Hydraulic clutch problem

[AJT]

Hi All,

I've a hydraulic clutch release fitted with a 5 speed box. I'm having to pump the clutch peddle to get the system working. If I hold the peddle down it down, pressure doesn't appear to fall, but within 10 seconds of releasing, subsequent use requires a few pushes. There doesn't seem to be any obvious fluid leaks. Any ideas? Am hoping it's not the master cylinder as it's only two years old.

Have bled the system and no air is emerging.

Thanks
Alan

[bmcecosse]

Sounds like an adjustment problem - rather than air. There obviously isn't enough oil being pushed through on a single stroke of the pedal/master cylinder to hold the clutch out - by pumping it - you're getting more oil through. Look to see if there is any 'lost motion' in the mechanism. But it may just mean the clutch is now too worn to function with that master cylinder. May be you need a larger bore master - to push more oil in the single stroke - or a smaller bore slave to move further with the oil that the master is pumping. !

[AJT]

Thanks - I'll check that. I've just had the car on ramps for a couple of days whilst changing the brake master cylinder and wonder if I upset something whilst fiddling around as the clutch master is attached to the chassis rail, parellel to the brake cylinder (location a garage put it in which made getting the master cylinder bolts out a real knuckle nightmare!).

[jonathon]

You do have a header tank don't you??

[AJT]

Solved! a weird one this. The clutch issue arose whilst the transmission tunnel was removed (to replace the brake master cylinder - I like lots of access!). With the floor removed, the clutch peddle can rise further than normal, allowing total loss of pressure in the system each depress. With the floor holding the peddle down in it's normal position all works perfectly regardless of time between usage! This also explains why, when I originally got the car back from having the hydralic clutch and 5 speed installed, the clutch was so badly adjusted (i.e. far too much movement causing it to rub) - they had obviously had the same issue and adjusted with the floor removed rather than will all in place.

Alan

[bmcecosse]

Ahh! Odd indeed - point for others to note for the future.