Clutch pedal on the floor

[69S4]

You're going to love rebuilding the slave cylinder (maybe you've done it before!) and you might consider a full replacement - not a lot more expensive than a rebuild kit.
Another option you might consider is to install a remote slave cylinder bleed nipple. Instead of installing the nipple on the slave, you can install a banjo union and run a s/s braided hydraulic line up to an accessible location in the engine bay and install the bleed nipple at the end of the line. Makes bleeding the slave cylinder almost civilised.

I've never bothered with rebuilding the slave cylinder, just replaced it with a new one - as you say it's not that much more expensive. I don't remember it being particularly difficult to bleed either once it's back in place. I last did it about a year ago when I boiled the clutch fluid after being stuck in a London traffic jam for two hours. Getting the car up on ramps so I could get under it was about the hardest bit although getting the top off of the master cylinder to add more fluid might run that close.

Your remote bleed nipple idea is definitely one to try in the future though. I wish I'd thought of it when I had to change the clutch slave cylinder on our Land Rover about 18 months ago. Two days before we were due to go to France I was lying in the snow under the car with the whole of my left arm soaked in brake fluid from trying to screw the bleed nipple back in.

[stuartgb100]

Well, well,

It was the slave cylinder. When the old rubber seal when removed, the sides were completely parallel with each other.
When you look at a new seal, the sides taper.

And yes, I'd forgotten how much fun a slave rebuild is !!
Mind you, when it's ?5.75p for the kit as opposed to ?55 + Vat for the slave cylinder (Past Parts)
you can put up with a fair bit of hassle !!

That remote bleed is a good idea (when I've more time), but I did manage to put some heat wrap
around the manifold and Y piece for added protection.

Thanks for the help.

Regards,
Stuart.

[RotoFlexible]

It was the slave cylinder. When the old rubber seal when removed, the sides were completely parallel with each other. When you look at a new seal, the sides taper.

I'm puzzled as to why you didn't detect any leaks or loss of fluid. If the pedal went to the floor because fluid was leaking past the slave seal, certainly you would see leaks at the slave (possibly contained by the dust boot) and fluid loss. If on the other hand, air was drawn into the system when you took your foot off the clutch - but both the clutch arm and the return spring are pushing the piston back up the slave cylinder bore, which you would think would prevent air from entering.
In any case, I will include a slave rebuild kit in my spares for my upcoming trip - or possibly, just preempt the problem by rebuilding it before I leave.

[stuartgb100]

Hi Andrew,

My dim and distant memories suggested that clutch fluid leaks were linked with slave cylinders,
so when I posted, I was not surprised to see people pointing me at the master cylinder.
Even though it's a simple system on the Elan, I thought best to ask first.

Can only say that I made it back home from London (approx 70 miles) with no loss of fluid, but
lots of pedal pumping before each gearchange.

Regards,
Stuart.

[billwill]

You problem sounds like air in the cylinders or the tubing.

It's been a while since I crawled under the car to view the clutch slave, but I seem to remember that it has two identical hydraulic holes. One for the feed from the master and one for the bleed.

You can fit the feed in the top OR the bottom hole. If you fit it in the top you can hope that the system will seld-bleed, but in practice it is probably better to fit the feed in the bottom hole and the bleed valve in the top hole and go through the normal hydraulic bleeding procedure.

[Robbie693]

You problem sounds like air in the cylinders or the tubing.

It's been a while since I crawled under the car to view the clutch slave, but I seem to remember that it has two identical hydraulic holes. One for the feed from the master and one for the bleed.

You can fit the feed in the top OR the bottom hole. If you fit it in the top you can hope that the system will seld-bleed, but in practice it is probably better to fit the feed in the bottom hole and the bleed valve in the top hole and go through the normal hydraulic bleeding procedure.

I've always been curious about this - my slave has inlet and outlet side by side, first I thought I should rotate the slave but then the boss for the spring would be in the wrong place. So, are there more than one design of slave cylinder?

Robbie (still with clutch probs)

[fatboyoz]

Stuart,
Probably not related, but found this whilst trolling for something else.

"Another clutch problem I experienced was the circlip which retains the slave
cylinder slipping out of its groove. The cylinder then moved axially until
the circlip locked against a flange. I was able to get home by pumping the
clutch as if I had spongy brakes."

Colin.

Hi Andrew,

My dim and distant memories suggested that clutch fluid leaks were linked with slave cylinders,
so when I posted, I was not surprised to see people pointing me at the master cylinder.
Even though it's a simple system on the Elan, I thought best to ask first.

Can only say that I made it back home from London (approx 70 miles) with no loss of fluid, but
lots of pedal pumping before each gearchange.

Regards,
Stuart.

[billwill]

You problem sounds like air in the cylinders or the tubing.

It's been a while since I crawled under the car to view the clutch slave, but I seem to remember that it has two identical hydraulic holes. One for the feed from the master and one for the bleed.

You can fit the feed in the top OR the bottom hole. If you fit it in the top you can hope that the system will seld-bleed, but in practice it is probably better to fit the feed in the bottom hole and the bleed valve in the top hole and go through the normal hydraulic bleeding procedure.

I've always been curious about this - my slave has inlet and outlet side by side, first I thought I should rotate the slave but then the boss for the spring would be in the wrong place. So, are there more than one design of slave cylinder?

Robbie (still with clutch probs)

Ah, no, they are basically side-by-side, but as I recall it can be twisted slightly to put one above the other partly. Especially during a bleeding operation.

[twincamman]

WELLLL you may think me a bodger ---but ---I never bleed a clutch slave cylinder --- really ---I JUST FILL THE MASTER AND PUMP UNTIL THERE IS PRESSURE AND LEAVE IT ----THE POSITION OF THE BLEED HOLE ALLOWS THE SLAVE TO BLEED ITS SELF -----REALLY ----saves a lot of grunt work ------ED

[GrUmPyBoDgEr]

You problem sounds like air in the cylinders or the tubing.

It's been a while since I crawled under the car to view the clutch slave, but I seem to remember that it has two identical hydraulic holes. One for the feed from the master and one for the bleed.

You can fit the feed in the top OR the bottom hole. If you fit it in the top you can hope that the system will seld-bleed, but in practice it is probably better to fit the feed in the bottom hole and the bleed valve in the top hole and go through the normal hydraulic bleeding procedure.

I've always been curious about this - my slave has inlet and outlet side by side, first I thought I should rotate the slave but then the boss for the spring would be in the wrong place. So, are there more than one design of slave cylinder?

Robbie (still with clutch probs)

Ah, no, they are basically side-by-side, but as I recall it can be twisted slightly to put one above the other partly. Especially during a bleeding operation.

This ones been covered a number of times previously & the overwhelming majority agree that the slave Cylinder must be rotated until the Bleed Nipple is uppermost otherwise Air can remain trapped.
To facilitate this the Spring can/must be unhooked & then hooked up after the bleeding has been done.
That's the way I've always done it & have never had any problems.

Good luck
John