W639 Vito clutch normal?

[Rocketdan]

Hi all.

I have a W639 Vito that has the symptom of the clutch peddle being heavy after continuous high speed driving e.g. coming off a slip road where it is only heavy on the first press and fine on the second. The pedal sometimes goes back to being hard on the first press when finishing work after being left for 8-10 hours with it being fine when parking up. Not long after buying the van I had the brake fluid changed and didn't notice this problem before. Are the two systems connected and could the brake fluid change have caused this problem with air being in the system after being improperly bled? I've read on other non MB car forums when googling the question that it is normal and part of the design and others saying the thrust bearing is at fault. Previous owner had towed with the van so maybe the clutch is worn. Any one else with a W639 Vito have the same symptoms?

 

[StMarks]

I don't have this problem with mine Rocketdan, but fwiw I can confirm that the hydraulics do share the same reservoir, as I have replaced my fluid a couple of times now, and I removed the clutch slave cylinder at one stage (when working on my gearbox).
I do recall being warned not to get air trapped in the clutch slave cylinder, and your symptoms do sound a bit like it may affect it.
The clutch has a dual mass flywheel system, don't know if the symptoms also point at an issue there.? (there are plenty of knowledgeable members on here who will know about DMF issues though).
Hth

 

[Rocketdan]

Thanks for the reply StMarks yeah deep down I had hoped that this was normal now money needs to be spent. There must be air in the system or a problem with the fluid as it only started doing it after a brake fluid change. The symptoms correlate to thermal expansion in the clutch system so maybe i'll get another fluid change and make sure they bleed the entire system as when I had it done at the garage I had given them a list of things to do so maybe weren't thorough bleeding it.