brake pad wear indicator on after service
 

1992 Mercedes W124.

After replacing front strut and tightening steering wheel at a dealer,

I hear scraping sound when the steering wheel is at extreme position,

and now I see front brake pad wear indicator coming on.


Can brake pad sensor go out of order due to some mistake in such service?

If yes, I want to go to the same dealer for brake pad wear indicator.
If not, I want to go to independent for that.


(I did 15000 mile maintenance about 1.5 month ago. 15000 mile maintenance includes brake pad and disk inspection. The mechanic did not say anything about brake pad or disk except parking brake.)

did your mechanic replace the wear sensors?

No, he did not replace pad wear sensor.

What might be relevant are

1. remove airbag and tighten steering wheel (to remove metalic rattling noise from steering wheel).

2. replacing front struts

3. horn wiring (there were two electric connectors hanging in the air under the hood)

Either your pads are done or the wear sensor has been shorted. If the sensor wires have been disturbed and now no longer tucked under the metal tab they can be worn and shorted by the spinning wheel. Easy to check and sensors are cheap $1-$2.

Sounds like the strut work should be reexamined also.

glenmore
1991 300CE

Struts needs to be reexamined? I hope the dealer does not charge the new labour cost for the problem caused by the dealer's recent work.

The brake pad wear indicator is not always on.
It sometimes comes on, especially often during parking.

Probably no big deal. In the course of changing struts, it would be very likely that the sensors would be removed to get the wire out of the way. These things are very fragile, and break easily when pulled.

Also may not have been reinstalled properly, or wires could have been damaged in process. Sensor wire is secured with plastic clip on strut, and may not have been resecured properly. Anyways, none of this is a big deal. Worst case, you actually need a brake job...

Sounds like you have two problems. There is still a problem in the steering wheel hub, and you're pads are coincidently due to be replaced especially when the light only comes on when you apply the brakes. There is no reason to do anything with yhe brakes to change struts.

Peter

Kitlimq,

Well if the scraping sound was not there before, I would have the dealer check their work.

The brake wear sensor will be intermittent. Sometimes only when backing and braking, sometimes only in parking situations. Sounds like your pads are due. When the light first comes on, you still have plenty of pad wear left. Just pull your wheel off and take a look. The first tool you can get is a nice torque wrench!Follow the sensor wire into the pad and it will be obvious. The early warning just gives you time to get all your ducks in a row if you want to do them yourself. You need the parts, the tools and a little reading material.

Sounds like you are at the same crossroads I was at earlier this year. My DIY car repair experience was zero when I bought my 1991 300CE a little over a year ago.

You can either take your car in each time or you can try and do a lot of the easy stuff yourself. I changed the front brakes for about $150. That's nice new Balo rotors, Pagid pads, sensors and I repacked the front bearings also. That is probably over $500 at the dealer. Just changed the drag link the other day for $48. Indie wanted $115, dealer probably $150.

It is not entirely about the money as your time is worth something and tools are not cheap either. A lot of it is the satisfaction of learning something new and overcoming obstacles.

glenmore
1991 300ce

Thanks for your replies.

The scraping sound (when the steering wheel is at full turn position) magically became quiet in these couple of days. Dealer found no problem.

The dealer said the brake pads and rotors should be replaced and estimates the total cost to be about $550.
I postponed the job because I already spent apprx. $ 2k 1~2 weeks ago at the dealer, and am now out of money.

The dealer said that the transmission pan should be replaced.
Transmission pan "gasket" was replaced just 1~2 weeks ago at the dealer due to leak. But they said it leaked again this Thursday.
This time, they did not charge labour cost for transmission work.

Wow!
$550 is impressive.
Do you get all four corners for that, or just the front?

The dealer said the estimate was about $550 for FRONT brake pads and rotors.