Right Rear ABS sensor fubard. Bolt rusted. MOT TIME! Ahhhhhh!

S4_dan

Fire up the Quattro!
VCDS Map User
Guys,

As above my RR ABS sensor is fubard. I've checked the resistance and there is nothing at the sensor plug or ABS monoplug (pins 30 and 31)

I tried to remove the allen bolt but its really rusted and the 5mm allen key just started turning. I don't have enough remove to get my bolt/stud remover on to the bolt head due to the sensor being so close.

On top of that, my MOT is on Friday and I need to get another sensor fitted to put out my ABS and ESP light.

Does anyone have any recommendations on ABS, eurocarparts perhaps? Or does anyone have a working right rear sensor (8E0927807B) laying around they want to part with?

Cheers,

Dan
 

Bainie

Registered User
I had the same problem on my old mini , had to drill out both the bolt and the sensor . I used a europarts special with no issues . They must be set to fail the week before mot time, mine was the same !
 

Manics

Registered User
REVIVAL>

Few tips for anyone that might search this issue. My rear right sensor threw the two orange ABS dash lights. VCDS reported:

00287 - ABS Wheel Speed Sensor; Rear Right (G44) 30-10 - Open or Short to Plus - Intermittent

This job is fairly easy but for the fact that the sensor has been in situ, right by the wheel, for (in my case) 16 years or 175k miles. So nothing wants to come out.

  • Wheel off
  • Brake caliper off (size 13 & 15 spanners). Remove along with brake pads and place it on a support as the brake line will still be attached
  • Remove brake disc (will just come off if you give it a whack with a rubber mallet. You don't need to remove the carrier. Good job too, because your carrier bolts WILL be seized
  • Remove the black dust guard. 3 little screws
  • This gives decent access to the ABS ring (on the hub, with all the teeth which the sensor is aimed at). Clean it
  • You have to break the existing sensor to get it out. No biggie. It's duff anyway. Both its bolt (M6, size 5 allen) and the sensor (part 0265006681 Bosch) will be seized in and corroded in place.
  • Bolt: I hack-sawed the M6 bolt head off, then filed down so that the new sensor can sit flush
  • Sensor: Tap a flat edge down between the sensor and the frame to start to angle off. The back of the sensor with the wire going into it will break away. Hacksaw the front of the sensor (ABS ring side) flat to the frame, then tap out the last few mm of width with a punch or screwdriver whatever. That will leave you with a vacant hole
  • The new sensor is in there very, very tight. You have to tap it back in. You don't need to drill out the old bolt and use a new bolt as the news sensor will be secure enough
  • Follow the wire under the car. Few fasteners to do.
  • You only need to remove the plastic under tray next to the jack point to get to the bottom hole that the wire routes up into
  • The top hole is immediately above the bottom hold; straight line down
  • To get to the sensor connection, remove bottom seat bolster (interior seat) and remove the small nut just underneath the seat, so that you can get underneath the side panel (where the seat belt rests on). This allows you to disconnect the old sensor, drop a piece of string straight down, through both holes, to then pull back up and make the new sensor's connection.
 

HelenB

Registered User
Spot-on, Manics! Could've done with this guide recently. It is a pig of a job, just done it but without removing caliper/disc/backing plate on mine. As above, I destroyed the knackered bolt head to shear it off (I cut a slot in and chiselled it off, was attempting to get it to screw out at that point haha) and leave shaft in as new sensor so tight it doesn't need a bolt. My caliper/disc still fitted method was destroy the sensor everywhere you can get to with a sharp chisel tool and the plastic surrounding the magnets will come away to allow eventual removal by pulling it out rather than tapping out from the other side. It's not tight in the backing plate itself so didn't get lost down near the reluctor ring or anything. It's only tight as hell in the hub. Just takes patience and time. A few bruises from rerouting new wire under the car, easier on a lift or ramp I'm guessing.
I went with £30 Bosch one from Ebay rather than cheaper lesser known brands, I am not doing this job twice! Same as Manics, Bosch number 0265006681 (which definitely replaces 8E0927807B). My dash light went out and stayed out thank the lord.
 
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jp1

Registered User
Just about to try this job myself. Took the rear wheel off today, (which I had to use a sledge hammer to knock off the spindle, first time ever in taking a wheel off in over 30 years!!) to have a good look and spray WD40 everywhere. The job looked tricky. The question I have is it necessary to loosen bolt 2 in the image? It looks impossible to get any Torx bit on that bolt as part of the suspension is directly over it leaving no access. Secondly the point where the sensor cable routes through the body shell seemed a tad tricky to access. I didn't fancy sliding under the car without using additional axle stands. But my question is how difficult is it to feed the cable through at this point and secure the grommet in place when the car is just raised on an axle stand?

