Brake issues

[charlie_boy]

I have not been happy with the brakes on my P38 since I bought it 2 years ago. I had the rotors machined and new pads fitted but it didn't seem to make any difference. Then my master cylinder failed so I've recently had it replaced. Only a few days after it was replaced I've now got ABS and Traction Control Failure every time I start the car.

I'm pretty sure the brakes have been bled properly. I checked the accumulator a while ago and it was OK. When starting up, the ABS pump runs for about 15 seconds before it cuts out. Something that puzzles me is that every time the brakes are pressed the ABS pump runs. I'm pretty sure the accumulator should store enough charge for a few brake presses.

I'm not sure what else I can check or what the problem is.

For the amount of money I've spent on the brakes I could have bought myself a nice classic. It's looking more and more tempting to fit an aftermarket Master cylinder and vacuum booster. My ABS and traction control isn't working anyway. I miss my classic sometimes.

[Rupert Prior]

the abs faults on startup but with no logged faults is normally due to low voltage in the system (usually the battery). the pump running every time the pedal is pressed is usually the accumulator, (try waiting for the pump to reach full pressure and stop, then turn off the ignition. try to judge a normalish brake pedal press and see how many of these it takes before the pedal resistance changes dramatically. 16 to 25 is ok but less than 10 would mean the accumulator could be suspect. i suspect yours is less than 3)

[charlie_boy]

Thanks Rupert

The pump charges the accumulator very quickly. I turned the ignition off and like you said, on the third pump the pedal sinks in to the floor. The pedal feels more firm with the ignition off which does not seem right to me . I'll have to try another accumulator.