Brake puzzler?

[zachmac]

So, I've pretty much gone through the brakes and a full rebuild of the front suspension (new loaded A arms, IAP springs, yellow Konis front and rear, inner and outer tie rods and center link). I put on rebuilt front and rear calipers and changed out all of the brake hoses for braided lines. Went with upgrade front rotors from Allison along with green pads in front (new OEM pads in back).

Here is the problem: the brakes will work great for a while with no pull to either side and nice even strong stops. THEN, over a very short time / miles the pedal will start to go mushy and the car will begin to pull to one side or another. I pull all the wheels and re-bleed and lo and behold I have a lot of air in the rear brakes (mostly driver side but in both). Yes I have the compensator rod such that it isn't closing off the circuit and I re-bleed until I have solid fluid and put it all back together. Works great for a while and then, repeat!

BTW, no apparent loss of fluid anywhere between good and bad? Is air entering the system of do I just have to keep doing this over and over until I REALLY get all the air out? I think counting the initial bleed I am up to three or four cycles.

Also, I know a couple of options exist for upgrading the front brakes but is there any rear brake option? I now have 15" Rotas so I can fit bigger rotors.

[Foster48x]

Jeff, you didn't mention your master cylinder. Did you replace it also?
Rick

[zachmac]

Jeff, you didn't mention your master cylinder. Did you replace it also?
Rick

No, I haven't touched it or the booster. I know they could be the problem, BUT, the brakes worked fine before I started any of this work and again, I haven't touched the master or booster. In my experience when you "fix" a perfectly good system and then it acts up it is something you "fixed", not an unrelated failure. I re-bled yesterday and so far so good?

[Foster48x]

Just thought I'd throw that out there for you to consider. I never could get all of the air out of my old master cylinder after replacing and rebuilding the rest of my brake system. I think the seals and nipples to the reservoir were just shot so I replaced it and haven't had any problems since.

Good luck.
Rick