**SOLVED!**-Alfa 156 2.4 20v Brake Servo replacement?, brake pedal sticking down !
Somebody help!! I have seemingly one of the worlds rarist brake problems in that my brake pedal is sticking down and keeping the brakes applied. This is happening more or less all the time during normal braking and the pedal sticks down for a varying amount of time (seconds) and normally requires a foot underneth to remove. The fault first appeared after car was left over weekend and then driven to work on Monday. I have ascertained that it is only sticking when the servo is active, when the vaccuum supply to servo is disconnected it is not doing it but then the pedal is hard and car has limited braking.
1. So far I have changed the front and rear pads (they were all low) - no difference.
2. Cleaned and greased all the sliding pins, no sticking calipers as far I can tell.
3. I have changed the brake fluid and the rear rubber brake hoses (can collapse internally) - bled the system manually via the pedal, all 4 corners and no difference.
4. Changed the metal rear brake line to driver side rear wheel which developed a leak towards fuel tank area during the bleeding process (maybe conincidental) although I cannot be sure that this was not leaking before we started bleeding but the system did not appear to be loosing fluid prior to this.
I have spoken to a few places regarding the problem and of course nobody has really heard of it before. Suggested unlikely to be the servo probably because it is acting on the pedal and still providing assistance, also probably a rare failure, but I am not convinced. My other thought is master cylinder related although generally I believe this would result in loss of braking effort. 3rd idea is ABS pump related but the ABS warning light is not activated. Also remote possibility still air in the system ?
So my main question aside from what it might be (ideas welcome) is taking worst case scenario what is involved in changing a brake servo on a 156? Has anbody done this before, I can see its buried under the dash behind the pedal area, is it a dash removal job?, I'm fairly competant diy mech but dash removal would not be pleasant !!
Last edited by italiancarfan; 03-07-14 at 15:28.
Reason: Problem solved