ABS Problem MG ZT-T

[larryr123]

Harry, I'm glad of the positive feedback on this board, but I think suggesting that someone is "chucking parts at something" and "running around in circles" and "not undertanding ABS" is wide of the mark.

I've wasted no money on my efforts in this instance, and everything I've done has been fairly logical. I think perhaps reading through the sequence would help that :-

1. Having ABS and speedo go, I replaced the sensor which restored the ABS and the Speedo.
2. On experiencing the pulsing on the peddle I took it to Souls - a recognised MG Rover dealer and service garage. They ran T4 static and took readings with the car in motion. No recognisable fault and the garage couldn't tell me where it might be.
3. The garage indicated that 90% of these faults occured on the back wheels and suggested cleaning up the back plates. I did this and replaced one of the hubs that was leaking -- not expensive or particularly time consuming.
4. Using this forum I worked through the chalk test, being careful to acknowledge that the ABS system adopted Hall Effect (magnetic sensitive) sensors that should not be addressed via a resistive method.
I did this in all 4 wheels with an analogue meter and then again with a digital meter to try to increase the accuracy. Both did not clearly identify dropped pulses.
On both occassions I was also caraful to ensure that a voltage was present back to the ABS controller.
5. On the suggestion of many on this board, the ABS controller plug was considered a potential problem if water logged. I took the battery components out and checked the plug was in fact dry and then carefully cleaned all the terminals to ensure no rust was present.

All the other expense was not related to the ABS problem as follows:-
4 new tyres and 2 new discs/pads were necessary as they were all showing clear signs of wear. The rear spring was an MOT failure and needed to be changed -- again I changed this and it was not expensive - again not necessarily related to the ABS issue.

So without continuing further with this discussion, I think it's important to recognise that I do have a reasonably good understanding of the problem, that no parts have been "chucked" at this problem and that it was not clear from a T4 test that this was an easily identifiable issue.

I think my comments are justified here as so many others have experienced difficulty with low speed ABS judder and there are few difinitive and easy to point to tests that resolve it.

Larry -- Enough on this

[Mike Noc]

Looking forward Larry Brian is spot on - Phil T4 is by far your best option for the most cost effective fix, and he is only around 10 miles or so down the road - or I should say along the road as he is pretty much due west of you.

[marinabrian]

Originally Posted by larryr123

"So stop messing about trying to repair it yourself, it would appear you are out of your depth and running around in circles "

Quite the little charmer aren't you Brian.
I wonder should you be in business at all with an attitude like that.

Both the T4 users were recognised garages, one with a good history of selling and servicing Rover and MG cars.

Larry

Larry, it may surprise you that I'm not in the business of repairing cars, I couldn't make money doing that as I'm too slow and meticulous to do so


I do however recognise that a comment from someone who dismisses a diagnostic system specifically designed for diagnosing your car as "useless" is someone who has not employed the services of someone who really understands how these cars tick

The problem is simple, these cars have been out of production for 12 years, the skill set that would have been commonplace 12 years ago among dealer technicians is forgotten at worst, or at best rusty, and your car will be viewed simply as an old banger.

Now Phil like many of the other enthusiast owner operators of T4, have a much more detailed in depth intimate knowledge of the inner working of your car than any former main dealer will ever have, hence my recommendation you contact him.

Brian

[HarryM1BYT]

Originally Posted by larryr123

Harry, I'm glad of the positive feedback on this board, but I think suggesting that someone is "chucking parts at something" and "running around in circles" and "not undertanding ABS" is wide of the mark.

I've wasted no money on my efforts in this instance, and everything I've done has been fairly logical. I think perhaps reading through the sequence would help that :-

From my reading of what you have done already in trying to resolve this, it certainly seems as if you are doing precisely that. You have paid for diagnostics and still not been able to get to the root of the problem.

You need to approach someone on this forum who has the experience and can help you avoid spending more money unnecessarily. As Brian has pointed out, the ex-main dealers might at one time have been up to speed on these cars, but with passage of time their skills and inclination to help become rusty.

[Graham1961]

Hi Larry.

I have to agree with the advice you are getting, Brian and Phil T4 are highly skilled with the T4 and i would recommend taking Brian's advice and contact Phil who will diagnose the fault very quickly.

The T4 is a proper MG Rover diagnostic machine and with a skilled operator will have no trouble fixing your problem...

[Phil-T4]

Thought i would update this thread, Larry came over today, i didn't use the T4 system as it has never shown up any problems before with this type of very low speed "peddle crunching" issue, instead i hooked each wheel up to an oscilloscope and watched the traces as the wheel was rotated.
Sods law always seems to dictate that (for me) it is the very last wheel that i test and sure enough, the o/s rear was showing 1 pulse missing.

Swapped out the bearing and the issue was cured in less than 90 minutes.

[Mike Noc]

Yes, and well diagnosed by Harry in Post #7.

[HarryM1BYT]

Originally Posted by Mike Noc

Yes, and well diagnosed by Harry in Post #7.

To be fair - A scope would maybe make it a little easier to spot the intermittently missing pulse, if the pulse is missed at a speed greater than it can be detected with a meter or my piezo sounder method.

It does bear out what I have said all along - that the T4 is not fool proof where the ABS sensors are mostly doing what they are supposed to be doing, producing mostly regular pulses.

Which wheel was it with the missing pulse, do we know? [EDIT] - got it OSR.

[Arctic]

I have said & seen this quite a few times, for some reason the OSR seems to be the trouble in quite a few cases including my own, I did say to Larry to plump for the OSR in post 54

https://the75andztclub.co.uk/forum/s...6&postcount=54

[Heddy]

2. Changed both rear hubs in 2014 and changed the rear nearside again this year. Also cleaned all rust off back plates.
I think this text from Larry was key. Amazing the amount of posts and views before it was solved.