Master cylinder drama

[EGB16A]

Today i got my new master cylinder installed, because my my old one gave up the ghost!
I got a prelude master cylinder, and brake booster installed, along with some new braded lines. (while i was there i got engine and gear oil changed too, if it makes any difference)

After leaving the mechanic, everything was fine, braking was firm and responsive, but i was still taking it easy for a while just to let things settle.

On my way home from my g/f house later on, braking seemed normal for a while, then the pedal became firmer, and firmer.

I went for a spirtited drive around my area (still going easy on the brakes of course), and by the time i pulled into my drive way i didn't need to put my foot on the brake, because the the car was stopping on it's own! :(

It feels like the brakes are siezed, and the pedal feels like when you pump the pedal a few times while the car is off, ie really hard....

Any help guys? Is there anything i can try before i got to work in the morning so i can drive my car?

other wise i'll have to take it to the mechanic tomorrow somehow

regards
Lloyd

[ECU-MAN]

sounds like the booster is playing up or the proportioning valves are not working properly.



Im guessing you put Prelude BMC and booster in a civic. that might not be a good Idea

[bennjamin]

check all the lines ~ perhaps the vaccum line is loose / not capable of keeping the prelude BMC up to power ? (id assume that the normal civic would produce enough grunt to keep it pressurized?)

[blusir2]

they may not have tightened the locking nut that holds the piston in place for the master cylinder.. there is a adjustment under the dash behind the brake pedal...

after i bled my brakes i adjusted my one a bit on the civic and it braked very well and firm.. but then it started to get like how u described.. firmer and firmer and firmer... till the brakes were smoking up due to the pads burning up..

i just stopped the car and un-did the locking nut and un-screwed the piston out a little so that it wasnt compressing the master cylinder as much... then it was all sweet... becoz u changed the brakes the system needs time to alter to the new setting and get to neutral... the mechanic must have thought the pedal was too soft so he wound in the piston, that i was talking about, where the brake pedal pushes onto... its a booster..

hope ur problem is all fixed now...

keep posting if u need more info

Jason
TODA Racing Australia

[EGB16A]

sounds like the booster is playing up or the proportioning valves are not working properly.



Im guessing you put Prelude BMC and booster in a civic. that might not be a good Idea

yeah i did, how come this isn't a good idea?

[ECU-MAN]

because the master cylinders are different, the prelude ones have different bore/piston diameter so you get diffent pressures when you brake. this could cause lock up, it is best to change the calippers and proportioning valves to suit.

aslo if its a ABS master cylinder more bad news.

[EGB16A]

All issues SORTED!!!

braking is excellent now. far better than the civic master cylinder/booster

[ACTI0NMAN-1]

what was the cause, then close the thread please

[EGB16A]

what was the cause, then close the thread please

jason was correct, and y close the thread?

[EGB16A]

because the master cylinders are different, the prelude ones have different bore/piston diameter so you get diffent pressures when you brake. this could cause lock up, it is best to change the calippers and proportioning valves to suit.

aslo if its a ABS master cylinder more bad news.

I've done afew little tests, and i think the civic MC/booster locked up a whole lot easier the the prelude.
Thats just personal experience so far. I'm yet to drive in the wet, but its raining now, might go for a drive lol :D

[OzSir2]

I'm having a similar smoking brake problem now. However I have only had new rotors and pads (to suit civic) replaced on my civic perhaps 1000km ago. Only the left rear brake is smoking up. Do you suggest the same...as in adjusting the bolt behind the brake pedal to fix this problem...or is there some adjustment I should make on in the viciinity of the brake itself...If yes where exactly is it?

[ECU-MAN]

you might have a seized caliper or hand brake cable

adjusting your pedal wont do any good at all

[blusir2]

I'm having a similar smoking brake problem now. However I have only had new rotors and pads (to suit civic) replaced on my civic perhaps 1000km ago. Only the left rear brake is smoking up. Do you suggest the same...as in adjusting the bolt behind the brake pedal to fix this problem...or is there some adjustment I should make on in the viciinity of the brake itself...If yes where exactly is it?

wat ECU-Man said is correct. ur fault wun be the adjusment for the booster. Sounds more like the imbalance of the handbrake cable. They mustnt have fine tuned the cable adjustment on the handbrake.
Unscrew the cover over the handbrake by lifting the little cover pad below the handbrake handle. lift it up with a flat head screw driver and undo the 2 phillips head screws under it. Then undo the screws from inside the armrest box if u have one. Remove the cover for the hand brake handle and u shall see 2 cables connecnted onto a T shaped bar connected to the handbrake handle. These 2 cables are the cables connected to ur rear brakes. There will be 2 adjusters, one for each cable ( i think its a 10mm spanner). CounterClockwise turns will loosen the nut and therefore put less tension on the cable and u'll have to lift the handbrake handle higher to have the rear brakes locked.
I think ur prob should be here. They may not have adjusted both exactly right that is why only the left is smoking. So u should loosen the nut that is connected to the left rear brake cable and it should do the trick. If not then the problem should be in the adjustment on the rear caliper itself which is more of a hassle.
Try that first. Hope that helps. Good luck.