clutch slave/master cylinders

[spiro]

just bleed the clutch system and found that I am not getting full travel on the clutch fork lever arm. The piston on the slave clynder is set right back and I have extened the rod but still no joy, it feels as the master cylinder can`t supply enough fluid to the slave. All the parts are new, car is at the end of its major restoration. (had clutch problem before the car was stripped) I have seen other TR`s with the slave cylinder spaced outwards. Is this a common fault also is there anyother type of cylinders I could try. Any ideas anyone

[Richard Crawley]

spiro,

clutch problems are, unfortunately, a common problem & it comes up on the forum every couple of months or so: So, first look back & read the 6 forum previous posts for guidance on what causes it & what to do about it. Try not to extend, shim or re-drill things in an effort to cure the problem as it really is not the answer.

[Guest harry dent]

Spiro,

As Richard said check former post,s.Have you looked at the clutch pedal arm to master cylinder push rod for wear in this area.

A simple fix is to drill out to 3/8" and fit the same size clevis pin.If you do not have 5/8" movement on the slave cylinder

push rod suspect a broken pin on the cross shaft.Have you checked that your thrust washers are the correct clearance

6-8 thou on the crankshaft.Is the slave cylinder bleed nipple on the top side as you will not bleed it upside down due to trapped air.Faulty master cylinder and or pipe leading to slave cylinder.

Clutch cover the wrong type?

Regards Harry.

[tim_trinda]

spiro

 

Have a look at the Buckeye Triumphs web-site, there is a whole section on clutches.

 

Good luck

Tim

[Peter Douglas Winn]

I went down this road some years ago with the same symtoms. After a garage (a relative's, which was very embarassing) did a rebore, the clutch did not work properly. To my expense we found out that the thrust washers for the crank had dropped out and every time the clutch pedal was used, the crank bored itself a bit more into the block. Result a new engine. So just in case please check your crank endfloat.

[Tom Fremont]

At the risk of preaching to the converted, it were well to absolutely minimize the time the clutch pedal is depressed on these cars. That means putting it in neutral each time we stop ( rather than holding the pedal down until the light turns green ), etc. Practicing this religiously for the last 30 years on TRs I've never had a problem with thrust washers, putting well in excess of 100,000 miles on them and still no excess end float. The method can even extend to shifting into neutral without de-clutching whilst the drive is momentarily unloaded.... ???

[Guest ron]

Spiro

If you have a 0.7" master cylinder it would be worth your while changing to a 0.75" master cyl from an early car as this gives a better clutch action albeit at the expense of a slightly heavier pedal.

Ron

[spiro]

thanks for replies, did have some luck by re-bleeding the system again with fresh fluid instead of what I had on the shelf. Got a better pedal but it could still do with a bit more. As I said before all parts are new including engine rebuild. I might try what Ron said and try a 0.75 master cylinder (did have a poor pedal before car restoration.) :rock:

[Tom Fremont]

Spiro

If you have a 0.7" master cylinder it would be worth your while changing to a 0.75" master cyl from an early car as this gives a better clutch action albeit at the expense of a slightly heavier pedal.

Ron

This is probably why, having just switched out an entire engine/gearbox assembly with clutch slave cylinder attached, marrying to an early type master cylinder, the pedal releases the clutch near the top of the stroke instead of mid-way.  ( First time in my experience having the release point so high. )

 

Not likely due to differences in linkage slop, so by deduction it would have to be the master cylinder!

[spiro]

It does feel that the master cylinder has bottomed out and that the slave cylinder could do with more fluid delivered to it. Thats why I asked if there was an alternative master cylinder available. I assume that a 0.75 master cylinder will do this, yes?

[Tom Fremont]

Doing the math yields 14.7% volume increase, therefore the same increase in stroke for the slave cylinder.

 

Can anyone confirm whether the larger master cylinder is still available?

[Andy Moltu]

If the clutch is still not fully disengaging with a 0.70 master it suggest there is a problem & swapping to a 0.75 might make an improvement but won't solve the problem - unless the master cylinder itself was the fault!

(The clutch should fully disengage with the 0.7 mastercylinder)

[Richard Crawley]

The clutch should fully disengage with the 0.7 mastercylinder

I agree with Andy. Fitting the earlier 0.75 cylinder is only masking the problem really.

[Guest ron]

My clutch did fully disengage with the .7" cylinder it was just too near the floor for my liking, so I tried a .75" cylinder and the release point is now further up and to my liking. Remember the car was originally designed with a .75" master cyl, they only changed it to to .7" to suit customers with weak left legs!!

Tom,The larger master cylinder was still available last year, I think I got it from Moss UK.

Ron

[spiro]

Its at the very bottom end of the pedal as Ron said and that`s before I have the carpet and felt  fitted hence my concern:rock:

[Richard Crawley]

Its at the very bottom end of the pedal as Ron said and that`s before I have the carpet and felt  fitted hence my concern:rock:

Mine is running the 0.7 cylinder & clutch action is perfect; firm but not excessive & dis/engages around half way up travel. But I have made certain that it’s all  set up properly (the dreaded taper pin) & absolutely nothing is worn, including the cross shaft bearings which, maybe, some neglect to check/change!

[JohnC]

Richard,

 

Likewise! I even went as far as fitting two bushes at each end of the cross shaft in the hope that I'll never have to remove it again

 

My one remaining potential trouble spot is the pedal box. Everything's fine so far, but I expect that's where play will appear next.

 

John

[Richard Crawley]

My one remaining potential trouble spot is the pedal box. Everything's fine so far, but I expect that's where play will appear next.

I seem to remember there are actually bronze bushes fitted into the pedals where they go onto the cross shaft so these are usually pretty bullet proof, especially if they have been lubricated on the odd occasion. I did however, have to fill weld & re-drill the clevis pin holes & fit new clevis pins.

[Kneeslider]

Just a thought, but have you put the slave cylinder on the bracket in the right place?  The pipe from the cylinder should be threaded through the bracket, then the cylinder bolted up.  I thought that was the problem with my setup first!