Is this normal?

[dokalj]

Hi all,

I recently decided to rock the car using the roof bars and to my surprise I hear the suspension making a screeching noise.

Does anyone know what this could be? It is more pronounced at the back and I get more noise from the rear OF/S, not so much noise at the front although I think it would be hard to rock with the engine weight.

Any ideas?

Thanks

 

[dokalj]

Another point to add, I think the handbrake needs adjusting because I have to push my foot all the way down on the foot operated hand-brake. Also when I get out of the car it makes a similar noise to the problem above. Furthermore if I put my weight on the inside of the car door it makes that noise.

Could it be the drop link between the anti-roll bar and the lower wishbone?

 

[grober]

Thought you got the ARB drop links replaced? Maybe need adjusting- Would have to be tightened/adjusted with the car resting on its wheels?

 

[dokalj]

I had the rear passenger one replaced, that makes a lot less noise compared to the otherside.

 

[stwat]

My 190 used to exactly the same before i adjusted the handbrake. It was the handbrake shoes moving inside the hub ever so slightly and causing the screeching noise.

The noise went as soon as the shoes were adjusted correctly.

 

[dokalj]

How much could this cost to correct? Is it normal for maybe one side to screech more than the other?

 

[corned]

I'd go with brake shoe adjustment as well. The noise is created by the shoes slipping slightly against the drum surface. If the brake was on tighter, the shoe would hold and there wouldn't be this slight movement which causes the noise.

You can get the same effect in a perfectly well adjusted set up if you don't apply the brake quite hard enough and rock (or push) the car. As the suspension moves (compresses and decompresses) with the movement you put into it (either rocking from outside, or just getting in or out of the car) this releases tension from the suspension and causes a slight turning action between suspension arm and wheel.

Cost to correct? Nothing if you can get under and wield a spanner!

 

[dokalj]

Could there be the possibility that the shoes need replacing?

Do you know if it is just the case of getting under the car and adjusting or does the hub have to come off the wheel?

Thanks again corned!

 

[dokalj]

I forgot to ask is it normal for one brake shoe to be adjusted differently compared to the other side? Say the N/S rear compared to the OF/S rear?

 

[corned]

Without actually having a look at it, I could not say for certain.

Another thing to bear in mind is that a build up of brake dust in the drum could cause the same issue.

If one side is worse than the other, is one side binding slightly perhaps? In theory, park brake shoes should never ever wear out, but small problems such as above will cause some wear.

You won't really know until you (or someone else) goes under and has a look. Start at the drum and make sure the shoes are in good order and clean. Check the adjustments there. Then look back along the cable mechanism to see if improvements can be made there.

 

[grober]

Have a look at all 3 diagrams here. çàï÷àñòè Mercedes: êîäû çàï÷àñòåé ìåðñåäåñ The parking brake shoes operate inside their own drum which is part of the rear disc assembly. They are 2 opposed shoes with an activating mechanism at one end and an expanding toothed wheel adjuster at the other. Clearance is normally set by turning the adjuster wheel thro an access hole in the drum. They should normally centre in the drum so both shoes bear equally on the drum inner surface. They are held in alignment and return to the off position via springs stretched between them. Some times these springs break and can cause similar problems to yours.You can try to adjust the shoes via the toothed adjuster- its very tricky to do this correctly without a lot of trial and error. Next thing is to remove the rear disc and caliper and examine/repair/replace any worn components.

 

[dokalj]

Cheers corned and grober!

 

[BlackC55]

Whan was the car last serviced? The parking brake travel should have been checked and noted then. The travel does not just appear overnight!

 

[paulrstaylor]

Maybe a silly question but does it make the noise without the parking brake applied (i.e. in Park or left in gear to stop it rolling away!)??

 

[dokalj]

Whan was the car last serviced? The parking brake travel should have been checked and noted then. The travel does not just appear overnight!

I am shocked that a lot of items were missed out on the service I had, especially my gaitor being torn when I asked them to adjust the tracking!

 

[dokalj]

Maybe a silly question but does it make the noise without the parking brake applied (i.e. in Park or left in gear to stop it rolling away!)??

I tried this and when left in park without the handbrake the car rolls slightly and realises it is in park and stops, no noise. Although I noticed with the handbrake I have to really push it hard possibly 10 clicks to be sure that it will hold the car. Does this sound as if the shoes need adjusting or the pedal? Or is it too hard to say without looking at the car?

 

[jefrs]

The drum adjust sets the centring of the shoes in the drum, if there is an adjustment cam it sets the off position so less cable pull is needed to operate: take up the slack on the pedal cable at the U. The cable probably runs from one drum to the other and is on a U stirrup which should balance them, these stick so copper-ease is your friend. The only real adjustment is the pedal cable which pulls the U, that should also reduce the number of clicks on the pedal.

There should be no wear on the parking brake because it is not used in motion. Because it is used so little these things fill up with crud and strange noises. Using it a few times whilst in motion is wrinkle for cleaning and centring the shoes. If the shoes drag they get very hot.

 

[jefrs]

error

 

[jefrs]

I am shocked that a lot of items were missed out on the service I had, especially my gaitor being torn when I asked them to adjust the tracking!

Shocked but not surprised: the last service we had done on the Corsa by the Foxhole dealer failed to notice that there was no antifreeze in the radiator.

Stealer (having obsequiously got my money), "here's your car, sir"
Victim (stressed after being violently parted from money), "thankyou, but why is it making a noise like a bag of nails?"