Hi All, a bit of a research project here. I could do with confirming the findings made by a customer (a real Engineer, oily hands and all that) regarding Discovery I front ABS.
As I'm sure many of you are aware, some Discovery I's and Range Rover Classic's suffer from a problem with the fron ABS light always or intermittently coming on. The aformentioned customer found that, after fittng all new parts, after about 18 months the copper sensor bush had "lifted", putting the sensor out of kilter. Pushing it back in cured the ABS light for a coupe of months, but then it did it again. We could find no obvious reason for the bush lifting, and assumed it was down to rotational forces or similar - but we weren't convinced.
Anyhow, he has now had the whole swivel stipped down and it was found that the bearing in the end of the stub axle was not at it's best. Pushing things around it was found that this bearing having play in it allowed the CV joint (and hence the ABS ring) to oscillate - not a lot, but enough for it the nudge the sensor up at the top, and quite likely down far enough for the sensor to miss-read. This, it seems, could result when going over a bump, setting the CV joint "oscillating" enough to trigger sufficient faults for the ABS light to be put on.
The question is - is this right? So, if anyone here is working on a vehicle with iffy ABS sensors and you have the swivel stripped down - can you have a look at the bearing and see if it has play in it?
Should we be right on this, it could save a lot of people a lot of grief (and dosh).
Cheers Richard