A4 wheel bearing changed... now the ABS light is on

[cliff2710]

Hello all, first Post here.

Ive just had a mechanic change the front offside wheel bearing on an A4 se estate, and the ABS light is now on, along with the flashing BRAKE warning light.... the mechanics response....

Yeah, that sometimes happens !!!

What is he likely to have done/ not done ?...

Thanks in advance.

[kenney]

Hi It has occured the abs sensor has been damaged when replacing the wheel bearing, But you need a fault code read on the brake system,to find the reason.

[Captain Answer]

Hello all, first Post here.

Ive just had a mechanic change the front offside wheel bearing on an A4 se estate, and the ABS light is now on, along with the flashing BRAKE warning light.... the mechanics response....

Yeah, that sometimes happens !!!

What is he likely to have done/ not done ?...

Thanks in advance.

ER.. why just one bearing? always always always do the same work on both sides of an axle

[cliff2710]

trust me, if i had the money, both sides would have been done !!

[kenney]

Hi (Why just one bearing? always always always do the same work on both sides of an axle) That! my friend is a load of rubbish.You do not change both wheel bearings,when there is nothing wrong with the other one.Springs, shocks, etc,yes,but a wheel bearing NO.

[hogiapesda]

never heard of having to change both bearings at the same time before. As stated yes shocks and springs but not bearings.

[GTW]

Just to reiterate the wise words of others, changing bearings as an axle set is utter tosh.

The ABS sensor can get damaged if it's not gently removed from the hub before the driveshaft is taken out. Potentially careless workmanship, although sometimes the sensor can give up the ghost just by removing it.

If it flags up a fault, it's obviously not co-incidence, but whether it was careless, or just doing to die anyway, who can tell.

C'est la vie - frustrating bad luck:(

Gaz

[Captain Answer]

BAHAHAHA righto chaps carry on, so if one bearing needs replacing due to wear then you naturally assume the other is fine and will keep on a spinning forever... meanwhile back in the real world

[GTW]

you naturally assume the other is fine and will keep on a spinning forever...

Not at all.

In the grand scheme of things, it's the nsf bearing that takes the most punishment in normal driving conditions.

Bearings don't wear evenly. There are too many other factors involved.

It's a fair bit of work to replace a bearing unit and signs of wear are very obvious, so why replace one that isn't showing those signs of wear if there is no need to?

Gaz

[Crasher]

hereketty, I am the most **** perfectionist knob that I know, I even drive myself potty but I would not replace both wheel bearings if one fails. Dampers, springs, discs yes-that should be law, but not wheel bearings. If one CV boot split and the other was OK, would you replace both? If one track rod end was worn or one rear caliper developed a fault, would you replace both?

[cliff2710]

OK, so assuming the abs sensor is duffed up a bit..... does this mean he now has to take the bearing off again to replace it ??
:aargh4:

[GTW]

Nah:approve:

It's straightforward enough once the wheel's off (you might even be able to do it without taking the wheel off).

But you really want to check the fault codes - no point in replacing it if it's not fubarred.

Equally, it might not register as working if it's not located properly (that's a guess - I don't know for sure, but if the other three are registering a rotating driveshaft and this one isn't, it's plausible)

Gaz

[kenney]

No

[Captain Answer]

hereketty, I am the most **** perfectionist knob that I know, I even drive myself potty but I would not replace both wheel bearings if one fails. Dampers, springs, discs yes-that should be law, but not wheel bearings. If one CV boot split and the other was OK, would you replace both? If one track rod end was worn or one rear caliper developed a fault, would you replace both?

Yes I actually would in all those cases, never do half a job :approve:

[Crasher]

Would you do that for a customer :confused: If you did, you would go bust!

[sparky6840]

BAHAHAHA righto chaps carry on, so if one bearing needs replacing due to wear then you naturally assume the other is fine and will keep on a spinning forever... meanwhile back in the real world

"In the real world" Bearings normally fail through no fault of their own, its normally an oil seal or other devise which upon failure allows dirt and water into the hub which contaminates the lubricant with harsh abrasives and it is this which ruins any bearing either roller or ball
Its this reasoning that we do not replace all bearings upon the first failure;)

[cliff2710]

so is the abs sensor something I can easily get from the local scrappy ? and how long is it gonna take me to hoik one off ??

