I recently did a lot of brake work to my 92 plymouth voyager (134k miles). New cylinders in back, new shoes, and new pads up front. The initial reason for the work was because I was almost down to the metal on the fronts, and there was noise coming from the back right. A lot of things were worn out so I changed the obvious parts. I ended up bleeding the lines replacing the (green) brake fluid, which worked well. The brakes still felt spongy, but were better than they had been.
Yesterday, my brakes failed after about a week of working properly. No fluid in the reservoir.
During the initial repair, while compressing the front right cylinder back into the caliper, I heard what sounded like liquid spashing in the area of the master cylinder. I assumed that I had overflowed the reservoir, but when I checked, it wasn't full.
(as a tangent, I know you're supposed to open the bleeder valve when pushing the cylinder back, but at that point, I was hoping to avoid a bleed, and the manual didn't say to do it, and I had gotten away with it half a dozen times before)
I was worried that I had broken a line or something else, but as I said, everything worked properly and there were no obvious leaks in the system after replacing the one cylinder in back. There was acceptable pedal pressure and it worked fine for a week or so.
Obviously, there is a leak now. I'm assuming that the leak is not at one of the wheels, becuase I would have only lost one circuit, right? If that's true, that leaves the master cylinder, and possibly abs parts I'm not very familiar with. The repair manual says to relieve the pressure in the abs system by pressing the pedal 40 times or so before bleeding, which I did.
Can anyone suggest a place to look for the leak? I'm sort of leaning toward a bad master cylinder. Where would the brake fluid likely go of this were the case?
Also, I initially tried the bleed with a hand pump, but got bad results. I resorted to the two person method. This told me that the hand pump worked, but the pump sucks so much air around the fitting that it's hard to know if the air is coming from the lines or not. This was after putting grease on the fittings. I'd like to use one of those presurized systems that screw into the top of the master cylinder. Are these safe with my abs system? I'm getting mixed answers.
brian