Rover 75 abs problem


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By Administrator - 10/3/2004 6:25:14 AM
Hello

Just wondered if anybody could give me any ideas, I have a Rover 75 2.0 V6 1999. I have a problem where the ABS functions prematurely I get kick back through the pedal at any speed untill the ECU recognises there is a fault then turns off the ABS and puts up the warning lamp on dash, it also turns off the traction control. I have replaced the both front wheelsensors as advised by Rover after they put it on the T4 test book, but then said that no more fault codes are present and they are not sure what the problem is!!! I am at a loss and dont want to start component replacing at random. Any Ideas

Many Thanks
Craig
You may go into as much detail as you want.

This was added by a guest on the old forums
By Angus - 10/3/2004 6:32:43 AM
Craig

It would be too much of a coincidence, for you to have the same broken reluctor ring fault as Mij’s 416.

Wouldn’t it?  Worth a look?
By K And R - 10/3/2004 6:33:04 AM
Craig
   Before we go any further i know its not the same car but have you read the rover ABS post below on 416, it may have some relevance here also
Kevin
By Craig501 - 10/3/2004 7:11:05 AM
K and R / Angus

Thanks for replying!
Just been reading the 416 stuff which does seem to have some relevance, think I wil start by looking at the front rings just hope there are not as the 416, integral with the outer cv joint, is it true that the rear rings are in the form of the hub seal, the hub seal has magnetic poles imbedded??

Not sure but will have a look at the front and rear rings tomorrow and let you know, I will keep you updated.

Craig  Smile
By K And R - 10/3/2004 7:18:16 AM
Angus
 You beat me by one minute bu**er ;D ;D ;D
  Kevin
By Chuck_Wagon - 10/3/2004 10:00:58 AM
Just a thought here,

I’m not sure what system we have here on the Rover 75, anybody know?

Does this system utilise ’active’ wheel speed sensors?

If so, the wheel bearings themselves are going to provide the input to the wheel speed sensors, instead of the normal reluctor ring. Just to get you all thinking along these lines!

Craig,

Have a look at your front driveshaft CV joints, do they have a toothed ring on them, or not. If not, we are looking at active wheel speed sensors.

Also, has any work been done to the driveshafts, wheel bearings, hubs or suspension components on this car. Particularly wheel bearings, front or rear.

I have some more ideas on this, but let me know about these questions first.

Chuck
By Craig501 - 10/3/2004 10:36:07 AM
Chuck

There hasn’t been any direct work done to the driveshafts, bearings etc however I did the clutch at 72000 were I had to take the driveshaft out of the GearBox etc etc but not at the hub end, I am havig a look tomorrow so I can give you a little more info.

Thanks
Craig Smile
By Angus - 10/3/2004 11:03:20 AM
Kevin

Re. crossfire.  It was much tighter than a minute; two seconds after I posted, it refreshed and it had picked-up your post too.

How do we keep doing this?  Telepathy?  (Ring you soon; when I get a sec.)

Chuck

Good job you know all about these; I’ve got nothing on "active sensors" or Rover 75 systems at all.  (Somebody, please, wake up Autodata!!!)

If I follow correctly what I think you’re saying; there are spaced magnets embedded in the rotating hub periodically aligning with the poles of a fixed annular current-fed pick-up/coil a bit like the old distributor one’s.  Yes?   (Thought it had to be too much of a coincidence).



By Chuck_Wagon - 10/3/2004 11:27:04 AM
Angus,

You got it in one, that’s where I’m thinking.

Chuck
By K And R - 10/3/2004 11:51:55 AM
To all
 Will check my info on this as i just posted in haste to stop a long tread. i,ll be back
Kevin.
By Craig501 - 10/4/2004 9:08:22 AM
Well Gents

I read through your suggestions and took your advice and had a look this evening to see what is going on.
I found that on both front cv joints there was no Reluctor ring for the Sensors,
However!! what I did see was that the inner bearing seal runs adjacent to the side if the abs sensor head and to look closely there seems to be evenly spaced lines around the seal face, so I reckon that these are the poles that provide signals, and spookily enough the N/S/F seal is damaged looks as if there has been something trapped between the sensor head and the face damaging the surface, so I am going for this and fitting a wheel bearing kit new seal etc etc.

