Parking brake will not latch

[DSM10000]

The parking brake on my 2003 W203 has never worked correctly since I have had the car, it has always been reluctant to disengage. Now it will not latch when I press the pedal and the pedal requires more effort to depress than before

Is there a common cause and simple home remedy or is it a case of giving it to my indie to look at?

Thanks in advance.

 

[DSM10000]

Any ideas ?

 

[silver_star]

Do I take it that it is "working" just you can't hear the ratchet mechanism?

 

[DSM10000]

No as I stated it will not latch and requires more pressure to depress the pedal, it is not the clicker, that was replaed last year but it would engage prior to that and after. There has now clearly been a failure somewhere as the brake will not engage and stay on.

 

[paresh]

Parking brake pedal not staying down

Did you manage to get this problem sorted?

My W203 has now developed the same problem. The parking brake will not stayed latched on. I can depress the pedal and can hear the clicking noise/rachet mechanism as the brake is applied. The parking brakes are applied and do hold the car stationery. However, when I take my foot off the parking brake, it springs back up and the parking brakes are released. Also the parking brake release handle in the dashboard has also become "floppy" - it feels as if there is no tension in the cable.

I've removed the dashboard end near the drivers door and can see that the release cable is still attached to the release handle. I removed the cable from the handle and can confirm that it appears not to be broken at this end at least. I can pull the inner part of the cable and it still feels attached at the pedal end.

So it appears as if there is something amiss with the parking brake pedal.

Has anybody experienced this problem and managed to rectify it?

 

[DSM10000]

I have not had time to look / get it looked at as yet. Mine is slighty different as the release is now stiff to operate so seems the opposite of yours.

 

[DSM10000]

Just to update this.

It turned out that the mechanism was faulty. The spring that grips the drum assembly in the parking brake had worn grooves into the metal and was jamming.

The part was £103 from Mercedes, not bad for a fairly large casting but labour to remove and refit was 3 hours. Not sure how complicated it is to replace but at least the brake now operates correctly. Total invoice was £303 parts, labour and VAT.

 

[BlackC55]

This is quite a common issue. No need to replace the pedal mechanism. Just extend the spring and it works everytime. 1/2 an hours work.

 

[DSM10000]

This is quite a common issue. No need to replace the pedal mechanism. Just extend the spring and it works everytime. 1/2 an hours work.

Thanks Olly, my MB specialist said that he had thought of doing that but he then read the MB workshop info that said on no account must you alter the spring!

 

[clarke77]

Hi I have the same problem.
Any chance of part numbers?
I take it that its some where inside the drums at the wheels.
Thanks

 

[DSM10000]

Hi I have the same problem.
Any chance of part numbers?
I take it that its some where inside the drums at the wheels.
Thanks

No, I beleive you may have misread my post. It is the foot operated part of the parking brake system I had replaced not the actual braking components which, as you say are contained witihn drums inside the rear discs.

As it was explained to me: The parking brake pedal assembly has a large and powerful spring which releases its tension as you press the pedal, this allows the assembly to rotate and this in turn pulls on the brake cables that operate the shoes in the rear drums.

As the pedal assembly moves it operates a against a ratchet, as you release the pedal the spring then contracts, grips and holds the brake pedal against the ratchet and therefore maintains the tension on the cables hence keeping the rear brake shoes in contact iwth the rear drums.

If you need a pedal assembly go to Euromerc, Nick had one for sale at half price. It may also be that your rear brake shoe adjusters are siezed, this is quite common or that the cables need adjusting.

 

[scottydee]

I have a slight problem in that the parking brake works but there is no ratchet sound. (There was at first)
Any ideas? The brake works so i don't know if its just gone quiet!

 

[DSM10000]

I have a slight problem in that the parking brake works but there is no ratchet sound. (There was at first)
Any ideas? The brake works so i don't know if its just gone quiet!

The plastic clicker has broken and / or fallen off. It does not affect the operation of the brake, the part is very cheap and easily replaced if it bothers you.

 

[scottydee]

Thanks! I'm not too bothered about the click. As long as the brake holds!

I take it that the click has nothing to do with a ratchet that holds it like a normal 'handbrake'?

 

[DSM10000]

Thanks! I'm not too bothered about the click. As long as the brake holds!

I take it that the click has nothing to do with a ratchet that holds it like a normal 'handbrake'?

It is just an audible indicator, it has no other function.

 

[Stratman]

Can anyone provide a part number for the spring in question?

I realise it's not necessary to replace it, but it helps when looking at the diagrams.

 

[DSM10000]

Can anyone provide a part number for the spring in question?

I realise it's not necessary to replace it, but it helps when looking at the diagrams.

My specialist told me that MB specifically say not to undo the clamp on the spring so I doubt it is listed as a separate part?

 

[clarke77]

Thank you
DSM10000 for your quick and very helpful reply.
I will check out the adjusters when she finally arrives in Oz been to long without her.

 

[DSM10000]

Thank you
DSM10000 for your quick and very helpful reply.
I will check out the adjusters when she finally arrives in Oz been to long without her.

Good luck.

Also be aware that there is a connection under the rear seat (easily removed) where the single cable from the parking brake assembly splits and runs to the individual drums. This can often need adjusting and / or lubricating.

 

[Yogi bear]

Mines just done the same as in this thread.

It's holding but when I take my foot off the pedal it doesn't hold down. The ratchet sound is still there and it does apply the brakes but just doesn't stay down.

My friend who works for MB fixed it within literally 2 minutes but Sod's law he's in Australia right now! He did say its easy to do but hard to explain.

Has anyone got any idea's?