Jump to content

ABS Brake failure!!!


keithjh
 Share

Recommended Posts

Hi All,

Yesterday fitted a new swivel hub to ther wifes disco, 300tdi Auto 1997, no problems other than the ABS light stopped on (see post yesterday).Tried vehicle brakes working fine.

Anyway wife went off to work tonight, just phoned me in a panic. Brakes have failed, she said when she pressed brake pedal went to floor with a knocking through pedal (ABS Activating?), anyway after getting it to a stand on a grass verge, she noticed ABS light was out, and when she decided to slowly move truck to a safer position, light came on and she has brakes.......any ideas

Keith

Link to comment
Share on other sites

I'm not sure what is wrong but I can tell you that I have had a similar problem for the last year or so.

It started with the ABS light coming on and the system activating any time I applied the brakes. Just as an aside I thought an ABS was supposed to stop you better than not having one. Well that was not my experience. I was told by my mechanic (ex) that is was the CV joint. I had both of them replaced but the ABS light stayed on. Much the same way as yours does. What I eventually discovered was that the wheel bearing was not as tight as it should be and consequently the sender unit was misreading the info from the teeth on the CV joint.

My problem didn’t stop there of course. I am now told that the ECU for the ABS is now shot and I need a new one to turn the lights off. BUT THE BRAKES WORK PERFECTLY NOW so I am loath to fix them.

If anyone else has any thought on the matter I would be delighted to hear them

Regards

Hugh

Link to comment
Share on other sites

Its just an ABS issue - I've had it myself. One of the sensors is out of adjustment - its as simple as that. Mine did the same thing after replaceing a CV joint and it was pretty scarey - the solution? I just pulled the sensors out, cleaned them up and then refitted them, but with a bead of silacset around the top to 'seal' them in place, left it to cure for 24Hours and its been fine since..........

For some reason, at times the ABS warning lamp can be on, but the system remains active and will trigger at the slightest bump in the road - best thing to do is to remove all of the fuses/relays/fusible links for the ABS system and it'll stop acting up for as long as it takes to fix the sensor air-gaps properly......

Discohere - how have you read the fault codes on yours and what year is it? My '96 300TDi gives odd codes from the OBDII socket, but has no blue ABS only socket so I imagine yours could be the same - I get codes that dont even exist out of mine when read, which folk often interpret as a duff ECU, when in reality its just the proceedure or the list of codes they are using is wrong! I'd pull all of the fuses etc for the ABS, go round and tap all of your senders back into place, re-fit the fuses and take it for a drive. it may well be OK - if not try pulling away, get into second gear above 10Mph then dipping the clutch and turning off the ignition and very rapidly turning it back on - the ABS warning lamp will 99% certain go out - if it does it means that the air-gaps are still not quite right, (there is not enough voltage being produced at the 'test' speed of 7-10Mph, but above that there is - the ECU will sense this as a fault and not enable the system, but switching the power off above the 'test' speed will fool it into thinking all is well) - and there cold be many a reason for that such as bearings, axle tube end bushes, CV joints, worn out sensor bushes/seals etc, etc, but it at least proves that the ECU is sound......... I have to do this on mine every-now-and-then as my rear sensors are prone to moving, even with new bearings correctly adjusted....

Oh and I've still to find a list of codes that tally's with the codes mine puts out and I've still to find a reliable OBDII reading sequence for the 300TDi as I'm not convinced the one I have is correct due to the daft codes it puts out.......

Hope I've helped someone..........

Link to comment
Share on other sites

Its just an ABS issue - I've had it myself. One of the sensors is out of adjustment - its as simple as that. Mine did the same thing after replaceing a CV joint and it was pretty scarey - the solution? I just pulled the sensors out, cleaned them up and then refitted them,

Took the sensor out gave it a clean refitted it, "slight" tap with medium hammer ;) and all is fine, light goes out when it should.

Regards

Keith

One of the times when a bigger hammer makes it fit :lol:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy