Clutch question

[robb4100]

Hi everyone,

This must be the year to keep my car off the road. I am unable to shift into any gear. I presume that I am unable to get the clutch to engage.

I checked the clutch adjustment and the adjusting nut is all they way to the end -toward the far end from from the cylander.

I have noticed for a while that I need to press the pedal to the floor to get the clutch to engage and since there is no more room to push the adjusting nut out does this mean that the clutch needs repair?

Robb

[Frank Howard]

Robb,

You are probably due for a clutch master cylinder rebuild and/or clutch slave cylinder rebuild. As the exhaust is "wrapped" around the slave, chances are that it is shot. Don't forget to use the proper brake fluid, like Castrol LMA. Good luck.

[msd1107]

If it is a slave cylinder, the clutch pedal will seem soft.

Try pumping the clutch pedal. You may be lucky and get enough pressure to disengage the clutch and get into gear. Be ready to get the car to where it is going to be fixed. Shift without the clutch. Hope for no stoppages.

If you can't get in gear using the above technique, there are two other techniques.

One. Point the car in the direction you want to go. Put the car in gear. Start it on the starter motor (you can even do this with a passenger). Proceed as above.

Two. If you don't want to start on the starter motor, try this. Put the transmission in neutral. Start the car. Get out and push. When the car is rolling as fast as you can push it, jump in and push it into 1st gear. Proceed as above. You can have a buddy help push, but he needs to follow you incase you get stopped in trafic so you repeat the starting drill.

My dealer was 30+ miles away, and I did this twice on my old Stromberg car.

David

[1964 S1]

How's your clutch fluid level?
I suggest having someone get in the non-running car and pump the clutch pedal while you peek under the car to "measure" the slave cylinder piston travel and report back to us expurts
(if your fluid level is low, have them pump and measure, then top up the fluid and check for piston travel improvement)

[robb4100]

Hi again,

This took forever to get to but....

Replaced the seals in the master and slave cylander. replaced the hydrolic fluid. Still no clutch

I measured the travel on the push rod and it was only 1/4 inch or 6 mm. Is that right?

I also noticed that some of the fluid bypassed the piston in the slave cylinder. That does not seem right to me. It may have happened only in the first couple of pushes as the piston seated itself as I was unable to see any more come out as the clutch pedal was depressed.

Any more suggestions?

Robb

[john.p.clegg]

Robb

According to my notes,the pushrod on your master cylinder should move 3cm (full pedal movement) which will produce 1.5cm of movement on your slave pushrod.......
Do you have a removeable cover on your pedalbox? (makes checking this easier)

John.

[ttaunton]

Hi Robb
Sounds to me like your clutch plate is stuck to your flywheel. This used to happen to me a lot when I left my Elan over the British winter in a damp garage.
Happened on a big Healey as well.
It doesn't matter how good your hydraulics are, or if your release bearing is moving OK but if your plate is stuck to the flywheel then it's goodnight Irene until you can get it to release.
There are two methods that I have used with success, they will work as long as your release bearing is doing its stuff.

