A strange ABS issue

Carolyn · March 24, 2017, 18:12

When I said I did some research: I googled 'ABS operating at low speeds'. The subject came up with one highly technical paper in two parts, that studied it all with oscilloscope traces and ended up finding corroded parts causing the problem. The rest were forum after forum for every kind of car that has ABS.

I looked though them and came up with that list representing what these forums reported.

Reading our own thread: I drove a car with the symptoms, and I've driven my two cars that don't have the symptoms. It's not the driver. Knowing Schazzle and Jon it won't be warped discs or sticky calipers.

It is an amazingly common problem. Almost always on older cars.

Let's see what Jon comes up with.

shnazzle · March 24, 2017, 18:22

I still find it odd that it started in my case with the addition of coilies.
But I seem to be alone in this so I guess it was a coincidence. Looking forward to Jon's findings

woodypk · March 24, 2017, 20:27

Quote from: "Carolyn"It is an amazingly common problem. Almost always on older cars.

It's strange because my new '2 is from 2006. Yet my PFL MY2000 never had the problem. And all my scalpers and sliders were cleaned up and re greased so they shouldn't be a problem.

Anyone know where I can find the sensor to check it out?

Carolyn · March 24, 2017, 20:50

On the end of the wire going to the hub.

jonbill · March 25, 2017, 07:09

I feel the weight of expectation. [emoji3] I didn't get very far yesterday I'm afraid. I did fix the arb drop links on my datsun tho.

stupink · March 25, 2017, 08:15

Just to add, if the wheels ARE actually locking not just abs kicking in (you can test this by pulling the abs fuse).. it could also be what I had which was the ABS unit itself failing its job as a bias valve due to getting gunked up, most likely because I got lazy and fitted new pads quickly and just pushed the calipers back rather than letting the fluid and any gunk in the caliper out the bleed nipple... So when the disks/pads were done if you did similar it could also be the issue.. though it does sound a bit more like its the ABS rings.

shnazzle · March 25, 2017, 08:31

That is how I last did it to be honest... And every time before that. It is laziness.

phaeton · March 25, 2017, 12:50

Standard practice isn't it if you let the fluid out just remember to replace it

jonbill · March 27, 2017, 18:40

I had a go at mine yesterday and couldn't budge anything so I gave up on just inspecting all 4 corners.
I'm waiting on some diagnostic kit to help me see if one wheel is showing different speeds from the others so I can zero in on which wheel to hit with a hammer.

jonbill · March 30, 2017, 17:18

So, wheel speed sensors seem to be all showing about the same speed when the abs kicks in, so not an obvious reason so far.
I'll have to see what I see on longer use when the car comes of sorn.

Carolyn · March 30, 2017, 17:29

Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.

Call the midlife! · March 30, 2017, 18:15

Quote from: "Carolyn"Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.

I'm sure Shnazzle will be along soon [emoji2]

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shnazzle · March 30, 2017, 18:53

Are you saying I'm a little bit of filth?

Call the midlife! · March 30, 2017, 19:35

Quote from: "shnazzle"Are you saying I'm a little bit of filth?

Maybe, just a little...

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jonbill · March 30, 2017, 21:21

Quote from: "Carolyn"Be interesting to see what a real soaking all over with brake cleaner and a thorough blow-out with an air-line would do. I'm suspecting a bit of filth somewhere.

It looks like I have to dismantle quite a lot of rusty stuff to be able to clean anything - so I'd rather do it to only one corner if I can.

jonbill · March 31, 2017, 09:10

Supports the idea there's some crap between reluctor teeth: m https://www.picoauto.com/library/case-s ... -abs-fault m

Carolyn · March 31, 2017, 17:15

I read that one too. A lot of stuff to wade through to get to 'unbolt some stuff to find muck and rubbish'.

I thought (could well be wrong) it was front offside on your car....

jonbill · March 31, 2017, 17:37

Yes, thats what we both thought, but I still have in the back of my mind that it was left rear that I'd tried to remove when I took the engine out, so I suspect that one too.

Carolyn · March 31, 2017, 17:42

Ah... might not be properly seated?

jonbill · March 31, 2017, 18:01

Quote from: "Carolyn"Ah... might not be properly seated?

It never moved a mm, it was rusted in solid. But maybe some rust dropped in the reluctor ring. Thats my thought anyway.

jonbill · April 22, 2017, 14:41

Ok so I know what my ABS problem is.

Rear left reluctor ring broken.
I think I've seen a pic on here before like that, so maybe not uncommon.

The prob is either the extra separation between those two teeth or possibly that the ring is now loose on the hub and can move relative to the sensor.
In the (probably vain) hope that its the latter, I've glued the ring in place and I'm going for a test drive.

Carolyn · April 22, 2017, 17:45

Bugger. So it was the ring. I was at The breaker's today, could have picked up a drive shaft for you...

phaeton · April 22, 2017, 18:21

Well done finding it, you can buy just the rings FLEECEBAY I did them on a Peugeot just tap them into place nice & steady.

jonbill · April 22, 2017, 21:55

Thanks - I've just ordered one. Nice and cheap.
I'll have to read up now on how to get the shaft out of the hub.

Carolyn · April 26, 2017, 08:45

How are you getting on with this one?