I put new rear brake likes (the long one from front to back and the two short ones in the back) earlier this year because i was getting pissy that i was always having to bleed the brakes. The brakes have never ever been right on this car. I cant seem to get them perfect. Always having to add fluid and bleed the brakes. Always is on the front cup in the MC which is for the back brakes. No apparent leaks anywhere, an ALL the hydralics are new. It does appear to be coming out the top of the MC. So there must be something making it blow the fluid around in the MC and making it leak down the side (thus ruining the paint beneath it). I have replaced the MC twice. I did bench bleed it. The brakes always seem fine, but slowly but surly somehow air gets in. and over the course of a few months the pedal slowly gets to where it has to go down farther, and then a lil farther and then a lil farther, and if i dont put fluid in it it will eventually end up on the floor and have to be pumped up. The only way to fix it good, is to rebleed it then its good for a few more months. Im TIRED of doing that tho. I want to be done with brakes. Could the prop valve cause me a problem even tho there is no leak there? Or is the MC bad? or am i not getting all the air out? I think i used a one man brake bleeder to bleed the MC and then stuck it up there and hooked it up. Maybe it got more air in it then? But then wouldnt it eventually work its way to the back and get bled out there? Or maybe its just the one man bleeder that is the problem. I didnt use a one man bleeder on the 79, and its brakes seem good but then again, i havnt driven it but once because im still working on it. Anyone got any ideas?
Hello pintoguy76,
Most likely a bad wheel cylinder.
Pull the rear wheels and look at the backside of the rim I'm sure you will find the problem. The leaky wheel will have lots of greazy powder on the wheel.
I do not know what to tell you about the master C BUT,
when the brakes are released and the rear springs pull the shoes back it may be introducing air back bled into the system.
Kinda like squeezing ketchup from a bottle and needing a 2nd squirt you have to let air back in so you can get more ketchup out...
OK Most who know me will say... YUP that's how Pintony talks!!!! ;D
From Analogy 101
PintoGuy76,
I would do what Pintony says and look for a leak. It does sound like a slow leak (a couple of months). Air can't get in anywhere that fluid is not getting out. Air generally does not work it's way anywhere but to the highest point it can collect in the circuit if you originally did not get all the air out. I would make a thorough check for leakage and then manually bleed them really good to make sure there is no air. Also, I can't understand why fluid would be comming out of the mc cover. That's no good.
High_Horse
The wheel cylinders are new. Ive even checked on them all a few times, there are no signs of leaks anywhere. Even under the drum. I think the leakage is all thru the master cylinder, and that the fluid is somehow all being squirted around and leaking out the top. That'd explain why the MC is always wet and why it takes so long for it to mess up. Tho the pedal does seem to get worse slowly also and i cant see that happening from the MC unless the MC runs dry. Maybe it has i dont know, i know ive caught it low a few times. Really low. I am really irritated, because i went thru the trouble and expense of replacing the brake lines, (hard lines and rubber) all the way from the front to the back and to the wheels, which dont fit worth sh*t, and i still havnt fixed the problem. I think that somehow, i just havnt got all the air out and that the problem is the stinkin one man bleeder. The only way to know i guess would be to try bleeding it all again with a helper this time and not a one man thing, MC and all 4 corners, and then waiting to see what happens. The way i did it on the 79 was i bolted the MC on, filled it with fluid, pumped the brakes a few times, then had a friend hold the pedal to the floor while i unscrewed each line a part of a turn to get the air out, then closing it and re pumping. eventually it stopped bubbling when i unscrewed the line. I assme this got all the air out and since i retightened the nuts before i had him let up on the pedal all the air should be out. I then id all 4 wheels and i tell ya that pedal in that thing feels awesome. As it should. The pedal in the 76 never has been quite perfect, which leads me to beleive there has been some air in it all along. So i really dont know. I will check on the wheel cylinders again, id like to check for posi, and i need to rebleed the brakes anyways, so ill give it all a once over again. Thanks for the replys, guys.
PintoGuy76,
Refurb masters are iffy. I have heard of guys buying 3-4 of them before getting a good one. Also, if you have power brakes, you may be losing the fluid into the booster and not see any sign of it. I'll bet that your new master is the problem.
WagonNut.
This is the 2nd one and ive been on it for a while but its never been right. I guess when i get some extra money ill just buy a totally new one. Its like $50. Not too bad.
PintoGuy76,
Here is a longshot. Maybe your Booster Pushrod Projection is not correct. The correct way to set up a master cylinder is to have the actuator cups just behind the inlet holes. You don't want the cups to far back otherwise there could be a fierce streem of fluid injected into the rezes each time you apply the brakes ( that might be the turbulation you mention that is blowing past the rez cover). Maybe your booster rod is to far back and needs extended. The A- dimension in the picture is .941-.956. Did you adjust that bugger? Maybe it is to far forward? Check under the dash and see if you have any fluid comming out where the rod goes into the boot.
High_Horse
The car has manual brakes. I havnt seen any fluid inside the car but then again i havnt removed the boot to see if theres anything behind it or not...