Experience with pull type clutch slave cylinders

[Kitchski]

Hi all,

Has anyone tried retrofitting a 'pull' type slave cylinder before (in installations where space doesn't allow a standard push type), and what kind of success did you have (or not have)?

Thanks

[Kitchski]

Hillman Imp. Using an Imp transaxle, but a different engine. Normally the Imp engine lays on its side, and the clutch slave cylinder (conventional type) is bolted on top of it, and operates the clutch by pushing against the release arm, the head of which sticks out from the top of the box.
Because I have a different engine bolted to the transaxle, I can't fit the standard slave cylinder as there is an engine in the way. I was told that pull-type slave cylinders are a thing, so was wondering if anyone had experience as I was thinking of fitting a pull cylinder to the reverse side of the release arm.

I currently have a concentric cylinder fitted, but it's ste and I'm planning to ditch it.

[Kitchski]

stevieturbo said:

Not something I've ever seen or heard of.

All slave cylinders push....I imagine designing a hydraulic system that pulls would be unusual, at least certainly within a car environment.

A quick bit of hunting around found this:

http://www.rallydesign.co.uk/product_info.php?prod...

Was just wondering if anyone had experience of fitting or operating one.

Little Pete said:

In my experience external slave cylinders on pull type clutches still push, they are just turned around so that they push the bearing away from the cover, not towards it.

Haven't seen one in front of me, but the link above seems to suggest otherwise, though I agree it's a bit oddball.

Little Pete said:

If you are stuck for space at the release arm could you not convert to a cable?

Possibly, yes. Converting to cable would be better at the clutch end, but more hard work at the pedal end. Definitely a valid option though.

Little Pete said:

I would have thought a concentric pull type slave would be ideal. What don't you like about the system you have?

So did I originally, but it's cack! The gearbox isn't ideally suited to housing it anyway, and if you get any leaks (which I do.....a lot) then it's engine out again to try and rectify it. It works well in operation, but seems to keep failing around the seals (on the unions and on the cylinder bore itself), and it's not like it's being asked to shift too much weight, or even overthrowing etc.

I might give it one more chance yet, as it's the quickest way of sorting the problem, it's just that if it fails again it becomes a royal PITA.......again.

I like the idea of having the hydraulics easily accessible. I've sourced the correct release arm so just need to find a way of operating it.

[Kitchski]

GreenV8S said:

Sounds like this installation has already had a lot of work put into it.

Just a bit!

GreenV8S said:

Would you consider mounting the 'push' slave t'other way round and fabricating a pull rod attached to the far end? I'm envisaging chopping off the end of a clutch release arm where the slave pushrod normally seats, attaching a pair of straps that run down either side of the slave and a cross bar at the far end that hooks over the clutch release arm.

Not quite sure I follow you there, but I've possibly had a similar idea already where I mount the convention slave to one side of the head of the release arm (which points upwards vertically) and then fashion a crossbar horizontally across the top of it. Then I'd have the slave on one side, and the other end either anchored in a rose-joint, along with a rosejoint on the top of the release arm for the crossbar to pass through.

[Kitchski]

Little Pete said:

I've not seen that rally design thingy before but that could be your answer if you have enough room. Looking at how it operates I imagine it is quite a bit longer than a conventional slave.
You will probably have to experiment with release arm travel/pedal travel ratios but it sounds like you'll be up for that given what you've already achieved!
What type of vehicle is this in?
Sorry just re read your previous post

Edited by Little Pete on Thursday 10th November 20:10

I think I'll have enough room there, but would need to measure up first. I should imagine it'll be a case of limiting the pedal travel, which I've already made an adjuster for to prevent over-throwing the existing slave.

And yes, Hillman Imp running a Saxo TU5 engine.

[Kitchski]

227bhp said:

I'd be finding out why it leaks so often and going from there.
They're in daily use in millions of cars so you need to address that.

I think it's just a poor quality product. The unions don't seal properly and they're standard Goodridge hoses. The seals inside have been replaced already and keep leaking. And even if I managed to prevent it leaking, I don't like not being able to see what's going on in an area where I'm constantly having design issues. It could be the way that everything is set up is stressing it out somewhere. All looks true and can't see any issues, but doesn't mean there aren't any. I just think I'm done with this particular design.

Appreciate millions of cars use concentric slaves as a design, but they're not all the same slave. That's like saying there's no reason why your gearbox should fail, as millions of cars use them.

[Kitchski]

GreenV8S said:

I'm not sure I can explain it any better without a picture, but I'll try. Position a conventional 'push' type slave cylinder where you would have put your 'pull' style one i.e. so that it is in the right place but pushing where you want it to pull. Swap it end for end so that now it is pushing the right direction, but the body of the slave cylinder is in the way and prevents you connecting the pushrod directly to the clutch release arm. Now put a rectangular frame around the slave with the slave's pushrod pushing on one end, two sides carrying the force round the outside of the slave, and the far end connecting that force to the clutch release arm. The cage would be easy to make and has no moving parts - you just need to arrange a pivot for the slave cylinder pushrod to connect to it at one end, and the end of the clutch release arm to connect at the other end. I'd imagine it being welded up from a few pieces of bar and a salvaged pivot from a clutch release arm.

Ahh, I'm with you now. Yes that's a good shout - a more effective version of what I was thinking of, cheers

[Kitchski]

Saxo 1.4 flywheel & clutch cover, Sierra 1.6 Pinto plate. Bearing is part of the concentric setup, but would be transferring it to a boss I'll get turned up that can be operated by the release arm. I can't use the standard setup as there is a 20mm adapter plate between engine (Saxo VTR 1600) and the Imp transaxle, so I need to make up the difference by fitting the release bearing to a boss that is operated by the release arm, rather than directly off the arm itself.

[Kitchski]

This is my reader's car thread if anyone's intrigued:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...