Recurring spongy pedal 4000 Quattro
 

After getting the car back on the road I had a low brake pedal so I pressure bled the whole system. I probably did not do the bleeding in the right order but I found air in the last wheel bled, the right rear. The pedal was fine for about 100 miles and has gotten soft again so I did the RR again and found air again. I am ordering a new set of brake hoses as it seems like a good place to start, I wanted to change them anyway as they are the original lines but does anyone have any other thoughts?

Hey folks, after doing a bit of reading I believe that air can leak in thru the piston seal in the caliper so I have purchased a rebuild kit and when I install the new brake line I will also do the caliper rebuild, parts due next week

Folks, I have not gotten to rebuilding the rear caliper as the spring on the caliper for the E brake scares me. Does anyone know how to remove this spring from the caliper and more importantly how to reinstall it, it looks like it would be really hard to reinstall without releasing the ebrake tension, advice appreciated, thanks in advance

Hello folks, well here it is 18 months later and I still have not moved on. The pedal was getting lower and lower within the last few days so I pressure bled the right rear again and all is good. I never figured out how to remove that caliper without opening pandora's box, I was wondering if I could leave the caliper mounted on the car and just push the piston out using the brake pedal, clean up and replace the seals and put it back together, any ideas out the guys

Hello folks, caliper removed, parking brake cable muscled out of place, no problems, lets see how it goes now, well no improvement. Looked at brake proportioning valve under brake fluid res and it is damp, so I replaced it and problem solved. Great pedal even before bleeding the rears. When bleeding the RR it takes quite a bit of fluid before you get to the air indicating it is coming from upstream and not the caliper