Clutch problem.

[Simon]

the other day my GTD had lost all pressure in the clutch pedal. I put it down to it not having been used for a long time (9 yrs) and maybe air in the system. I bled the system and it seemed fine. Went out this morning, no pedal pressure but after one pump of the pedal there was full pressure. I went for a short drive but could feel the pedal loosing pressure (clutch biting point moving further towards the floor) and I just managed to get home. I put this down to maybe more air bubbles and decided to bleed the system again.
On taking off the front of the car, I could see a small puddle of brake fluid that seems to have leaked out of the vent hole on the master cylinder. Again no pressure in the pedal on the first pump. I bled it again to be sure, but there were no air bubbles in the system.
It seems like I may have a problem with my master/and or slave cylinders. Can anyone give me the part numbers for rebuild kits or at least what I need to ask for (all standard GTD I 'spose) and maybe enlighten me as to what the cause is?
by the way, I can see no other leaks of fluid from any other point on the car.
Oh by the way, the clutch has the larger diameter pipe fitted to it (1/4 inch I think)
Thanks

Simon

 

[Frank Catt]

Replace the master cylinder - use an early type LAND ROVER unit with a reducing adapter from the 1/4 inch outlet pipe, Frank

 

[David Morton]

Possibly a perished slave cylinder seal. Take the assembly off, release the circlip behind the rubber gaiter and withdraw the piston, renew the seal, clean the bore (some motor engineers have a small honing tool to remove the crap in the bore) completely drain and renew the fluid. Hydraulic oil is anhydrous so if its been sitting for so long it is probably finished/Time expired. More to the point, check your brake fluid as well. Ford agent have a heat check on the oil they can run for you but if it's the same vintage as the clutch oil then it goes without saying.
Dave M

 

[Mike Inglis]

You need a master cylinder repair kit. Remove the master cylinder, find the part no on the cylinder, and any girling stockist will be able to supply. Don't waste your money on a new cylinder.
Mike

 

[Frank Catt]

Fifteen quid for a new cylinder against howmuch for a repair kit ? Frank

 

[Chris E]

How did you get on with this Simon?
I have a problem that I have to push the clutch pedal almost to the end of its travel before the clutch releases.

Does anyone have any advice how to solve this problem? I have a new 0.625 girling master Cylinder and a standard Renault slave cylinder. Would a bigger master cylinder help? If so, how big? ( part number/ source would be helpful). The pedal is very light at the moment and looks like roughly a 6 : 1 ratio.

 

[Simon]

Chris,

I replaced the seals in the master cylinder (standard GTD, I have the part numbers for the seal kit if you want them) as the cylinder and bore were in perfect condition. I also rebuilt the slave cylinder (Kit from Chris Cole or Renault dealer, about £30) after bleeding the system with an eeze bleed to pump the fluid into the system, all was well. Doesn't sound like it's related to your problem though.

 

[Paul Thompson 'Hooligan']

Hi Chris -

What Clutch are you using? and are your lines hard or braided? -

We use a heavier AP clutch (2300LB?) and use a 1" Master - gives a heavy pedal but does mean the clutch does'nt drag at all. Useful as its a paddle type and will pick up if it drags too much.

I know that Frank Catt usually gets the AP setup working with a 7/8" (0.875) so it might be worth dropping him a line.
/ubbthreads/images/graemlins/smile.gif

 

[Chris E]

Paul
I'm afraid I don't know what the clutch is as since buying the car I've been concentrating on extending the footwell and moving the pedals forward, ( you now need binoculars to see them!) and major mods to the front suspension . Apart from work on the rear brakes, I haven't touched the rear end so haven't done anything with the engine, gearbox or clutch.

I have fitted a braided line to the clutch, so maybe a bigger m/c will help.

 

Chris,

I also had the problem of a long pedal throw on the clutch. I changed the slave cylinder from the standard Renault (1.125” bore) to a Girling one I bought from Merlin Motorsport (.875 bore). This increased the motion of the slave cylinder piston by a factor of 1.65 for the same pedal travel (being proportional to the square of the bore ratio), naturally it made the pedal heavier by the same factor.

CU Sunday

 

[Robert Logan]

Chris,

We itinally used a 3/4 inch master and found the same problem as well as a slowness to release when on the race track. We changed the hard lines up to 1/4 inch and the master up to 7/8 inch and all the problems have gone away.

Change the master up one size and that will cure it I would hope.

Hope to see you all again soon in the UK,

Best wishes,

Robert

 

[Chris E]

Thanks for the advice everyone. I checked the pedal and found that at rest, it was already tensioned so must have been putting pressure on the system even before pushing the pedal.
So, I've adjusted it to give some slack, and this seems to have cured the slip.

The test will be the 250 mile round trip to Stoneleigh on Sunday!