[GTW]

so is the abs sensor something I can easily get from the local scrappy ? and how long is it gonna take me to hoik one off ??

Yes, with the wheel off it only takes a few moments. But how will you know that you have a working one?

I'd be inclined to get a new one if you're able to afford it.

Gaz

[cliff2710]

well, i cant afford a new one.... and i can say that confidently even tho i dont even know how much they are !!!! lol...
but my reckoning is that if I find an a4 in the scrappy's.... chances are its not there becasue of a faulty abs sensor.....

[Crasher]

They are £130 from Audi.

[adamss24]

£35 plus Vat for genuine Bosch one at Euro Car Parts if you ask for the best price !

[xpress52]

Hello All,

Just had the offside bearing changed today on my A4 as it was making a grinding noise whilst driving. The mechanic suggested I only replace the one that is worn out and not both, i was happy with the response as it can become expensive. Everything back to normal now - no more noise.:Blush:

[JohnyIre]

Not sure with A4's but I have heard of a Ford with a steel dust cover on one side and plastic on the other, mechanic put it in the wrong way and he got the same sensor problem. Swithed ot around and all was fine. Just a thought but potentially right and potentially useless!

[rhencullen1989]

I have had to do 2 nearside wheel bearings and 1 offside wheel bearing (and that was only because it was diagnosed wrongly at the independant that i use!). Its a bit of an *** of a job and i would not replace both sides unless they were both droning. As said before, the near side gets all the sh** and pot holes on the edge of the road, so inevitably things will wear out quicker on that side.:approve:

[jkay2008]

Hello all, first Post here.

Ive just had a mechanic change the front offside wheel bearing on an A4 se estate, and the ABS light is now on, along with the flashing BRAKE warning light.... the mechanics response....

Yeah, that sometimes happens !!!

What is he likely to have done/ not done ?...

Thanks in advance.

He may have spun the wheel with the ignition on, this can cause an apparent fault. You may be able to clear this by having the battery disconnected for a few minutes. (make sure you have your radio code)
If not, get the codes read before you waste any money/time changing a sensor.

Just to double check, did you fit a new bearing, or a second hand hub from the scrappy ?

[jkay2008]

Just to reiterate what others have said, changing both bearings on an axle at the same time is total baloney ! :D

[eyece]

Hi.

This has just happened to my Audi A6 1999. The red brake light beeps 3 times then the yellow ABS light comes on and the red light continues to flash.

What are you saying this is caused by and do you know how much it will cost to repair?

I've only just got my clutch and flywheel changed... £480! So I'm not in the mood to be splashing out again!

Thanks guys.

[jkay2008]

Hi.

This has just happened to my Audi A6 1999. The red brake light beeps 3 times then the yellow ABS light comes on and the red light continues to flash.

What are you saying this is caused by and do you know how much it will cost to repair?

I've only just got my clutch and flywheel changed... £480! So I'm not in the mood to be splashing out again!

Thanks guys.

Were not phsycic, and can only guess what is wrong without seeing it first hand. I have been called to a lot of abs faults were it turns out to have had a service or repair and had the wheel spun with the ignition on, and this flags a wheel speed discrepancy fault because the other wheels arent spinning at the same speed.
A simple code read will indicate the fault.

[eyece]

Thanks for the advise. I checked my brake discs and the rear ones are a little worn. They still have a few months left in them though.

[powellste]

im looking at replacing a nsf bearing at a local garage, any idea of a reasonable cost?

[adamss24]

If one CV boot split and the other was OK, would you replace both?
I had many instances when replacing one side cv boot gaitor and few months down the line the other will fail, also i allways(on me cars!) replace both track rod ends so i could fit the uprated ones with the bigger balljoints ! Reason is the tracking need doing anyway...Wheel bearings... No !

[Crasher]

It all hangs on how that top bolt comes out or if it doesn’t, the job can turn into a nightmare if it won’t budge.