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Aqua Puttana
09-24-2013, 03:05 PM
What tips do people have for removing a stuck wheel speed sensor.

My Sprinter lives in the road salt New York State. My 2004 sensor was siezed so badly that I gave up after I noticed that the sensor end had mushroomed a bit from my wedging against the tone ring (not a good idea by the way because you bend the tone ring). With that end deformed I know that it would not come out so I cut the sensor wire and then spliced it for re-installation. Cutting the wire may be my go to move rather than trying to remove a good sensor for future work.

Now that the end is mushroomed it appears to me that if I ever need to remove that sensor it will take drilling, ripping the induction coil guts out, collapsing the housing walls, and then pulling it out. I hope that the sensor doesn't fail.

What are some methods to try for the other undamaged ones should removal ever be necessary?

As an aside, I found the distance from the tone ring to the sensor to be about 15 thousandths using a feeler gauge. Re-forming the tone ring slots and re-establishing that distance, snug at times, to the tone ring works on my van. [12 thousandths might be the better target. I have had some very sporadic spurious auto wheel braking when creeping in traffic.]

vic

Boater
09-24-2013, 11:19 PM
I'm not sure if this will help.....

My drivers side one already looked damaged and was about 1/4" away from the tone ring. I wire brushed the rust and soaked it in penetrating oil. Tried wedging between it and the tone wheel to no effect so set about trying to find some kind of drift to punch it out - the drive flange and tone ring get in the way but I managed to get a screwdriver on it. From the resulting damage I can confirm that the shell is pretty thin and it won't be difficult to rip it apart should you need to! I then noticed a slight lip around the top so tried driving it out using the screwdriver on that, again it wasn't too hard to shear the lip off - however this was only possible because that sensor was so far out already, the passenger side one was correctly located so this was not an option.

In the end I managed to get mole grips onto it and wiggle it around gradually loosening it. After maybe an hour or so I finally got it moving and withdrew it, utterly mangled.

The passenger side one looked better and was positioned OK so I went straight to mole grips (or did I use water pump pliers to start with?) after wire brushing and soaking and managed to get it to wiggle out without any apparent damage. I need to replace both bushes and clean the holes up (think the bushes only come with the sensors) so I haven't tested it and will probably just replace it anyway.

Will make a note of 15 thou as a suitable clearance when I get round to reinstalling them - thanks!

MillionMileSprinter
09-25-2013, 04:50 PM
Heat.
Get a plumber's copper pipe soldering kit (or just the propane tank and torch attachment) and heat that baby up.
Not the sensor, but the solid casing around it. When replacing the leaf springs on my new (to me) Sprinter, I had to take heat to the rear end to get something loose (...can't seem to remember exactly what that was... but I remember using the torch...)
On a similar vein- did you notice how easy or hard it would be to remove the tone ring? I damaged mine in the spring swap by accidentally pushing the sensor down into it without knowing it. When I started driving, it all went to heck. The sensor came out fairly easily by prying on the top with a screwdriver when I replaced it, so i can't help you out there.

Boater
09-25-2013, 09:13 PM
Weird how subjects come in groups!

I decided against heating to remove the sensors as there are other wires and the brake hose in the general area - last time I tried to use a blow torch in situ was on my car's exhaust from pipe and I ended up melting some vacuum hoses......

Encountering the second tone ring question in 5 minutes I decided to go fetch my Haynes book - it says both front and rear need heating to 180 C to fit, which is the same as the front ones I did on my car. On my car the passenger ring was so rusted it was cracked, the drivers side was rusted almost to cracking, both were very brittle with age and rust so I used a cold chisel and didn't need to hit them very hard to break them and get them off. I then wire brushed the shoulders and cleaned them up with some emery cloth.
To fit the rings I set up some refractive blocks on my driveway to make a temporary hearth - I generally set them up to form a corner so heat is reflected back towards the centre. I set each ring in turn in the hearth and used my propane torch (roughly 1-1/2" nozzle) to heat until the rings started to glow (I hadn't found the correct temp or temp/colour relationship but I have had 6" diameter 1/2" thick steel disk glowing cherry red using this setup) - I did notice that a coating on the rings turned sort of yellowy at a temperature that worked, not sure if this is intended as a guide or just coincidence. Once the ring is hot enough pick it up with 2 pairs of pliers (or tongs if you have metalwork gear - I don't and pliers worked fine) and work quickly to slide it into place and pin it against the shoulder with both pliers - the cold mass of the hub will cool it enough to shrink fit it solidly in place within about 10 seconds. That is really all there is to it - easy if you have propane torch, welders gauntlets and ideally something to use as a hearth (BBQ pit might do it?).

If you don't get it seated right be sure to tap it off before it cools too much and heat up again - I had to do that with one of mine. Worst case scenario is you fail and have to chisel it off and buy another one. I really didn't want to try heating it in situ and end up destroying cables and the brake hose!

Gaspiping Sprinter
02-26-2018, 11:45 PM
While I was changing the front wheel bearings I decided to take out the ABS sensor just to see how difficult it was ! There's a copper sleeve between the sensor and the hole .
A 3/8s piece of wood and a hammer managed to push it right through .

Gaspiping Sprinter
02-26-2018, 11:51 PM
Took copper sleeve out and cleaned it and the Sensor with oven cleaner then did the same thing for the hole plus used a 1/2" plumbing wire brush .
Put all together ,went for a spin and it's all good .