ABS sender ring corrosion

[Lennart Sorth]

This isn't strictly an Espace issue - but as my Peugeot 406 Coupe has the same engine as the Espace JE 3.0 V6 24V, I think they share the driveshafts as well.

Driving back from Le Mans, I noticed that when touching the brakes while the car was almost stationary (at roundabouts or road crossings) it felt as if I had a cracked brakedisk. klonk, klonk,klonk - I quickly realised that it matched the revolutions of the wheel.

At higher speeds, there was nothing at all.

At one particular roundabout, the ABS light came on, but this was just before parking at Carrefour (the annual wine-run :-) ) - and when I started up again after shopping, the light remained off for the rest of the trip.

Now, back home I set about looking at my right front ABS sender ring and sensor, which I thought must be causing this (the disks are fine) - and lo and behold, I found the ABS sender ring quite corroded - strangely, much more than the left hand side.  (it is a RHD car, having spent most of its life in UK, so I would have expected the left side to have seen most water/grit/dirt)

Anyway, this had led to the poor thing loosing a tooth, and the remaining ring actually felt rather fragile - see attached picture.

Now, I hoped the ABS sender ring could be replaced, but I quickly learned that the only way this can be done is to replace the entire driveshaft - which was otherwise in very good shape - at an expense of 120£.

As soon as that was done, I "painted" the left hand side ABS sender ring with Hammerite "Kurust" - the stuff that turns FeO₂ into some black compund which I know from 8-10 year old applications on rusty parts of my Murena - is very effective at postponing rust.

The sensor works by hall-effect or susceptibility measurements, so it doesn't matter how you treat them - although I don't think anything sticky would be a particularly good idea.

For what its worth, if your car has ABS, chances are that it has such ABS sender rings, and they might survive longer if treated.

/Lennart

[Lennart Sorth]

I didn't think of it at the time, but I have now taken a picture of the treated ABS sender ring (left hand side, as the right hand side is now a shiny new driveshaft.

The black stuff looks wet - but isn't at all.

The ring was rusty - although not as bad as the RH side (where I ended up also treating the hub, as I needed somewhere to spend the rest of the Kurust I had poured up.)

/Lennart