In common with many other drivers, I've got a problem with my ABS. It started as an intermittent fault indicated on the dashboard along with the ASR, which soon became a permanent feature on start-up. Had a look at the system with a diagnostic tool which indicated a fault somewhere on the offside rear wheel. The car was due in at the main dealer for a test on the air-conditioning system, so I asked them to take a look at the ABS as well.

 

On the ABS the word came back that the OSR wheel bearing was worn out and needed replacing along with the sensor which had been damaged by the excess play in the bearing. That will be £ 306.- (together with £ 521.- to fix the air-con), a short discussion followed, I paid £ 50.- diagnosis fee, and took the car away. Now, last June I had renewed the discs, pads and stone guards on all four wheels, which meant in the case of the rear axle removing the hubs. Naturally checked the bearings which were perfect then, with absolutely no play, and are still the same now. The hubs spin with no audible noise that would be associated with a worn bearing. And at 75k miles you would'nt expect bearing wear to be present - not on today's vehicles anyway.

 

Decided to strip down the OSR to do the usual thing of replace the sensor. Couldn't do a continuity test on the sensor because the tester probes weren't thin enough to get into the socket (must get something better from Maplin). Thought that if the hub was out of the way it would make removal of the sensor that much easier. In the event the sensor was seized solid, but didn't look chewed on the end as I was led to believe it would be. On removal of the hub and bearing, noticed that the reluctor ring (which in this case looks like a rubber ring with an imprinted segmented pattern on the face) appears to be bio-degrading with many cracks in the pattern and small bits coming away. So I'm now thinking that the problem is a new reluctor ring / sensor combination. Anyway whilst I'm here I'll give the hub bearing shield-ring face a clean along with the stub-axle carrier, and a bit of WD40 around the sensor ready for when it could have to come out.

 

Put the hub back, as I needed to use the car the next day, meantime thought I'd look on the Forum for replacement reluctor rings and if there was a known problem with the "rubberised variety", and if I should be looking to up-grade all the rings with something else.

 

Anyway, took the car out the next day - and the problem appears to have gone away. No ABS warning light after initial start-up and no ASR light either. Ran the car at speed, up to 85 mph, 20 minute run  all Ok.

 

Can it be the case that all that was needed was a clean? Because all I did was remove a little dirt from the bearing shield ring / reluctor ring recess (as much as anything to get the FAG part no.)

 

Had I been less familier with the vehicle and more trusting of the main dealer, this would have cost me £ 300.-(admittedly there would be new parts and some kind of warranty), but I think there is also another moral here, the main dealer customer car park was the clearest that I had ever seen it - practically empty - perhaps I should have taken note!

The usual problem is a rusty reluctor ring. A bit falls out eventually leading to false readings. Sometimes the ring can expand when it rusts to rub on the sensor but tbh that seems to be pretty rare.

 

I had to change both rear hubs on my VRS for this problem but £300 FFS what a rip off, even more so £50 to read a code, you can by a reader for £10. I was £170 at an indy and he used VAG parts which were significantly dearer than pattern so it could have been even cheaper.

 

Dealers are shooting themselves in the foot with these prices. Skoda wanted £200 to supply two front disks, I was able to buy and have disk and pads fitted for less than that.

 

SWMBO got quoted £1k for disks and pads on her BMW 116i. Parts are about £200 on ECP for Pagid. I could have Brembo kit fitted for less than that.

Edited 13 May, 201511 yr by Aspman