Hi, About a couple of months ago I left without brakes when the front driver's side hose was teared. So, I replaced it and since i took the caliper off i decided to change the seals and to paint both calipers. When I reinstalled the calipers I naturally bleed them and that's when the problems started. The brake pedal went down to the bottom and didn't went firm again. So, I thought it was probably the gaskets of the master cylinder (though the car braked perfectly before the teared hose), long story short I couldn't find them so I bought a new (reconstructed) master cylinder and installed it, and did the initial bleed on the cylinder and then on the brakes. At first it seemed to work, I thought I'd nailed it, but then today (my first run after the "repair") going from the shop to my home the brake pedal was firm but as I kept pressing it down it began slowly to go to the bottom, I gave a few pumps and it regained firmness but as I kept it pressed it went down. It felt as if was losing pressure just as the old cylinder (which was the main reason for me to change it). As I was getting close to my home the pedal lost all firmness and went completely loose, i went into panic an smashed the pedal almost to the radiator and the car stopped squeeking wheels, it was then that I noticed that if I floored the pedal the car braked althought I think it's the rear wheels that braked. I'm out of ideas on what to do, just a couple of hours ago It came to me that maybe the pedal isn't working well or that it maybe needs adjustment to work with the master cylinder, since it's not exactly identical to the old one. Please I would REALLY appreciate your expertise I don't want to be scared of driving the car because of fear of going out of brakes!!! HELP!!!
the reconstructed master cylinder is most likely bad. if when your bleeding the brakes, you get fluid coming out of all the brakes then you know that you dont have any blockage. when you painted the calipers i hope you didnt paint the pads or the rotors. paint will make the pads and rotor just slide and not stop the car.
I took the caliper out of the car and disassembled it to paint it, so no paint on the rotors or pads. When i bleeded the brakes i got fluid from all corners. But i testedthe cylinder by putting plugs on both circuits and it didn't lose pressure. Could it be the brake proportioning valve?
Sorry, but I have to ask: How are you bleeding them? I always get the wife to pump the pedal and hold it. Then I open the bleeder screw for a few seconds, then quickly close it. Then repeat all of this a couple of times until you get a steady stream of fluid with no foam or bubbles. Keep doing this for each wheel. I bleed them in the following order RR, LR, RF, LF. I did mine this fall after replacing all cylinders including the master and my pedal is rock hard and if I jump on the brakes in too much of a hurry, faces are kissing cracked dash pad!! If you're bleeding them by yourself (by gravity) then you probably don't have all the air out. How different were your old and new Master Cylinders? Have you noticed any fluid loss? If so, pull the rubber boot off the back of the master cylinder form inside the car and see if there is any fluid leaking from where the pushrod goes into the Master Cylinder. Keep us informed as to what you find, and Good Luck!
if the brake pedal is fading then it almost seams you have a leak some where is the back side of any of the tires wet with fluid
Sounds like what I had awhile back. If I hit the brake pedal very quickly, everything worked as normal. If I just put them on lightly, the pedal would go almost to the floor! Sitting at a stop light, it would slowly ease down also. Those who suggested to replace the master cylinder are correct. Don't get a " rebuilt " one ( they are junk ), you need a new one from a reputable supplier! I prefer Napa for my parts! Others here may have suggestions also. Just make sure it's a new part made in the U.S.A.!
First of all thanks for your quick responses, that's what I love about this forum, so much friends willing to help! Second of all, sorry for taking too long to post again, I had a very busy day yesterday And I couldn't find time to get near my tablet. Now to business, I bleed the brakes both manually and by gravity, and I didn't see foam or bubbles. It's not that I can't be wrong but I've done this hundreds of times. The cylinders are close to resemblance the biggest difference is that the holes on the side where the lines connect are different size, I just cut the line and put the nuts that fit in. At night I checked the cylinder and the large hole was empty (the front brakes circuit as far as I know) which led me to think that I'm having a leak on the front brakes, still I didn't see It, I checked both wheels and they're dry, and followed the lines and saw nothing. Any ideas? Or maybe I was clumsy enough to not fill the cylinder after the bleeding?
When the pedal falls away when its pressed, either there is a leak (you should see fluid by now) or fluid is leaking past the rubber in the master cyl. Think you need to replace the master cylinder.
Is your larger reservoir at the front or rear and do you have power brakes? If the larger reservoir is at the rear and no power brakes look at the rear of the cylinder ( inside the car at the rubber boot ) and see if fluid is leaking down under the carpet. Also look at the rear of the cylinder where it mounts on the firewall ( under the hood ) for a leak down the firewall. If you have power brakes, take the cylinder loose at the booster, slide it out a half inch or so ( no need to unhook the lines ), and see if fluid is leaking out of the rear of the cylinder. The fluid has to be going somewhere!
Did you bleed the proportioning valve when you installed the new cylinder? I forgot to do that when I put in my new master last month. Quite annoying to have occasionally squishy brakes.
I don't have a booster, if that's what you mean by power brakes, but I have front disc brakes, except that they're different from what I've seen so far here on the forum. They look like falcon disc brakes. I have yet to check for leaks, but that's a good tip to look for them inside the car and on the back of the cylinder, thx!:Handshake
