Thread: ABS Problem

Hi Dave,

More than likely a loose wheel bearing, OR the needle roller brg that locates the CV shaft in the stub is worn/ loose.

I'd go with the wheel brg first.

JC

Thanks Justin. I did think of that. There is a very small amount of play in the bearings, to me not enough to warrant the work to adjust if it was a non ABS, but in this case I will tighten them and see what happens. I will report my findings for the benefit of others.

Dave.

Dave,

I have seen some ABS equipped D1's with heaps of WB play but no sensor issues, others require almost NO play or the light will go on. Another point, SOMETIMES the excessive airgap fault code CAN also mean a sensor is intermittently faulty.

JC

It had crossed my mind as to whether an old or faulty sensor would not work with the same gap as a new one. Justin, is this what you are suggesting.

Dave.

I have just been looking at pictures of CV joints. I see that the ABS ring is part of the CV. My CV's are worn, they rattle on full lock, quite loud when centre diff is locked.

Do/can worn CV's when driving straight, spin out of round and knock the ABS sensor?

Dave.

YES.

JC

Why then is there no drive line vibration?

Dave.

I have adjusted the wheel bearing and it seems to have solved that problem.

My next problem. Firstly, when I drive off the ABS light goes out at about 7 kph, as it should. When I stop should it come back on or does it just do this from the first drive off after starting vehicle. I have been driving with the light stuck on for so long I have forgotten. In my case it stays off until I switch off and restart the engine

Secondly I am still having problems with my braking. Some times when braking the pedal feels like the ABS is activating even when there is no wheel lock up. When this happens the stopping distance is increased. This seems to have corrected itself since fixing wheel sensor problem and clearing fault.

What is now happening is(and this is intermittent) when braking it feels like the ABS pump is working but pumping back at the pedal. The pedal hardens up with spring and grinding type noises. When I push really hard I overcome it and braking returns to normal.

I suspect this is a dodgy ABS pump but before I source another one is there anything else it could be and checks I can make?

When I do a self test it shows up as all good.

Also are V8 and TDI ABS pumps the same?

Dave.