so now i think my master cylinder is trashed....completely unrelated to the accident i had with the accent.

symptoms started after working on it, the brake pedal was far too soft. the more i press it it slowly gets closer to the floor until its nearly there. oddly, the brakes DO grab well enough to drive....but i have to get this fixed. i start a new job in less than 2 weeks and i have to drive a lot to get there.

here's what i found:

tried bleeding all brakes to start. didn't change a thing.

discovered that i was getting a good deal of air out of the front left. bleeding it did not help. later discovered that more air is getting in somehow....i bleed it, seems ok but wait and then a big pile of small bubbles pour out. top off the reservoir and it'll start happening again.

obviously air is getting in somehow, but only appears to happen with the front left brake. i started with replacing the rubber hose, i figured it was somehow damaged. then i replaced the brake caliper and the metal line.

SO NOTHING IS LEFT BUT THE MASTER CYLINDER!!!

doesn't make a lot of sense....can anyone confirm or think of anything else? oh and there are no leaks....

 

Yes, that sounds like a bad master cylinder.

 

thanks nova. its just so bizzare that this will only happen in one brake and presents in a big stream of little bubbles only when i fill the reservoir....maybe its repairable, but i doubt it. guess i order a new MC today! completely unrelated to a minor accident i had recently....go figure that one.

 

It's usually an internal leak inside the master. I had it happen to my Nova many years ago.

 

I had that happen one in my xr4ti. it turned out to be a bad seal on the caliper piston, or the lack there of. If the master cylinder is leaking you may find fluid in the vacum booster.

 

well its certainly not the caliper, as i have already stated, has been replaced. i'll take a look for a fluid leak behind the master - i pulled it out last night in the dark.

thing is i am not losing fluid except when bleeding - pretty normal i'd say. its as if its sucking in air somewhere and only when the reservoir is filled.

 

I said an internal leak. Meaning when you pump the brake, instead of pushing the fluid down the lines, it's leaking back into the reservoir. That's why the pedal goes to the floor slowly.

 

thats my thought too. the odd part is that it continually takes in air, won't leak fluid and that air always seems to go to the front left brake system. theres no way there can be a leak in that part of the brakes, everything has been replaced. new steel line, new rubber hose and a new caliper. wtf

 

well i've had it. i replaced the caliper, hose, metal line and now the master cylinder. its still getting air in it. this makes no goddamn sense. i can now also get some air out of the front right in the same manner, but not as much and takes longer. cant get jack all out of the rears.

i've had it, the car is going to a shop.