Hydraulic Clutch kit problems

[rogerb]

Hi
I know this has been raised a few times in the past, but after searching through, the only relative posting was back in 2005 and recieved no response!

My set up is: 1275 Midget engine and 4 speed box
I have been having trouble with excessive wear of the Carbon clutch release bearing, so have opted for the Hydraulic Clutch kit (from Birmingham Morris Minor Centre), and a ball bearing type release bearing.
All fitted OK. I have retained the original fork (i.e the Minor fork with the hole).

I am having terrible trouble bleeding the system and getting enough adjustment for the clutch to release and engage any gear.

After many a bad night where the air turns blue I am finanlly stumped.

Has anyone out there experienced simmilar problems and if so how do I get over them.
How far does the slave piston need to travel to release the clutch?
How long does the slave piston rod have to be (I cut mine to the recommended length, but wander if it is to short?

If I finally throw in the towel is it possible to revert to the mechanical linkage with the ball bearing type release bearing?

Any help will be very greatfully recieved.

Roger

[alex_holden]

The carbon bearing is usually pretty reliable. How many miles did you get out of them? Are you using a clutch with stronger springs than standard or something?

The ball-race bearing won't work with the mechanical linkage because it travels through an arc so it isn't guaranteed to always be concentric with the clutch.

[mrbenn]

Don't know if this helps, but I find I have to take off the spring on the clutch cylinder when bleeding it, just to allow the plunger to move a bit further.

[rogerb]

Hi Alex
I have not measured it but less than 1000 miles! The amount of carbon protuding from the metal carrier is aprox 1/8 inch on a new one (From MG centre Birmingham). I think I must have hit upon a bad batch as this was the second bearing to do the same thing, using the manual linkage. There was virtually no free play, (ie it was either in our out!) in the pedal to get it to work Regds Roger

[Kevin]

There was virtually no free play, (ie it was either in our out!) in the pedal to get it to work Regds Roger

Hi Roger I assume you are running 1275cc MG Midget Engine & Box complete with the original Midget Flywheel which in turn means you are running the Midget 6 1/4" clutch and on the few cars I have driven with this set up over the years the clutch action was on or off and quite awkward to drive.
If this is the case I suggest that you convert a Minor flywheel to fit the engine (or get one from one of the spares people) and then you can fit the Minor 7 1/2" clutch which gives an action like the normal Minor.
I dont have my manuals to hand to confirm the clutch sizes but the difference is around what I have quoted, and yes I run a 1275 Midget engine with a Minor flywheel and its fine.

[Packedup]

The ball-race bearing won't work with the mechanical linkage because it travels through an arc so it isn't guaranteed to always be concentric with the clutch.

I'm not at all convinced about this. Aside from concentric slaves (found on modern stuff like Fords) there's a lot of fork/ lever operated clutches around - In fact that's all I've ever seen! And aside from the BMC set up all the ones I've seen use a roller bearing - Which must be traveling through an arc.

If this is the case I suggest that you convert a Minor flywheel to fit the engine (or get one from one of the spares people) and then you can fit the Minor 7 1/2" clutch which gives an action like the normal Minor.

If that is the case and a Minor flywheel is adapted, I could be interested in the old 1275 Midget one at the right price. My Minor has a 1275 Midget engine and I have a 1098 Midget...

[Kevin]

Hi is it a standard 1275cc Midget flywheel you are after ? as I may know of one, send me a PM if so and I will find out.

[GAS]

I've a hydraulic clutch on my traveller and found that the easest way to blead the system was to back blead it.
This means that you fill the master cylinder through the blead nipple.
An old washing up bottle and some tubing does(remember to secure the tube to the bottle with a tie wrap or something as you will be squeesing the bottle hard)
This has worked for me fist time,everytime.

Good Luck

[superchargedfool]

my personal feeling is that if you are going hydraulic then a modern concentric made to fit is a good option.

I have just fitted a concentric to my 5 speed minor and it is lovely to say the least.

fork operated bearings self centralise on the clutch when pressure is applied, as long as the way they are mounted leaves a little bit of float.

[bmcecosse]

Can't see that the method of moving the lever has anything to do with the roller bearing operation - either mech will move it in an 'arc' if it's mounted on the wishbone lever. But that 'arc' will be very small. If the carbon thrust was rubbing on the clutch all the time - then yes it would wear away in no time. But the hydraulic method works fine on the Midget (although it IS in/out!) and so it will work for you. Try lengtheneing the push rod.

[rogerb]

Well folks, thank you for all your suggestions and ideas. They all gave me something to think about.

The problem is now solved and the car going again under its own power.

Who had the correct solution? Well after the bleeding was eventually done, it was bmcecosse! Simple really just lenghten the push rod!

I had quite niavely followed the supplied instructions and cut the push rod to just over 4 inches, this did not give enough adjustment. I made another at 5.5 inches and lo and behold I actuially managed to over adjust it so the clutch was slipping. Simple adjustment back and away we went. It is now working very smoothly and feels quite natural, even the wife is happy, so that is a BIG plus!

Thanks again everybody, I knew that this forum would come up trumps again.