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HelenB

Registered User
Just about to try this job myself. Took the rear wheel off today, (which I had to use a sledge hammer to knock off the spindle, first time ever in taking a wheel off in over 30 years!!) to have a good look and spray WD40 everywhere. The job looked tricky. The question I have is it necessary to loosen bolt 2 in the image? It looks impossible to get any Torx bit on that bolt as part of the suspension is directly over it leaving no access. Secondly the point where the sensor cable routes through the body shell seemed a tad tricky to access. I didn't fancy sliding under the car without using additional axle stands. But my question is how difficult is it to feed the cable through at this point and secure the grommet in place when the car is just raised on an axle stand?

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I can't remember struggling with the plastic wire shroud fittings, I think I used a torx bit and socket/ratchet handle on it. I also can't remember if lowering/raising the hub with a jack gives more room for that screw? A helper is advisable for feeding in the new sensor wiring (one person from underneath, one working from up at the seat bolster), like Manics said with a piece of string and splash guard removed. The only bit I had to lay down under the car (with axle stands placed in case my jack gave way) was to get the wiring pushed back into the holders underneath. I was very glad to get the job finished as it was fiddly and plenty of arm bruises/scratches after. A garage with a lift and good tools will make much shorter work of it so unless you're skint I would actually recommend sending it to the mechanics!
 

HelenB

Registered User
Actually I think you can just prise the shroud off that screw No2 once the bolt No1 is removed. Just be careful not to snap the plastic.
 

Venomuk

Registered User
In the process as though it was a sensor but on further inspection, the rings are more like teeth than castellations. The previous owner said it was more of a farm vehicle and think it has been laid up in a field as the bolts and everything behind the wheels look like its been at the bottom of the sea. So I opted for a full rebuild and got some new hub knuckles from Lithuania cheap and in great condition. Had them blasted and painted, fitting new hub bearings with rings and new sensors along with poly bushes. Once I get around to fitting them I will get some pictures up of how bad they are as I'm going to have to cut the heads as there aren't much left of the nut and bolt heads left...
 

jp1

Registered User
I can't remember struggling with the plastic wire shroud fittings, I think I used a torx bit and socket/ratchet handle on it. I also can't remember if lowering/raising the hub with a jack gives more room for that screw? A helper is advisable for feeding in the new sensor wiring (one person from underneath, one working from up at the seat bolster), like Manics said with a piece of string and splash guard removed. The only bit I had to lay down under the car (with axle stands placed in case my jack gave way) was to get the wiring pushed back into the holders underneath. I was very glad to get the job finished as it was fiddly and plenty of arm bruises/scratches after. A garage with a lift and good tools will make much shorter work of it so unless you're skint I would actually recommend sending it to the mechanics!

Many Thanks.

F1 autocentre has quoted me £40 to replace the sensor * £20 for the ABS light diagnostic/reset or about £140 if the sensor is welded in place and the hub needs to come off.

It is not the cost as I can easily afford the garage to do the job, it's the satisfaction of doing it myself. the car now as 200,000 miles on the clock and is the dog transport to the woods. You have to have some little battles in life to win...
 

HelenB

Registered User
I know what you mean, it is satisfying to do it yourself and worth it afterwards, even with the swearing. Mine is at 251k miles now so little victories mean a lot as it doesn't make much sense throwing too much money at it, garage labour costs being the worst. The Bosch sensor was £30 (numbers above if needed, not a job you want to do twice with rubbish parts), I didn't have to turn the dash light off afterwards, it went straight out, but my cheap scanner (£20) would do it if needed - it also gave me the code to know which sensor was bad so has more than paid for itself just on one problem.
 

jp1

Registered User
I have bought the sensor for £16 from amazon.
Today I bought a hex 1/2 drive bit set to tackle the bolt as the Allen key was just rounding off. It did the job, (in shearing off the bolt immediately!!!) but at least I could get the sensor off by hacking it to death with a chisel. I am now just left with the centre part of the sensor held firmly in the base part. I gave up trying to hammer it out as there is really no access, so I ordered a mini drill to drill the remaining part out.

I did plug in the new sensor, to test it, but of course it is not installed yet and I was able to rest the ABS light, but the ESP light has remained on and the code thrown is the steering angle sensor voltage supply terminal 30. I cannot reset this code and the full lock to full lock of the steering wheel has not cleared this (I have recently changed my battery). I am going to assume that since I have not changed my wheel speed sensor, full lock to full lock of the steering wheel plus driving a short distance does not recalibrate the sensor as the wheel speed sensor is still faulty. I shall find out soon, otherwise that is another job.

I hope my Labrador appreciates the work I do on his set of wheels....
 

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Venomuk

Registered User
I ended up cutting the front and back off with a grinder and then hitting the centre out. I did however remove the whole knuckle and refresh the whole thing. it was much easier to just snip the cable and then remove the knuckle to work away from the car.
 

Venomuk

Registered User
Set about doing my rear ABS sensors today till I realised I didn't have all the parts so set about having a poke about and inspecting things. Looks like the car was sat in a field at one point because some parts look like they were sunk with the titanic.. Anyway, I got some photos and wanted to know the opinions if this is something to worry about and needs addressing ASAP. Around the rear subframe mounts/bushes I found some corrosion, gave it some good pokes with a screwdriver and feels solid.

Advice on preventing it from going any further or is it too far gone to be saved?

 
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