Seized/dragging brakes

[PaulyH]

I've sold my s3 and purchased a 2001 a4 tdi as a diesel commuter and have been having problems with all the brakes (front and rear) dragging to the extent that they really slow the car down. It wasnt like that on the test drive but now its happened 3 times and luckily each time I've been very close to home so could get home ok.

I had all 4 brakes smoking the first time it happened and this was after a few successive stops. It wasnt until I pulled up that I noticed the heat and smoke coming from all 4 corners of the car. It also heated the alloys up so they were very very hot to the touch.

Now had it been just one brake, I would have put it down to either a hose collapsing or a sticking caliper, but the fact all four are dragging makes me think it could be the master cylinder.

The servo also seems to be working as when i press the brake and then turn the engine on I can feel the pedal drop further.

Does anyone have any advice, experience or thoughts on this?

Thanks in advance!

 

[technics100]

I had problems in one of my A4's with the brake pedal sticking down, while driving along put your foot under the brake pedal and see if you can pull it back up, see if that does the trick.. I swapped the servo and it still happened..

 

[PaulyH]

I tried that but it doesnt seem to get stuck or come up at all. The pedal does feel pumped out after a few minutes driving though.

 

[PaulyH]

I've now taken the car to a garage to fit a new master cylinder and the numptys at Audi gave me a clutch master cylinder instead of the brake one. The garage did however, have a look at all 4 calipers and it seems that the previous owner greased them all up prior to me buying the car so they were well aware of the problem, just not great at finding a solution or telling me there may be problems with them!

The new brake master cylinder should arrive tonight and be fitted tomorrow so I'll let you know how I get on. If its not the M/C I'll be having the ABS pump changed.

 

[PaulyH]

It looks like its got a corroded servo and MC due to the servo absorbing standing water from the scuttle panel.

Oh dear.