300tdi abs

[damianfitch]

hi all, i have a 1997 2.5tdi with my abs light on and off intermittently. occasionally when braking , ( usually a low speed ) my brakes are juddering. I had it diagnostic checked, the bloke said it is saying AIR GAP IS TOO LARGE. how do i overcome this ( can i ? ).
Any help or advice would be appreciated.
Thanks Damian

[TEMPL4R]

Check the sensors are properly in the holes. Follow the wires to the hubs.

Chris

[damianfitch]

Cheers, they seem to be sat down as far as they will go, was thinking of removing and cleaning to see if any muck there

[TEMPL4R]

A very common and similar thing happens to Rovers when you are pulling up and just before you stop, the brakes judder. That is a cracked slip ring ( the stator, cog or whatever other people call it) that the sensor picks up on.

Chris

[damianfitch]

thanks mate, are they easy to see or do i need to strip something down to check them.
Thanks

[damianfitch]

Can anyone explain the process of checking to see if ring is broke, and how to change it ??. Can they be bought seperatley and where from. thanks alot .
Damian

[bananahead]

If its the part im thinking of then it is just a toothed ring on the cv joint. So to check it you would really need to remove the cv joint, not a 5 minute job im afraid..

[StrangeRover]

The method for setting the air-gap is to set the sensor against the rotor: As the CV joint rotates it pushes the sensor away (until there is no contact). Use a piece of wood (so that you don't damage the plastic cap) and a small tap with a hammer to re-set it.
If the problem persists, check for excessive wheel bearing movement and adjust as necessary. Also check that there is no excess axial free-play where the CV joint attaches to the drive-flange (under the plastic cap). There are shims behind the circlip.
You will need to split this joint if you need to adjust the wheel bearing so may as well check it at the same time.
If you decide to extract the sensor clean all the crud from around the hole first. They are a push-fit and sometimes they can have copperslip on (makes life easier) and I have even seen silicon sealant. Once the sensor is out it is possible to poke a srewdriver and rag down the hole and rotate the CV to pick-up any crud that may be in there. Unless you have access to elephant-size Q-Tips that is!
Keep us posted.