Front end noise when braking....

[s1mon]

I have a W124 E280 '95 Estate which has covered 150K. The car has been serviced to a high standard all its life.

I have just returned from a trip to Merseyside with the children, roof box and all. During the trip, I noticed a grinding sound eminating from the N/S/F when breaking reasonably sharply (typical M1/M6 style!)

The car has new discs and pads all round (5 mths ago), so it's not pad wear. It feels/sounds as if the shock absorber is grinding (when the front end dips slightly when braking at speed). I have tried pushing on the front wings and no sound is heard, so could it be the shock absorber considering the forward motion and weight shift when braking at 70mph??

Considering my thoughts, I had two front tyres fitted Thursday and the tracking adjusted, could it be a loose nut allowing movement? Mmmm...

 

[eric242340]

I have a W124 E280 '95 Estate which has covered 150K. The car has been serviced to a high standard all its life.

I have just returned from a trip to Merseyside with the children, roof box and all. During the trip, I noticed a grinding sound eminating from the N/S/F when breaking reasonably sharply (typical M1/M6 style!)

The car has new discs and pads all round (5 mths ago), so it's not pad wear. It feels/sounds as if the shock absorber is grinding (when the front end dips slightly when braking at speed). I have tried pushing on the front wings and no sound is heard, so could it be the shock absorber considering the forward motion and weight shift when braking at 70mph??

Considering my thoughts, I had two front tyres fitted Thursday and the tracking adjusted, could it be a loose nut allowing movement? Mmmm...

Look at your front Discs, are there any lines on them? Answer this first and we go from there.

 

[s1mon]

Thanks for your reply, I ran my fingers across the discs enroute and there is no sign of scoring.

Regards

Simon

 

[eric242340]

Thanks for your reply, I ran my fingers across the discs enroute and there is no sign of scoring.

Regards

Simon

OK, then look at the following. back plates, calliper bolts not tight, and as you have just had the discs/pads changed, I would suggest this is the first port of call to check out. And another angle is do you have any shaking on the steering wheel when this happens? I know this may seem like simple stuff but to find the problem takes patience.

 

[s1mon]

There is no shaking under braking.

Thanks

Simon

 

[eric242340]

There is no shaking under braking.

Thanks

Simon

Thanks for your reply, I need to go to bed now, but I will keep this on my brain and keep thinking, good night.

 

[Parrot of Doom]

A continuous grinding with pressure on the brake pedal, or a short grind as the nose dips down only?

 

[television]

A continuous grinding with pressure on the brake pedal, or a short grind as the nose dips down only?

This is an odd one Parrot, funny thing that I have heard of people getting something stuck in the disc, this happened to me in my V70R last week, the grinding noise when braking. I stopped the car and put it in reverse and braked and it went away, no doubt a stone.

 

[BarryG]

Just about to post on a thread myself. Happened to me today, grinding grating noise whilst breaking. I then heard it when I wasnt breaking ??
So went to a local supermarket car park and threw the car around and listened. I noticed it was noisier on right lock. Got my son to turn the steering wheel whilst parked and it was the power steering. Mine doesnt have a dipstick so unscrewed the top and the fluid was well below the minimum.

 

[s1mon]

Thanks for you reply(s)

In answer to Parrots question, i get a continuous grinding with (more than average) pressure on the brake pedal.

Best regards
Simon

 

[television]

I think that if you jack the car,first one side and spin the wheel applying the brake you will see what side it is, then on the offending side slip the wheel off you will see what is wrong.

It cant be anything to do with the shocks, and must be something stuck in the pads.

If a wheel bearing was lose, is the disc touching the back plate or is the back plate bent. A lose wheel bearing is checked by rocking the wheel.

 

[eric242340]

In my opinion, its the brake pads. They have a high metal content and need to be roughed up. Remove the pads and rough them up with very coarse paper. by that I mean emery or very rough wet and dry paper. Also take a file and run around the edges of the pads (putting a slight taper on the edges. I say this because you changed the pads but not the discs. A small stone caught between pad and disc is common too, so this proceedure will help also.

 

[eric242340]

Sorry, this post is a little old and I forgot you changed the discs as well, but the proceedure still applies. Try this and then see how it goes.

 

[television]

In my opinion, its the brake pads. They have a high metal content and need to be roughed up. Remove the pads and rough them up with very coarse paper. by that I mean emery or very rough wet and dry paper. Also take a file and run around the edges of the pads (putting a slight taper on the edges. I say this because you changed the pads but not the discs. A small stone caught between pad and disc is common too, so this proceedure will help also.

I have never heard in my life that you ruff up brake pads, what for ?

 

[eric242340]

I have never heard in my life that you ruff up brake pads, what for ?

I cant speak for UK, but here(unfortunately) its common practice. Too many fake parts, pads with a high metal content cause squeels. And it is possible these parts are arriving in UK.If they squeal, then we take them out and rough them up and that normally works out fine for a few thousand km. I hope im wrong and your not getting fake parts in UK.

 

[television]

I cant speak for UK, but here(unfortunately) its common practice. Too many fake parts, pads with a high metal content cause squeels. And it is possible these parts are arriving in UK.If they squeal, then we take them out and rough them up and that normally works out fine for a few thousand km. I hope im wrong and your not getting fake parts in UK.

It is the greasing of the rear of the pads and plates that stop squeaking caused by resonace.

 

[Bolide]

Did you fit MB or pattern discs & pads? If they're non-MB pads I'd chuck them away

I suspect you have a bad wheel bearing, or one of the front discs is warped, or the pads are glazed

Do you get any steering wheel or brake pedal movement or vibration at the same time as the noise?

Nick Froome
www.w124.co.uk

 

[hmang]

just a long shot but

when the front spring broke on my 210 it pinged outwards and then lodged itself on the wishbone against the shock
this made a grindy noise under braking as the spring rubbed against the shock when the suspension compressed.

or
could something have got wedged in between the disc and the silly tin shield

or
could the disc carrier be fouling the disc if perhaps the new disc is further in or out than it should be

or
none standard wheels fouling the caliper

or
caliper bolts too long fouling disc

might not be the worst idea to remove and refit the disc and pads to make sure the fitting is tickety boo

 

[s1mon]

Thanks, I am overwhelmed by the response!

I purchased the discs and pads from 'German, Swedish & French' a well known UK retailer of pattern parts.

I do have brake squeal by the way!

I will have to drop the car into a local garage (used beforehand) and have it checked out whilst I am at work- I simply don't have the time at present to investigate it myself.

On a different note, I had a blocked drain hole (NSF) near the battery. I had to remove the inner wing lining and the the drain pipe from beneath. A very simple job, even for a novice. I had heard that MB dealers would charge in the region of £500 to clear such blockages.

I'll leave a posting once I get to the bottom of the grinding noise.

Many thanks

Simon

 

[hmang]

gotta be worth a look at barry g's fix for his problem