What do you reckon genuine Rover part? or an after market job? (QH for eg).

Craig BigGrin
By Angus - 10/4/2004 9:26:58 AM
Craig

Chuck was spot-on.  Active sensors.  For routine replacements you might consider non-gen; but for fault-test replacement it’s got to be known quantities, so dealer parts, sadly.

Any visible damage to the sensor head itself?  What do you think attacked it?  A stone or something metal?
By Craig501 - 10/4/2004 9:48:37 AM
Angus,

I will go for genuine, just got to bite the bullet eh! better to be safe then sorry or still scratching my head!!, well I reckon it could have been a small stone or build up of ingressed dirt or rust just not too sure , the head is ok though as I renewed the sensors as my first plan of attack a few week ago,
I will let you know how I get on when I have replaced the seal.

There is definately some experience at this forum!
Quality site.
Thanks a lot.

Craig
By Chuck_Wagon - 10/4/2004 9:53:50 AM
Craig,

Be aware that there will probably be two types of wheel bearing available. One for models with ABS and one for models without ABS.

If you get the wrong one it won’t have the polar rings imbedded in it, and the system won’t work (ie, we’ll be back to square one).

Also, when fitting the new bearing, if it is retained in the hub carrier with a circlip (which it probably is), make sure that the ends of the circlip align with the area where the wheel speed sensor locates. The circlip can disrupt the signal to the sensor if it’s not fitted correctly.

Basically, look at the position of the existing circlip (if there is one) before you remove it, and make sure you refit in the same position.

But what do I know Kevin, I’m not ’hands on’ ;D

Sorry Craig, that last remark wasn’t anything to do with you.

Hope you get a result and let us all know.

Regards,

Chuck
By K And R - 10/4/2004 10:04:44 AM
Chuck
    You probably know more that me as i,m only a grease monkey with ambitions ;D. but have been going through my data and if its right the magnets the sensor reads are in the bearing seal its-self.
If so Craig you will have to be very careful pressing in those bearings.
Kevin.
By Chuck_Wagon - 10/4/2004 10:17:33 AM
Craig,

Kevin’s absolutely right on this, be very careful. We are assuming you have access to a press here.

Please don’t be tempted to hammer the bearing in!

Kevin - I’m a grease monkey too, but just traded the grease gun for a pen some years back!
By Craig501 - 10/4/2004 10:25:46 AM
Chuck,

I’ve got access to a press no dramas, from what I can imagine I will be pressing fr0m the outside of the Hub to the inside, do you reckon using the old bearing to push the seal in or do have any other ideas??

Just hope that the hub comes off the strut OK as well, cant see this as ever comming off before!!

Craig
By K And R - 10/4/2004 10:28:43 AM
Chuck
    I,m useless with a pen, i use ie spell check all the time. And there are those that think i,m a useless grease monkey but life is too short.
 Kevin.
By Chuck_Wagon - 10/4/2004 10:40:47 AM
Craig,

I don’t know how experienced you are at overhaulling a front hub, but as you say you have access to a press, I’m assuming you are in the trade, or at least know the general procedures.

You can use the old bearing to press in the new bearing, but don’t let it jam in the hub as you do so.

Any other item will do, steel strip, mandrell, very large socket, etc, but it must only be in contact with THE BEARING OUTER RACE.

Let me know if you’ve done this sort of work before ’cause there are a few points to watch out for if this is all new to you.

Chuck
By Craig501 - 10/9/2004 10:02:10 AM
Hello There

Well I have managed to fit the new bearing (on Thurs), it was a bit of a cheeky job, the old bearing which does incorporate the ABS ring (all in one item)  was a right bugger to come out to say the least!! the hub itself the part with the splines inside, is also an interferance fit to the inside of the bearing so when I pressed that out it took half the bearing out with it, which then had to be angle grinded off the hub. However when it was all out the new one went in no dramas with a combination of large sockets and various old bearings, but like you mentioned I made sure that the Ring wasn’t touched.

Subsequently the warning lights are out and all seems back to normal. Doesn’t look as if I need to clear any codes either?

You give me some top advice and saved me some pennys too!! Many thanks to you all.

Craig
By Chuck_Wagon - 10/10/2004 10:20:17 AM
Craig,

Just glad we could help, and thanks for letting us know how you got on.

All the best,

Chuck