front ABS sensors......ARRRGGGHHH!!

[Zip]

....christ, why didn't anyone tell me how bloody difficult it is to get the front sensors out of my 2002 s8...?

Drivers sides, had to take caliper, disc and dust shield off to get enough leverage with my grips (and thick screwdriver to prize out at the same time). Sensor now chewed to b**gery, and mounting plate (with grub screw hole) now cracked.

Excellent.

Now on to passenger side...

Manage to strip one of the 10mm hex heads on the brembo calipers. Arrgh!! How the hell do I get that shifted now? Down to a garage with some
airtools, me thinks.

Anyway, all reassembled after a couple of gallons of WD40, brake cleaner, and copper grease, and ABS errors have gone and all ok.

Still need to get that caliper off...

So...who's got the best FL ABS sensor removal technique....?

Zip

[Mr K]

erm, am i missing something? whilst doing my front arms i took the ABS sensors out and gave them a wipe to get all the bits off them.

Not sure why need to go near the caliper, or which 10mm bolt you have stripped. It it not the small allen bolt on the upright, then pull them out? opposite side of the upright to the caliper iirc (although i cant picture it in my head).

[Zip]

...would have loved for it to be a simple pull out job. No idea why mine are so seized compared to others. The bore into which the sensor slips is quite rough and corroded on the inside.

As I said, I had no choice but to take the dust guard off (which involves removing the disc) to allow me to get a pair of grips onto the metal part (where the allen grub screw goes through) without crushing the plastic of the sensor itself.

Sounds like you have just been lucky. Weird, 'cos my car has only done 76k miles.

Zip

[Mr K]

hmm, sounds like a right pain! I feel for you having spent an entire morning drilling out a pinch bolt the other day... why couldnt audi have used better metal / assembly lubricant.

[Duffy]

I stripped one of the same caliper retaining bolts on mine last week whilst doing discs and pads.
Drill the head off (I used a 10mm drill then stepped up through 1mm increments to 13mm) and then pull the caliper off, the screw came out by hand thereafter.

Time consuming but straightforward enough in the end.

[Zip]

Originally Posted by Duffy

I stripped one of the same caliper retaining bolts on mine last week whilst doing discs and pads.
Drill the head off (I used a 10mm drill then stepped up through 1mm increments to 13mm) and then pull the caliper off, the screw came out by hand thereafter.

Time consuming but straightforward enough in the end.

Sounds sensible. I was thinking of cutting a wacking great groove with a Dremel, but then I would need the mother of all screwdrivers!!!

[Duffy]

Drilling the head off is definitely easier...........

[ulfilias]

Ok....I'm with you, Zip all the way on the screaming....Mine will not come out and has broken the sensor inside the hole. Looks like it was a magnetic bar inside a white plastic sheath, inside a black plastic sheath. The Aluminium has exfoliated (Like rust, Aluminium does oxidise, particularly in the presence of water) and trapped the plastic shaft/sheath inside.

I am slowly chiseling away the plastic as i can't think of anything else to do. Maybe remove the drive shaft (*panic*) and push it out.....At this rate i can almost see me needing a new arm !!!

Irritatingly my elsawin is showing the old style for my car. Quite odd.

sensor seems to be 0 265 006579....Where is the part number ???

Ta,
Lee

[Zip]

Originally Posted by ulfilias

Ok....I'm with you, Zip all the way on the screaming....Mine will not come out and has broken the sensor inside the hole. Looks like it was a magnetic bar inside a white plastic sheath, inside a black plastic sheath. The Aluminium has exfoliated (Like rust, Aluminium does oxidise, particularly in the presence of water) and trapped the plastic shaft/sheath inside.

I am slowly chiseling away the plastic as i can't think of anything else to do. Maybe remove the drive shaft (*panic*) and push it out.....At this rate i can almost see me needing a new arm !!!

I recognise the "exfoliating".... bit like layers off an onion peeling off in the hole. I was loathed to clean it out too rigorously in case I left a load more swarf in there.

Apparently replacing is a right royal PITA, as the cable runs back to the control unit are a nightmare to trace. Someone on audipages has soldered on new sensors to existing cables....do a search.

Hope I never have to touch the little f***ers ever again... and all that for the TINIEST little bit of black plastic that was caught on the end of the sensor corrupting the readings. I suspect a compressed air hose into one of the wheel bolt holes would have been just as effective...

Still got to drill out that caliper bolt though....arrrggh.

Zip

[ulfilias]

Hi there,

the Audi pages is here : http://www.audipages.com/Tech_Articl...eshooting.html

However that is for the earlier model, without the allen screw. Reading some posts it is quick and easy and others (like mine) are a bitch. It seems the earlier model without the screw is easier.

Also he spliced the cable in as it was cheaper than buying a new sensor for the sake of a wire fault.

Looking at mine, the connector isn't quite on view in the wheel arch as the older model, but is tucked away under the plastic internal arch. A few plastic nuts and it can be bent back enough to disconnect.

Also the cable on the ones with a screw also includes the brake wear sensor cable

I have now spent half the day digging & drilling the sensor out. It has not been easy, but is finaly out. I was worried when drilling some of the plastic that i would damage the rotor, doubly so when i saw copper tones, but no, that is how the sensor is made. There is a big magnetic rod (1" long) and a second domed bit (1/2") with copper windings arround. I know this as i dug it all out and finaly the end cap came in one. Checked the rotor and i hadn't got near with my 1/16" drill bit - tiny and slow, but better than a new rotor.

I've now plugged it waiting for a new bit from ebay. 4D0 927 803 D - The D is for 18" wheels. There is also an E varient for 20" wheels, so in theory if you swap wheels you should also swap sensors !!! Although i guess if they are all the same size wheel the ABS would be fine as it is comparative speeds ?

Audi £152.68, Ebay parts seller £67.49 for a new genuine part, so not too bad i hope - partsdepot_uk

Cya,
Lee