake booster and master cylinder combo, get one from a non - abs 2nd gen integra, it will bolt right up and the master cylinder has a larger bore than a stock civic one.

 

well see the thing is, the brakes worked fine before the swap so im pretty sure the ms and bb is fine, but you never know i guess. I'd just hate to spend $200 if thats not it...

 

more than likely you ruined the master cylinder when you bled the brake fluid, how did you bleed the brakes?

 

you need a bigger MC. get a 15/16 civic EX or prelude one.

and its a 4040 proportioning valve. not a 40/40.

 

i did it with a vaccuum and with the pedal, but i made sure not to have the pedal hit the bottom real hard.

 

ok, thats the best way of doing it...being that you replaced the prop valve, you may have air in the system still. :shrugs:

 

i guess i'll try bleeding again, i used a couple different sequences because I have heard 4 different ones, could this mean I may have just chased bubbles around instead of getting rid of them? i did RR LR RF LF

 

go get a BB and 15/16 MC...i just swapped them two weekends ago and had the same problem...i bled everything, but still all the way to the floor...just get a MC and BB to be safe, and trust me its worth the money

 

Even better swap a 94-01 Teg w/ ABS booster, and MC. It will be good for future mods, when you put larger brakes on.

 

make sure u tightened the bleeder screws on teh front and rear calipers. u may be gettin air through them.

 

did you make sure to put something under the brake pedal when you bled it, so the pedal didnt go too far? if you dont, the little piston thingy will go in farther than it used to, and there could be rust/corrosion on it, which could have damaged the diaphragm.

 

master cylinder is pretty much brand new, and wasnt a reman. the bleeder screws are very tight. maybe i'll just get the bb and ms. would you recomend the 15/16 or the 7/8? i dont want the pedal to be too hard.

 

15/16 is best and its not too hard...thats what a brake booster does, it makes it eaier to push

and it doesnt matter if the MC is new it is not made to support that Prop valve...mine was only 3 months old before i swapped it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by atmdc &raquo;</TD></TR><TR><TD CLASS="quote">i guess i'll try bleeding again, i used a couple different sequences because I have heard 4 different ones, could this mean I may have just chased bubbles around instead of getting rid of them? i did RR LR RF LF</TD></TR></TABLE>I would like you guys to confirm this "RR, LR, RF, LF". Is this the right sequence to bleed the lines?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by atmdc &raquo;</TD></TR><TR><TD CLASS="quote">master cylinder is pretty much brand new, and wasnt a reman. the bleeder screws are very tight. maybe i'll just get the bb and ms. would you recomend the 15/16 or the 7/8? i dont want the pedal to be too hard.</TD></TR></TABLE>

1" FTW, but I am running 11.1" front brakes, with Accord wagon calipers.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CW-ITR &raquo;</TD></TR><TR><TD CLASS="quote">I would like you guys to confirm this "RR, LR, RF, LF". Is this the right sequence to bleed the lines?</TD></TR></TABLE> yes...easiet way to remember is furthest from MC and then 2nd furthest...and so on

just to make sure...passanger rear - driver rear - passanger front - driver's front

 

 

looked over some stuff today and noticed that the brake resevoir was only half full but it was full before, so I looked at the prop valve and its leaking when I hit the brakes from the little rubber button thing on the front. and one of the lines are bubbling.

ok now my question is when I get a new one, can I put plumbers tape or something on the threads?

 

try to pull the hardline adn get a new one, i wouldnt put all my faith in "plumbers tape"... but if you cannot find anything that may do the trick. Also check to make sure you put the threads in correctly, i thought mine were in, but truthfully i had to pull two and bend the lines to make them fit flush...

 

does it sound right for the valve being busted making my pedal do this?

 

Yes absolutely. Any leak will diminish pedal pressure. Fix the leak, and you should be good. You don't need a new MC, until you upgrade the front brakes. CRX Si's came with rear disc, and they came with the same MC as drum equipped cars.