latest problem - abs

[alan13henderson]

hi
Got the slight judder problem just before you come to a complete halt at very low speeds. Its obviously ABS deciding top kick in. No lights to say that though. Cars brakes well and straight.
Actions taken so far;
New disks and pads all round, didnt really expect this to be great help but disks were in a bit of a state. No difference
Disconnected ABS sensor on front, ABS light comes on and problem goes away. Guessing ABS is disabled at this point.
Fitted new ABS sensors to the front(hands still grubby from last night!). No difference.
Guessing next port of call is wheel bearings/hub? Ignored rear sensor so far.
Any(cheap) words of wisdom from out there?
ta

 

[jcasey007]

did you clean the crap out of the toothed ring in the hub?

pain to do with a small screwdriver but if they are the original hubs there will be a build up of grease and likley to have metal bits in it.

cheers

Jim

 

[alan13henderson]

hi
yep there was grease in there between some teeth - not huge amounts but guessed it was wheel bearing related and was normal.
Oh well wheels and calipers off again! Im good at it now, reckon on disks and pad change in 15mins a side if rushing.
ta

 

[jcasey007]

you will either need a nice cup of tea or valium when you do the teeth as there are about 270 (yes I counted them)

while you are at it check for execive play in the bearing in case the play is widening the gap between the teeth and the hall effect sensor

have fun

Jim

 

[grayt@lineone.ne]

Jim.
What would happen if one removed the sensor from the hub but still kept it connected? Would the light come on? I would have thought that the abs computer would still "see" the sensor as being in circuit. Or could a small lead with a suitable resistor around the 400 ohm value or the same value as a front sensor be made up to switch between the 2 front sensors to try to identify which side is causing the problem [pulsating pedal],what do you think?
Cheers.
Graham

 

[jcasey007]

fitting a 400 ohm resistor won't fool it as the ABS computer is looking for an inductive pulse from the sensor.

As for taking out the sensor, not sure, but if there is no pulse coming from the one sensor, the computer may think that the wheel is locked up compared to the other two sensors so odds are you will have the same symptoms

The one thing that might fool the computer is to run the two front inputs from one good sensor (in parallel), ABS won't work if you skid but may solve your problem

 

[alan13henderson]

definate play in drivers side hub.
Bought 2 new from USAutos on ebay - £195 inc shipping, full hubs, bearings and ABS sensors. Now will have 2 known good sensors as spares!
Expecting the 3 * 15mm bolts holding hubs to be well and truly siezed.
Sprayed heavily with WD40 when did the sensor replacements but expecting trouble or am I worrying about nothing based on others experience?
Any magic views on removing these - not much clearance for big levers etc?
Impact wrench?

 

[Ilikemice]

I found them pretty straightforward. The only problem I had was not having a socket/extension combo the right length to clear the CV joint. I had a long-ish socket and a too long/too short extension. It was a pain trying to work around it, and would have been even easier to undo everything with the right length tools!

My Explorer is fairly rusty under there but those bolts came out nicely. Come prepared with a long cheater bar though

 

[alan13henderson]

new hubs fitted no real problems.
15mm bolts came out easily with 2 foot lever, 32 mm driveshaft nut took a 6foot piece of scaffold pole extension but done.
Had been worried about these and almost paid a garage to do it!
ABS problem resolved!
Thanks for all comments

 

[grayt@lineone.ne]

hi.
glad everything ok, i looked at my hub bolts [well rusted] and decided to leave well alone, got another sensor off a forum contributor and it worked a treat [1st. one from scrapyard tested ok but must have been faulty], just goes to show. however i will remember your experiance with the hub bolts,not as difficult as they look. cheers.
graham

 

[grayt@lineone.ne]

jim.
sensor arrived ok, many thanks and guess what! it worked perfectly. goes to show that the one i got from scrapyard tested ok but didnt work [fixed the light on but still pedal vibes] there must have been something amiss with it .once again many thanks, if i can do anything in return let me know.
cheers.
graham