ABS rings

[asahartz]

For a while now I've been getting messages in the display. The car started with "Anti-skid temporarily off", then "Anti-skid service required" and "Brake service required". Shortly after that we got "Brake failure - stop safely", though the brakes were working fine.

We took the car and had the codes read at our local independent, where they told us that it was mechanical not electrical.

I looked under the car at the hubs to find that both ABS rings had split.

The rings are available online for about £15 each, but for speed we paid twice that from the Volvo independent. Using a description found on another forum, my son and I replaced the rings - one was split and the other completely broken in two - taking around 20 minutes each side.

So a fairly cheap fix for what seems to be quite a common problem! Yet it took some searching to find a description of the issue, so here it is (originial description from Swedespeed forum):

- Block the car wheels and put the car in neutral so that you can spin the axle by hand later.
- Jack up front wheel and remove it.
- Remove ABS sensor and hang out of the way.
- Remove the 2 big strut bolts. This will allow swinging the hub assembly out of the way so you can pull the axle out of the hub.
- Loosen the axle bolt and tap gently to get the axle moving back out of the hub.
- Pull the axle from the back of the hub and prop it up using a 2x4 between it and the lower control arm to put the axle end above the brake disc.
- Remover the old reluctor. This should be easy if it is cracked. My came off by hand.
- Clean the surface where the reluctor was using a wire brush, files, or whatever. Mine was extremely corroded, but files and then a brush did the trick. Spin the axle to make sure it is cleaned all around.
- Heat the new reluctor to a blue color using a plumbers torch or similar. (I used the gas burner in my adjacent campervan!) Takes a couple of minutes.
- Put the hot reluctor on the axle using pliers and gently but quickly tap it in place. Use a drift (metal or hard wood) to seat it.
- Let it cool for a couple of minutes.
- Put everything back in place by reversing the above procedure.
- Clear the ABS codes with VIDA (I haven't done this yet but took the car for a drive - as soon as it went over 30mph and returned a normal ABS signal all the lights were extinguished and no messages have returned in the display).

[Orangemoon]

You just saved my life! Ta pal!

[andyKent]

Originally Posted by asahartz

For a while now I've been getting messages in the display. The car started with "Anti-skid temporarily off", then "Anti-skid service required" and "Brake service required". Shortly after that we got "Brake failure - stop safely", though the brakes were working fine.

We took the car and had the codes read at our local independent, where they told us that it was mechanical not electrical.

I looked under the car at the hubs to find that both ABS rings had split.

The rings are available online for about £15 each, but for speed we paid twice that from the Volvo independent. Using a description found on another forum, my son and I replaced the rings - one was split and the other completely broken in two - taking around 20 minutes each side.

So a fairly cheap fix for what seems to be quite a common problem! Yet it took some searching to find a description of the issue, so here it is (originial description from Swedespeed forum):

- Block the car wheels and put the car in neutral so that you can spin the axle by hand later.
- Jack up front wheel and remove it.
- Remove ABS sensor and hang out of the way.
- Remove the 2 big strut bolts. This will allow swinging the hub assembly out of the way so you can pull the axle out of the hub.
- Loosen the axle bolt and tap gently to get the axle moving back out of the hub.
- Pull the axle from the back of the hub and prop it up using a 2x4 between it and the lower control arm to put the axle end above the brake disc.
- Remover the old reluctor. This should be easy if it is cracked. My came off by hand.
- Clean the surface where the reluctor was using a wire brush, files, or whatever. Mine was extremely corroded, but files and then a brush did the trick. Spin the axle to make sure it is cleaned all around.
- Heat the new reluctor to a blue color using a plumbers torch or similar. (I used the gas burner in my adjacent campervan!) Takes a couple of minutes.
- Put the hot reluctor on the axle using pliers and gently but quickly tap it in place. Use a drift (metal or hard wood) to seat it.
- Let it cool for a couple of minutes.
- Put everything back in place by reversing the above procedure.
- Clear the ABS codes with VIDA (I haven't done this yet but took the car for a drive - as soon as it went over 30mph and returned a normal ABS signal all the lights were extinguished and no messages have returned in the display).

I just wanted to follow up since I followed these directions almost exactly (and, of course, thank you!).

