wow...brake issue.....completely puzzled...?

[DoctorD15]

Alright this is the second time that this has happened. 1987 Quattro 5000cs turbo. Has been driving fine for months from when i got it, but about a month back this same brake issue happened again. Same types of things have happened each time.

Im driving highway, 5th gear for a while, when the wheel gradually starts to shake more and more. As i slow the shakin does descrease so this probably does not have to do with the brakes but who knows. I get my destination, shut the car off do what i gotta do come back, turn the car on, start driving then my brake pedal goes straight to the floor. The first time i pulled over and checked fluid, lines and everything, no leaking no nothing. I wait it out and the brakes come back and i make it back home. S

Second time same shakin occurs (not sure if its even realted) but the brake goes to the floor once again. I keep going (being in a development) and expierment. The brake goes very far down until its mabey about an inch from the floor until it starts to slow the car down. If i pump the brakes it comes up and works closer and closer to were it should, but once i start going again, it goes back to the one inch away working type deal. As i keep driving the brake gradully comes back to normal. Once again there was no leaking (although i did notice a but around the cap where u pour the fluid in and a bit around the seam of the fluid resovoir tank, (but a very minimal amount, may have just been there from when i filled up weekes ago)but the lines looked fine, fluid was full. Im completely baffled. Does anyone have a clue of whast going on?

 

[Rev-head]

Have you checked the bomb ?...........Shake could be caused by warped discs ..would check over all the wheels rear and front for leaks i.e flexi pipes and all .........check all the pipes that assist brake servo as well

Link will help have a good read

http://www.sjmautotechnik.com/trouble_shooting/brake.html

 

[28v6]

I'd go with Rev on this one, Not only check that the "Bomb" works (although from memory if its not working the opposite effect happens, i.e the pedal goes rock hard and not soft!) but I think that you've warped a dics AND have a siezed caliper. It sounds as though the caliper has extended to far hence the travel on the pedal and the disc has warped due to permanent contact.. You may have to replace the calipers, normally its the rear that have caused this problem, a common fault on these cars as is the handbrake mechanism - tends to sieze on and stretch the cable.. check your rears first, I'm betting that they've extended and siezed in the on position and that the pads are now down to the near metal position...