sticky clutch

[pcoghlan]

Got the engine running this morning and was hoping to pull the car out into the sun and give it a much needed wash. Unfortunately after bolting the clutch slave cylinder back in place I seem to have a problem with the clutch.

Pushing down the clutch pedal results in it staying on the floor?! I need to hook my foot under the pedal and pull it up again.

There is pressure when it is being depressed and from what I can see it is indeed depressing the clutch (although not enough to engage the gearbox) but wont return to the non-depressed position.

I managed to push the actuating rod back into the slave cylinder so that isn't stuck. I am also able, with some effort, to depress the clutch fork so again that doesn't appear to be frozen.

So I am a little at a loss as where to go from here to get a working clutch. Should there be some spring to return it. I would have though the clutch fork would do that on its own.

Any input much appreciated. I would love to get this moving. The thing is now 5 years old and has 14.4 miles on it!

Thanks,
Paul

[JonnyT]

There is a spring in the master cylinder, but having said that it shouldn't really be required to return the pedal because as you say the cutch fork should do most of that.

Does the clutch fork return immediately after depression (without the asistance of the slave)?

[TINKA]

Not entirely sure what your problem is, but the heavy action you feel when pushing the clutch pedal down is because you are pressing in the spring loaded fingers or diafram ( depending which type of pressure plate you have ), and it is these that return everything to its original position when you release the pedal. If you are operating these as you say you are in your post it sounds like you have a problem with your pressure plate ( probably needs replacing) unless something is sticking but I would of thought this unlikely due to the strength of the springs.

You need to make sure what exactly is happening when you operate the clutch pedal. HTH

[wilf]

Two possibilities:

the clutch slave has travelled furrther than it should and either:

a: the piston has popped out of the end of the slave cylider bore and wedged itself at the extreme of travel

or

b: you have overstroked the clutch so far that you have damaged the diaphragm.

Hope it is a.

[Toddy]

Had this exact problem a couple of weeks back.
Mine was caused because the slave cylinder pushrod has sideways force on it due to the clutch actuating arm moving on an arc, not a lot but enough to cause it to jam on the pushrod retaining washer.
I sorted mine after phoning that wonderful Mr Brookes as follows :
remove the rubber dust cover from the end of the slave cylinder, remove circlip, remove washer and pushrod open up the hole in the washer and round off the edges of the hole, reassemble , problem gone

[pcoghlan]

Thanks guys, I will head out shortly and have another look. I have an access port in the transmission tunnel through which I can see/bleed the clutch.

I think the trick here is to disconnect the slave cylinder from the clutch forks and check that both move freely.

I will then liberally apply lubricant to the piston/rod and rod/clutch and reassemble to see if this does the trick.

Now for the possible bit error on my part!

there are two fittings on the actuating rod, a rounded element and a lock nut.

I think I have, wrongly, put them either side of the clutch fork. So, the rounded nut is the rear of the forks and the locknut is to the front of the forks. I now see, from the bottom photo in the URL below, that the locknut should be behind the rounded nut. I don't know if this would cause my problem (friction?) but I will switch it when reassembling it.

I would have thought there would be a need to have something in front of the forks to prevent the rod from slipping out?

Building an AC Cobra Replica: July 2007

Hope this all makes sense!
Paul

[DELAGE]

Having looked at the car re your pictures the engine really needs to come out. Headers need blasting and wrapping or ceramics, header tank does not look to cleaver, plumbers pipe work needs to get rid. and some steam cleaning work. Rocker cover's need a deep clean and polish.

As regards the clutch as said, the fingers or springs may be week which controls the pressure plate, also to consider the thrust bearing has a sleeve that fits on the out-put shaft that may have become rusted and holding things up, also due to ten years lay up the clutch master cylinder may be partially seized. If the clutch wont clear it indicates there is a problem.

Before taking it to an MOT or even considering driving it on the road all calipers should be checked and brake pads replaced as they are probaby rotten; good project however but make sure it's right

[pcoghlan]

Delage, I am not sure which of us started drinking early today but I am somewhat mystified by your reply! I can only assume you are referring to the picture I posted which is not my car but merely someone elses car and an example of the possibly correct slave cylinder installation.

Being in the US I doubt an MOT will neither be an issue or required!

Re the calipers/brake pads (I am not sure how they have come up in a clutch thread?!) but they are in perfect order and as new with only 14 miles on them.

The "laid up for ten years" remark has me thinking you might be replying to a different thread as my Cobra certainly hasn't been laid up for 10 years?

Confused,
Paul

[Toddy]

Paul, I would say you have sorted your problem
As you say it should be like the bottom photo, the rounded end just bears on the actuating arm, it is not bolted to it

[pcoghlan]

Toddy, if only it were that simple...

OK, it seems the rod that connects between the clutch pedal and the master cylinder behind the driver side wheel has snapped. I will call GD in the morning but I suspect this means a new master cylinder as opposed to a new rod.

Being in Florida if anyone knows of a generic replacement that saves me having to get this shipped from the UK it would be greatly appreciated.

I have reconfigured the rod to the clutch fork as per the photo in the previous post but am now against a brick wall waiting on this replacement.

Many thanks,
Paul