clutch pedal soft when engine is started

[checkrail]

Hi all, I've fitted a new clutch plate and slave cylinder with a Speed bleeder on my +2 and can select all gears (4 speed) when in neutral with the engine off. When the engine is started the clutch pedal goes soft as if it needs bleeding and its impossible to get any gears
This has baffled me, I've been trying the push rod adjustment but no luck
Has anybody else had this problem? Thank you in advance John

[alan.barker]

Air in clutch slave cylinder needs bleeding.
Alan

[checkrail]

Hi Alan, I've had the pedal wedged down overnight and it's nice and firm, bled it a couple of times with a clear tube on the speed bleeder, no bubbles there. started the engine but still unable to select a gear.
John

[smo17003]

Hi John, with the engine off, and a firm pedal, have you actually observed that the adjustment rod/release arm are moving back and forth when you press the pedal?

Mike

[checkrail]

Yes Mike that's working as it should, but the cylinder has free horizontal play in the bell housing although the circlip is in place.
John

[rgh0]

You need to push the slave cyinder fully forward so it is hard against the retaining circlip when adjusting the lever arm free play to the Lotus recommended 2 mm value. If the arm is moving around 10 to 15 mm but the clutch still not disengaging then something internally is wrong with the clutch or throw out bearing assembly

cheers
Rohan

[checkrail]

thanks for the replies.
The pedals gone spongey and now have bubbles in the master cylinder fluid, I have a repair kit so another nasty job with the pedal box.

John

[2cams70]

The clutch changes in feel depending on whether the engine is running or not? Are you sure? Never heard of that before and can't think of a scenario of how it could happen.

[checkrail]

No, the problem is I can select any gear but not when the engine is running, I have another job now changing the seals on the clutch master cylinder,

John

[rgh0]

No, the problem is I can select any gear but not when the engine is running, I have another job now changing the seals on the clutch master cylinder,

John

That simply says the clutch is not disengaging

[tonyabacus]

Set the clutch arm to the factory setting. With the engine off get someone to pump the pedal whilst you observe what is going on at the slave cylinder. Then check the same with the engine running, use a ruler or measure of some kind to make sure the push rod is travelling the same amount in both cases. Next observe what is happening in the master cylinder, does the fluid level change in both scenarios, and are there any bubbles being produced in the fluid in either situation.

If all these check out then it looks like an internal problem with the arm or the throw out bearing. Did you just fit a new clutch disc or did you change the the whole assembly, pressure plate, disc and throw out bearing?
Tony

[checkrail]

Hi Tony, I just replaced the clutch disc, the slave is new and overhauled the MC, but I think the clutch pedal pressure is not very heavy. I've bled the slave with the speed bleeder several times with no sign of any bubbles, but
I still think there should'nt be any free play on the slave, surely this must affect the clutch adjustment, perhaps I could add an extra circlip?

Thanks John

[rgh0]

There is always some free play in the slave mounting in the bell housingof a few mm, some slave cylinders have two grooves so use the grove closest to the bell housing just make sure the slave is pushed full forward when adjusting the lever clearance.

The clutch system is difficult to bleed due to orientation of the bleeder and can need multiple attemps. and is a two person operation unless you fit a speed bleeder to the slave as others have said after getting most of the air out wedging the pedal down with a piece of 2x4 against the seat and leaving it. However you need to be able to get some pressure in the system for this to work.

cheers
Rohan

[2cams70]

Is the clutch lever pivot pin correctly installed?

[snowyelan]

Is the new slave the same bore size?