There were a few things that I thought might be useful to the next guy;

1) The ABS sensor doesn't need to be removed after all, just the two rubber grommet/holders which would otherwise put strain on the sensor/cable when the hub falls down. I had a strong feeling I'd break the abs sensor trying to get it out anyway and happily left it alone (the rubber jobbies just need to be pulled and jiggled firmly out).

2) After removing the rusty old broken ABS ring, I basically chiselled the big corroded bits (and bits of stuck plastic/paint) off and then used the wire brush to make sure that when I tapped the new ring on there would be nothing to stop it reaching the elbow. The surface doesn't need to be pristine or mirror finish.

3) Putting the new ring on without heat is not difficult, it just needs to be 'gently' tapped into place using the drift, moving slowly around the ring and at opposites (a bit like how a drum skin is tensioned in opposite pairs). Takes patience to get it to take in the first place (just slips initially until it grips) but is plain sailing from then onwards. Probably a bit slower but less stressful than a blow torch. I used a 'wood drift' (that means a piece of brio track, which is what I had to hand).

4) Getting the axel out of the hub means pushing it out gently using the axel bolt (after gentle tap).

5) Putting the axel back into the hub required adjusting (twisting) the angle of the hub randomly until it went in easily - needs to be lined up.

6) After the strut bolts come out and the hub falls forwards, the suspension (with the coil) turns violently because it's held under tension. This means that (for replacement) it must be twisted and held straight before the hub can be replaced and strut bolts replaced. This was quite a faff as it's difficult to get the leverage on the coil whilst moving the hub and keeping it all straight enough to get it in. I ended up holding the hub forwards with my chest whilst wrestling the suspension and strut bolts with my hands.
(I.e., it isn't as nice as a 'reverse the above procedure' because letting the hub drop out is a procedure of 'flopping' but getting it back in is a little more fun!)

7) WD40 is probably essential overnight for getting those strut bolts ready to go for an oldish car (2004 in my case). Mine were so corroded that the correct sockets couldn't hope to get on and I ended up wire-brushing the nuts and the bolts for about 20 mins before applying the WD40 (twice) and waiting a night before I applied breaker bar(s). Even then, I ended up having to hammer the sockets onto the nuts (after WD40 in the sockets to stop them getting stuck). Otherwise, with corroded nuts/bolts, it's very easy to end up trying to use sockets which are too large and rounding the nuts with a breaker bar.

8) I put the car back in gear (1st) in order to tighten the axel bolt as it will just freely spin otherwise.

A very rewarding job for a novice like me.

Andy

[cheshired5]

Having done this several times, I would add further that both strut bolts do not need to be removed. It just adds an extra pain to reinstall.
Remove the top strut bolt only and loosen the bottom bolt and this will allow the hub to pivot forwards.
If you need more wriggle room, simply unbolt the track rod end from the hub and you'll have all the space you need.
Hot rings make the job noticeably easier so those without blow torches, just put the rings in oven for 15 or so minutes.

[andyKent]

Originally Posted by cheshired5

Having done this several times, I would add further that both strut bolts do not need to be removed. It just adds an extra pain to reinstall.
Remove the top strut bolt only and loosen the bottom bolt and this will allow the hub to pivot forwards.
If you need more wriggle room, simply unbolt the track rod end from the hub and you'll have all the space you need.
Hot rings make the job noticeably easier so those without blow torches, just put the rings in oven for 15 or so minutes.

This sounds very sensible - am doing the other ABS ring later so will try without removing bottom strut bolt (should save a lot of wrestling!). Ta!

Andy

[andyKent]

Originally Posted by andyKent

This sounds very sensible - am doing the other ABS ring later so will try without removing bottom strut bolt (should save a lot of wrestling!). Ta!

Andy

Ok, so I did the other (front) wheel yesterday.

Doing the previous wheel the axel came out by merely pushing on the axel bolt gently (after a 'gentle tap'). The second wheel did not release its axel so gracefully at all. This time I had to lever the axel out against the old ABS ring (using an old/large allen key, which was what I had to hand with the required L shape). It turned out that this axel was more or less new (fitted by previous owner I guess) and (unlike the previous axel) it was greased - i.e., it was tight and not rounded at all (the other one must have been original and was relatively rounded and dry).

