clutch pedal soft when engine is started

[checkrail]

More trouble now, pumping the pedal there was no pressure because the MC is leaking fluid down into the footwell.
Why has that suddenly happened, the new rebuild kit was fine earlier today.
I hope that I can just only remove the MC, I have a access hole in the peddle box top

Thanks for all your suggestions John

[checkrail]

The weeks go by and I still can only select the gears when the engine is not running.
Just to recap: new master and slave cylinders and speedbleeder, the pedal has acceptable pressure but if I pump away at least 20 odd times it will become firmer.. I've wedged it down overnight several times but no difference, the cylinders are the correct bore size
I fitted a new clutch plate but the rest of the mechanism is original, so it's back to the same old question ' why does starting the engine affect the hydrauilics'

I'm afraid now at my age depression is starting to set in regards John

[reds4se]

Is the action of the engine vacuum acting on the servo a possibility, Try bleeding the system from the servo outlet port or remove it and check it is not full of brake fluid.

[wdb]

The first thing that comes to my mind is that the transmission input shaft is not able to spin freely, specfically it is binding at the crankshaft end, which would prevent gear selection with the engine running regardless of whether the clutch was disengaged.

But the whole soft pedal thing is odd. Crankshaft thrust washers having excessive play? It's baffling.

[rgh0]

It is not the engine affecting the hydraulics it is the clutch not disengaging at any time. With the engine stopped you can select gears with the clutch not disengaging but with it running you cant that is normal. The question is why is the clutch not disengaging and from your descriptions it appears an issue with fully bleeding the system or adjusting the lever arm or some issue with the setup and reinstallaton of various clutch components when the work was done.

The starting point is how much iss the lever arm moving when the clutch pedal is depressed ?

regards
Rohan

PS Your steadfast refusal to obtain a camera and post photos makes all of this diagnosis much much harder with your various problems

[oldelanman]

John,
Are you sure you fitted the new clutch disc the right way round ? The hub is offset and they are usually marked with "FLYWHEEL SIDE" or "ENGINE SIDE" I don't think that is mentioned in the Workshop Manual.

[checkrail]

Thanks for all your replies, but please note that all I have done is change the clutch plate, the rest of the mechanism has not been interfered with. The clutch was working fine the only reason I changed the plate was because the rear core plug had to be changed which gave me the chance to check the plate.

John

[rgh0]

Please just answer the simple question I have asked - how much does the clutch lever at the slave cylinder pushrod move when you depress the clutch pedal

cheers
Rohan

[checkrail]

i've had computer problems all day Rowan, however, the measurement from the circlip to the clutch fork is 80mm with a couple of mm free play. This setting gives easy gear selection with the engine off and the pushrod.
fully home in the cylinder and the circlip in its correct slot

Thanks John

[smo17003]

For less than £10 you can buy from Ebay an Endoscope/Boroscope that plugs into your mobile phone. They're a bit of a pain to set up, but they are useful for seeing into hidden areas on the car. For your clutch problem you would pull back the gaiter and insert it into the bell housing. Wriggle it around a bit while someone depresses the pedal and you can see (and record) what's happening inside the bellhousing.

I've just used mine tonight to check the connections on the fuel sender (gauge not working) at the back of the fuel tank.

https://www.ebay.co.uk/itm/156019738002 ... 6596579227

[draenog]

i've had computer problems all day Rowan, however, the measurement from the circlip to the clutch fork is 80mm with a couple of mm free play. This setting gives easy gear selection with the engine off and the pushrod.
fully home in the cylinder and the circlip in its correct slot

Thanks John

Sorry to be blunt, but forget about when the engine is off! As Rowan says, when the engine is off you can change gear without the clutch, so it proves nothing.

[rgh0]

I presume the distance of 80mm is with the pedal not pushed. What is the distance when the pedal is pushed? it should increase by around 20 mm.

cheers
Rohan

[checkrail]

Yes those are the approx measurements

John

[h20hamelan]

Confused me, 20mm on slave?
As log as you’ve got 20mm, then there is something else. Someone mentioned clutch faces correct way.
How did you measure 20mm?

[checkrail]

I now have approx 100mm total when the pedal is held down, I'm working single handed so wedged the pedal down
John