Number 1. First things first: Sit in the car, preferably not facing the garage wall. One foot on the brake and the other on the clutch. Lever in top gear. Key the starter. If you are lucky the clutch may release. If not then we need to use more power. (Starter motors are about 6-10 hp) Get yourself a helper, get in the car, bearing in mind that you won't be able to stop easily without stalling the engine, so early Sunday morning is favourite. Put lever into first gear, then turn the key, engine will start and you are on the move. You will be able to change gear without the clutch, the synchro will do the work: just "offer up" the lever to the next gear with a bit of pressure and the dogs will engage when the revs are right. It is easy to get the hang of. Coming down you need to be a bit more skilful, revving it while you are in neutral to match the revs before offering the lever up.
While going along use both feet to keep the clutch depressed and accelerate at the same time. The clutch may release immediately because you are now trying to put quite a few horsepower through your "stuck" clutch: you have the clutch pedal depressed so there is no spring pressure from the clutch cover, you are basically trying to put power through a layer of gunge. It will suddenly release, and you revs will rise, so be ready. I once had to accelerate hard past 70 to release mine. Once it has released slip the clutch to burn off the crud.
Number 2. This one is difficult and involves getting under the car. Remove starter motor so you can (with difficulty) access the flywheel, and feel the clutch cover inside the bell housing through the hole. Get someone to press the clutch pedal. The clutch cover is bolted to the flywheel, but between the bolts the cover is scalloped up, so rotate the flywheel into position and using a torch/morror you can just see the edge of the clutch plate inside, under one of the scalloped bits. Get a hack saw blade, heat it and bend it so you have a 4" bit at right angles. then grind the end into a knife edge. Working by feel through the starter hole, poke this under one of the scalloped bits of the cover, and you can then feel the edge of the clutch plate. Make sure she is still pressing the clutch. Push it between the plate and the flywheel or pressure plate, turn the blade, and you will hear a blessed "click" as the plate releases. Bob's your nob. When I finally replaced my clutch plate, I found that the flywheel, pressure plate etc were all coated in a sticky deposit, probably 20 years of condensation and clutch dust and a cheap plate.

[robb4100]

I am away from the car untlil later so will measure the master cylinder travel this evening.

Couple of questions.

1) the cluth pedal is very soft- could there be an air bubble?
will the ratio of master travel to slave travel tell me that?
If there is a bubble is the only way to clear it to do a bench bleed?

2) the lever into the clutch housing (the one that the slave push rod pushes against) has very little movement and feels like a hard stop at both ends. If the clutch plate were not stuck should I be able to feel some play as I push against the lever?

Assuming that this is a stuck plate and that it is caused by "crud" will it continue to be a problem without tearing it apart and replacing? I would rather fix it right than find myself constantly unsticking the plate.

3) Lastly should I be concerned about the little bit of fluid that bypassed the slave piston?

I know lots of questions

As always you folks are great,

Robb

[gjz30075]

Based on #1 and especially #3, your slave cylinder is shot. There should be NO fluid leaving the system.

Greg Z
'72 Sprint

[oldokie]

Fluid coming out of the slave cylinder is a BAD thing, did you hone the bores when you replaced the seals? Are you sure the seals are facing the right direction? Did you bleed the system?

[robb4100]

I left the bores the way that they were and replace the seal in the slave the same as it was before- just the one seal on the piston plus the dust cover for the slave. The master had two seals.

After I saw the leakage from the dust cover on the slave I pulled the dust cover back and had the pedal pumped several times with no more leakage. I will double check this again. I wonder if something was between the seal and bore and came free under pressure.

At any rate it seems like the best course of action with the slave is to pull it again (oh what fun!) and check the seal. While it is out I will do a bench bleed.

For clarification in case the original seal was backward the seal has two ends (one end is "open/flared" and the other is flush. Which end abuts the piston? It was not clear to me from the picture in the manual.

Robb

[robb4100]

For those postulating that the clutch plate is stuck should I be able to push on the fork arm and get any play. As I said in an earlier message I have very little motion in that arm and it feels as if I am hitting a hard stop in both directions. I would have thought that if I were to emulate the slave pushing against the fork arm I should feel resistance but a little bit of give.

Am I making any sense?


Thanks

Robb

[john.p.clegg]

Robb
There should be some play when at rest,but you will not get any movement when engaged trying to operate the clutch unless you've downed many cans of spinach,the clutch pressure plate springs are too strong for your fingers,if you can rig up some sort of lever you might be able to move the arm against the spring pressure...

John

[gjz30075]

Be sure to hone the slave cylinder before replacing the innards. This provides a surface that the new seal can mate to, much like primering a wall before painting.

[robb4100]

I'll get back to you after the weekend. the day job will keep me from getting under the car until the weekend.

robb