Regarding the strut bolts - I did attempt to get the axel out without removing the bottom strut bolt (and it would have worked fine if not for tight axel) but struggled to get room for the leverage and ended up taking both bolts out to get more wiggle room. Ultimately, however, I don't think this was necessary because at the point I removed the bottom bolt I had not yet worked out how to lever the thing out, so if I'd begun with the idea of (and a more suitable tool for) levering the axel out it would have gone much smoother.

This time, as well as chiselling and wire-brushing the rusty hub, I took the time to smooth the leading edge of the hub (where the ring must first pass/seat before going into place) and again tapped it on cold. Much faster this time because the leading edge of the hub was smoother. Definitely quicker than getting the oven up to temperature (but probably still much slower than using a blow torch).

Also in contrast to the easy axel replacement for the previous wheel, getting the tight axel back in again was a case of putting it in as far as possible and then using the axel bolt to (carefully) pull the (properly located) axel into the hub. With both strut bolts removed, the wrestling was again fairly strenuous (and probably unnecessary as already noted).

No more ABS lights.

Andy

[cheshired5]

Originally Posted by andyKent

Regarding the strut bolts - I did attempt to get the axel out without removing the bottom strut bolt (and it would have worked fine if not for tight axel) but struggled to get room for the leverage and ended up taking both bolts out to get more wiggle room.

When trying the one strut bolt method, did you also undo the track rod end?

[Namo Amituofo]

Dear all

I'm fairly new to this forum (and to mechanics) - had a disastrous day today thanks to my XC90's ABS warning - and found this thread on Google. I wonder - if my car's problems are caused by ABS ring? Please could you take a moment to read details below and give me your thoughts? Any tips would be much much appreciated!

For my very old 2004 XC90 T6 - I've recently replaced serpentine belt and tensioner/pulley - and for this job I removed ECM TCM modules as otherwise the tight clearance made the job literally impossible. I used a ECM/TCM removal tool and disconnected battery negative on a cold engine before the job. After the job, I reconnected battery and turned ignition to position II - did a test drive and all seemed OK.

Today I had the 3rd trip after the job mentioned above - and I was stuck in really bad traffic for 45 min - I pretty much didn't use the gas pedal as could just rely in pressing/releasing the brake to move at that slow speed. Then - suddenly - ignition was playing a bit funny - it was 'auto switching' off/on itself multiple times (sorry don't know the technical language for this) - at first I thought it was due to engine being idle for too long - but then the frequency increased to once every 30 seconds also - at which time 'airbag service urgent' warning message also showed up.

I continued to drive (in bad traffic) - and suddenly the 'brake failure stop safely' message came up - at which point I lost all electronics - gear light was gone, DIM was gone, and signal lights not working - but the engine was still running and I was able to accelerate / brake just like normal. However once cleared of the traffic jam I had to pull over (without being able to signal...!) to switch off and on ignition - which gave life back to all electronics - only to get the same 'brake failure stop safely' message again within a couple of minutes...

Luckly when the above happened I was close to home - still had to stop / switch off/on ignition 4 times to get home - and did all this with our little baby aboard!! I remained calm and get us back home safely eventually.

Some FACTS:
- Starter motor, starter switch and ignition barrel was changed in Feb 2017 (by previous owner)
- Brakes were serviced late last year (by a good local shop) - all working fine
- I've recently disconnected ECM/TCM and reconnected them - car did two trips afterwards - both fine
- The aforementioned problems started with ignition playing funny - then 'airbag' warning message - then 'brake failure' warning message - then loss of all electronics.

my SUSPICION:
- The car had been stuck in bad traffic before (albeit just for a few minutes - not as bad as today's) and was fine
- the only thing had changed was ECM/TCM disconnection/reconnection - could I have messed up something with my amateur job?
- ABS ring failure as described in this thread?

Any help / advice would be greatly appreciated.

Thank you in advance.
Namo Amituofo

[SwissXC90]

You may be suffering a DIM bad solder joint problem, and you can get your DIM fixed in London for a very good price, see here:

https://volvodiagnostic.com/shop/ind...duct&id_lang=1

[RoyMacDonald]

There are a number of electrical corrosion issues that it could be. I would advise taking it to Charlwood Volvo. http://charlwoodautomotive.com/

Peter Suchy is brilliant at diagnosing and fixing electronic faults and will probably save you money in the long run.

Roy