50 replies to this topic

[unburntfuelinthemorning]

Can you post up a photo of the relationship of the Clutch Cover, Arm and Slave ?

 

 

Here we go:

 

And here's some with a worn but un-bent arm laid over the existing one:

 

 

Does everything look alright?

[Spider]

Sorry - I meant to reply here a day or so ago !!!

 

The Arm at rest does look like it's standing a bit more vertical than what I'd expect with all new parts. It can be from the flywheel sitting a little further on the crank taper, a worn or odd plate, too much machined off the horns on the backing plate, however, I'd say, it's just within limits in this regard.

 

It also looks like, when disengaged, that the Piston on the Slave must be getting quite close to the Circlip in it. It does also look short in travel here.

 

Perhaps a Washer, similar to that in Timmy's Post will help, but I'd say, it only wants something around 0.5 - 0.8 mm would well do it, but I'd suggest looking in to the short travel first.

 

One item I don't think yet that's been suggest to check, is that when your foot is off the pedal, that it's 'hanging' off the Master Cylinder and not contacting the body. Also, how high is the pedal off the floor ?
Is there more than one gasket under the Master ?
Are there any spacers fitted under the Master ?
Is the Master a Clutch one (0.75" Bore) and not a Brake one (0.70" Bore) ?  Hard to do with these Master, I know, but it has been done.
 

[unburntfuelinthemorning]

Thanks Chris.  I did have some material removed from the horns, I discussed it on here and it wasn't as much material as could have been removed so hopefully alright with that.  I used a little lapping paste on the flywheel taper but kept it to a minimum so I don't think the flywheel will have moved in much at all

 

The slave cylinder doesn't actually have a circlip!  Nor did the old one, both AP.  There is still a little potential travel remaining.

 

I'll get a master cylinder at some point and sort out any problems with the pedal to master cylinder connection.  Thanks for the other suggestions about the pedal, that's a few more things to consider.  When I acquired the vehicle I had to replace the pedal box as an early one was fitted with a twin circuit brake master cylinder which was interesting!  It improved the brakes no end! 

 

It's definitely a clutch master cylinder and not a brake one!

Edited by unburntfuelinthemorning, 22 January 2020 - 06:11 PM.

[Rorf]

I totally agree with Moke, the resting arm angle is too close to the vertical. You mention that you had the horns machined down - what was the final height of the horns above the pressure plate?

 

My wok pivot pin hole was also badly worn so had it bronze bushed. My clutch takes up at the pedal halfway position and has never been better. 

 

I must say I learn't a hell of a lot on my last rebuild as far as mini clutches are concerned - and you cannot find any of this info in the manuals, only from the experiences of people such as Moke (Chris) and Calver

[unburntfuelinthemorning]

I've learned a lot about Mini clutches too Rorf whilst doing this engine.  You can learn a great deal from the manuals but you can't beat learning from the experience of others.

 

I can't remember how much was taken off the horns now but I did discuss what I was planning in this thread.

[Spider]

If the Horns were machined so that the Diaphragm Spring is flat when all bolted up, then the Diaphragm Thrust Plate should end up in the right place. If however, too much has been taken off, and the spring has gone past flat and 'inverted' then the Thrust plate will sit low.

 

Another thought I had is if the Thrust Plate has been fitted the wrong way around ? I doubt this would be the issue as I'd expect the Arm to be much more vertical than it presently is, but mention it as just something else to look at.

 

 

Rorf, thanks for your kind words here. There's many on the forum I feel with extensive experience, who are happy to step up to the plate. I agree with Unburnt's words that manual can only take one so far and that's where platforms like our forum run rings I think around any manual that we not only get the stuff that is in the manuals but also all the traps than many of us have fallen in to, what we found and how they were resolved. I've certainly learned a lot from our forum.

[unburntfuelinthemorning]

To follow up from before, the pedal was correctly hanging from the master cylinder and not contacting the body. 

 

I've had the pedal box out again and welded up and redrilled the pivot hole (don't tell Tiger99) in the clutch pedal as there was excessive wear although there was still pedal travel in reserve.

 

I've fitted a new master cylinder and this seems to have increased travel measured at the slave cylinder from 7/16" to 9/16" so I'm over the magical Cooperman requirement of 1/2" minimum travel!  I haven't tried driving it yet as I'm still working on the brakes so we'll see what happens when I do. 

Edited by unburntfuelinthemorning, 22 January 2020 - 06:29 PM.

[AP2020]

Looking at the photo of the arm, that looks fubared !  the wear on the end and I suspect the wear in the plunger is what is causing your issue, change for new undamaged and you'll be fine :)

Attached Files

•  New Picture (6).bmp   715.47K   20 downloads

Edited by AP2020, 23 January 2020 - 09:15 AM.

[AP2020]

Nick, as a matter of course, I'm not sleeving these holes. If they are good, I leave them. If they are worn, I repair them rather than toss.

 

The other items I am find a few of that wears on these is the bore for the Plunger. Again, I bore these true on an over-size (after clocking up to the outer spigot) , sleeve with Aluminum, then bore back to size.

 

For this and the Clevis Pins, I smear some Molly Grease on them. Of late, I'm also shoving some sponge rubber in the Gap that's between the Arm and the Cover itself. This seems to be a bit of an 'Ashtray' picking up all manner of grime that only causes them to wear. I can't yet say how effective this is.

 

You sleeve the plunger hole ?  as can be seen from the attached screen shot there isn't a lot of material left to hold a sleeve, how successful is your modification ?

Attached Files

•  New Picture (7).bmp   447.53K   13 downloads

[unburntfuelinthemorning]

Looking at the photo of the arm, that looks fubared !  the wear on the end and I suspect the wear in the plunger is what is causing your issue, change for new undamaged and you'll be fine :)

I refer the right honourable gentleman to the text in post numbers 1, 5, 9 and 30 of this thread.

[unburntfuelinthemorning]

Drove it today and the clutch is the best it's ever been!  Bites in the middle with plenty in reserve.  Thanks to everyone for the help.

[Rorf]

Pleased that you have eventually sorted your clutch out, well done.

[Spider]

Ace - thanks for letting us all know

[unburntfuelinthemorning]

So basically once every single clutch component had been repaired (the pedal) or replaced, it then worked properly!

[sonscar]

Years ago(40/) I took my wifes Mini to a "specialist" who told me they were all like that.A leyland dealer I took it to said also that thet were all like that also;because thet were almost all worn out.I replaced all the parts you did and it too was fixed.Steve..