High pitched Scream, squeal from the brakes?? when stationary.

[John77]

When you first get in the car, start it, put the brake on, then put it into gear. As you let the brake off there is an High pitched Scream, squeal from near the dashboard. Probably from the engine bay. It only lasts a second, but if you apply the foot brake, then let the brakes off very slowly you will get a prolonged squeal that only stops when you let the brakes off further. Not had chance to get someone to put the brakes on so I can look under the bonnet, but thought that someone on here would know.

 

[M80]

Vacuum leak?

 

[John77]

Vacuum leak?

Yes my first thought. I will have to get someone to help while I look. Thank you.

 

[brandwooddixon]

Which car is this on?

 

[John77]

Which car is this on?

2009 SLK200

 

[John77]

It seems to have stopped. Strange.

 

[ioweddie]

fan belt slip?

 

[M80]

fan belt slip?

A push on the belt to check the tensioner should diagnose that.

 

[John77]

A push on the belt to check the tensioner should diagnose that.

Thank you

 

[Altamar]

When you first get in the car, start it, put the brake on, then put it into gear. As you let the brake off there is an High pitched Scream, squeal from near the dashboard. Probably from the engine bay. It only lasts a second, but if you apply the foot brake, then let the brakes off very slowly you will get a prolonged squeal that only stops when you let the brakes off further. Not had chance to get someone to put the brakes on so I can look under the bonnet, but thought that someone on here would know.

I would suspect slight rust on the brake discs, especially as it stops when you touch the brakes (and gets longer when you gently release the foot brake). This usually comes from the back of the car more than the front though

 

[LostKiwi]

You may have a vacuum leak from the brake servo.

 

[John77]

I would suspect slight rust on the brake discs, especially as it stops when you touch the brakes (and gets longer when you gently release the foot brake). This usually comes from the back of the car more than the front though

The car is not moving. Put the brakes fully on nothing. Start to take them off squeal then as you go further, nothing. Add pressure squeal. Strangely not there today. Brakes function fully.

 

[John77]

You may have a vacuum leak from the brake servo.

Yes I thought that. I will have to investigate further with some soapy water.

 

[John77]

A push on the belt to check the tensioner should diagnose that.

How would applying the brakes effect the belt?

 

[M80]

Yes I thought that. I will have to investigate further with some soapy water.

But you wouldn't get the tell tale bubbles.

 

[John77]

But you wouldn't get the tell tale bubbles.

ok

 

[M80]

How would applying the brakes effect the belt?

I'm assuming your vacuum pump is driven off the camshaft??

If it's actually belt driven than the pump being loaded could cause belt slip.

 

[LostKiwi]

I'm assuming your vacuum pump is driven off the camshaft??

If it's actually belt driven than the pump being loaded could cause belt slip.

Petrol engine. Vacuum is drawn from the manifold on most cars.
Diesels have separate pumps for vacuum - often camshaft driven.

 

[John77]

Petrol engine. Vacuum is drawn from the manifold on most cars.
Diesels have separate pumps for vacuum - often camshaft driven.

Petrol.

 

[John77]

Well I think that I have finally found it. It seems to be coming from this joint. How does this pipe come off as it does not seem to just pull off?