Clutch problems

[JonathanT]

I recommend that you double check that any replacement slave cylinder has the same bore as your old one. I recently had mine replaced and the first one that was sent was fractionally smaller diameter (I think) which meant that the clutch pedal was almost impossible to move.

[Paulprior]

Hi Guys, being new to TVRs, who are the recomended usual sources of such things?
Thanks

Paul

[Paulprior]

Hi, so I have removed the slave cylinder as in the photos, is this standard? Main reason for asking is that it had 2 washers fitted between the flange and bell housing on each side.
As the brake pipe nut was 1/2 inch I assume the nut thread is also imperial, can I get a direct replacement or do I need to convert to metric?
Thanks
Paul

[QBee]

Usual sources are:

TVR Power
TVR Parts
Racetech TVR
ACT TVR

I added the TVR to the last two so that they google accurately.

There are one or two others

[Paulprior]

Just a quick question on the slave cylinder, when i removed the 2 mounting bolts there was what felt like a spring pressure pushing the cylinder back for about 5mm, also the 2 washers that were fitted inbetween the cylinder and housing, i have ordered a new one from TVR Powers but does anyone have any thoughts on what i have seen?
Thanks
Paul

[phazed]

A bit of pressure is normal but washers aren't!

[Paulprior]

Ok, I was just wondering if an incorrect cylinder had been fitted and the washers had been fitted to reduce pressure, and if there should be any pressure on the clutch at all until you activate the pedal
Paul

[Pupp]

Assuming it's not the wrong slave cylinder (and you'll be able to tell that by comparing with the new one but be aware the bore sizes are likely to be different as the currently supplied ones are slightly smaller diameter than those TVR fitted), then the piston is supposed to be pre-loaded against its internal return spring as the cylinder is clamped up. In it's resting position (ie foot off the clutch), the slave is compressed, and then extends to push the push-rod in operation.

Sounds to me like the washers might have been added in an attempt to either alter the clutch bite point or to allow for a non-standard height pressure plate to be fitted. Have a peek inside the bell housing at the pivot bolt and you might find that has some washers under it too.

Alternatively, if the push-rod is too long for some reason, the washers might be there to prevent the clutch itself being preloaded if the slave piston completely bottoms out in its bore when clamped up. Afraid there are quite a few potential variables, especially if someone has put a non-standard clutch in it but it's all pretty logical so should be easy enough to suss what's occurring.

[Paulprior]

So a preload sounds ok then, it's just a matter of how much, if I fit the cylinder with the piston fully back any idea on how close to the bell housing I should get before I get the feel of the preload?

[Sardonicus]

You should be able to push the slave flush to the bell housing with your palm if you cant you have issues

[Paulprior]

With or without resistance?

[Sardonicus]

Paulprior said:

With or without resistance?

Like Pupp says with resistance your purging the fluid back to the res and compressing the light spring

[Pupp]

Fit it before filling or even connecting the hydraulics; we're over-complicating things

[Paulprior]

Hi, sorry for a lot of basic questions, it's just that I want to ensure that when I refit I'm not applying to much pressure before I actually operate the clutch, I assume that can't be good, I should be able to compare the old and new tomorrow as well as refit, maybe then it will appear more logical
Thank
Paul

[Pupp]

The spring that is providing the resistance you're feeling when installing the slave is there to keep the piston in contact with the pushrod and take up clearance etc. If the concern is that the pressure you're feeling might partially operate the clutch, it's nothing like strong enough to do that... that could only happen if the piston bottoms out before the clamp faces mate.

When you compare new slave with old, you'll probably find the new spring is weaker than the old one.

[Paulprior]

Hi
I compared the new to old cylinder, but the old one didnt move as it should, in fact without trying extra force it didnt move at all, it was much clearer to see whats what with the new one, anyway, i rebuilt the new one without the washers for spacers and everything works great, thanks for all your help
Paul

[Pupp]

Good work, glad it's sorted. If you can coax the piston out of the old one, probably scope to rebuild with a new seal and spring as a spare after cleaning up... seal kits tend to be bore size dependent (think the oem TVR one is 1 inch)