Clutch dragging or not?

[Mac]

Currently testing things dry before actually starting and trying to drive it.
After bleeding the hydraulics, clutch seems to be working, pedal meets resistance and I can see it moving the clutch actuating arm but it doesn't seem to be disconnecting the clutch totally.

Maybe it's just because it's new I dunno, got someone to push the car and clutch would let go of flywheel so they could move the car when pedal was pressed but it was definately harder to push than if it had been in neutral and I could hear the clutch plate, sounded like it was dragging.

Does it just need to be used, or slave cylinder moved forwards, or am I worrying about nowt?

Car is a MKII Spit, friction plate is in right way round, clutch is bigger B&B diaphram (later car stylee) with relevant flywheel, actuating arm and slave, don't appear to be any hydraulic leaks. I rebuilt the master cylinder which seems to be working as it should, slave and pipe are new as is clutch, thrust bearing, etc.

[Clive]

Could just need using a bit, but make sure the arm starts moving and no free play.
May just be some crud/grease holding things up, but worth checking fully now. If the car starts I would try it and see, or just turn the engine over in gear on the starter with the clutch depressed. That may give a better idea.

Clive

[Mac]

Thanks Clive,
Willdo when electrics are done.
Maybe it's ok like that, I was just expecting it to let go more. Actuator arm is definately moving back and forth because I can see it moving through the bellhousing when pressing the pedal and you can feel the resistance of the diaphram on the pedal.

[AndyV]

A couple of points to look at:

Is the pivot pin (or a bolt) still in place with its brass bushes? Without them the arm will still move but will lose some throw.

Where the slave cylinder slots into the bell housing is the cinch bolt done up tight? Also you can gain a bit more "push" by making sure the slave cylinder is pushed well into the bellhousing before doing up the bolt as it can be slid in its housing forward and aft by 5mm.

Using it will help too.

Cheers
Andy

[Mac]

Thanks Andy

New bushes and pivot pin, the kind that don't drop out

Moved slave all the way forwards and it’s better, can push car back down drive with me foot hanging out of the door.

However the clutch only completely dissengages right at the bottom of its travel, and starts engaging again about 1-2cm off the floor which seems too low.

Any ideas or is it ok like that and will get better with use?

[rhodes]

I replaced a relatively new clutch in attempt to cure juddering.  This actually worked but I found that the pedal had to be pushed further down to disengage.  I presume this is due to a slightly thicker lining.  It is quite useable but has not got any better in 3000 miles.

[heraldcoupe]

The current B&B clutches are made by Delphi, they are not as tall as the original, ie the fingers of the cover are further away from the release arm. This means that there is some considerable free play between the clutch and it's release bearing. This in turn means that only half of the available piston travel is used in a useful range, the piston is up against it's retaining circlip pefore the clutch has fully disengaged.
These clutches have given me headaches in the past, easiest solution is to extend the pin which engages against the slave cylinder piston, which effetively movesthe operating range. A more elegant solution would be to have a taller release bearing carrier turned up. Neither approach would be necessary if Delphi sold a clutch which worked in it's intended application.
Cheers,
Bill.

[Mac]

Thanks Rhodes,
So is there any way I can adjust this without having the geabox off agin?
Only things I can think of involve having the box off, longer actuating pin.

Actually when I broke the engine down the pin had dropped out and the clutch was still working so it was set up better before then now with the conversion.

What about if I have the slave out and grind the cuttout for the clinch bolt back so the slave will go further into the bellhousing? Anyone know if it's solid alloy behind the clinch bolt cutout or will I break through to the hydraulic chamber?

I've also got the original slave cylinder for the old clutch, maybe that will be better or not compatible??

[Mac]

Thanks Bill, yeah I was thinking about that but would involve having the box off agin wouldn't it? Or can I get the actuating arm pin out with the slave and bracket off?

Can't use the old slave, different bore.

Any idea about grinding the cutout for the clinch pin on the slave back to move the slave forwards say 1 cm?

[heraldcoupe]

The bore is parallel, so you would have to be careless to break through the cylinder wall. I dislike this solution as it is clumsy, but I have resorted to it myself in the past. It's surprising how far you need to extend the groove to make this work,
Cheers,
Bill.

[Mac]

Ok, I'll see how it goes trying to get the actuating pin out through the bracket hole but I reckon it's going to be a burger. Had a go at me old one and pin is a press fit - drifts out.

If not I'll try grinding the groove in the slave further back.

[heraldcoupe]

If you're grinding ally with a power tool, be sure to use a new disc which has never cut steel or iron. Aluminium will quickly clog a disc on it's own and needs care at best, mixing with ferrous oxide will cause a thermite reaction. I would stick to using a file for my own safety,
Cheers,
Bill.

[Mac]

Thanks Bill, probably go with a hacksaw and file. Just wondering how much you can cut back that groove before the bracket starts to lose purchase on the slave

[Clive]

Thermite, fabulous stuff ;D

[heraldcoupe]

[quote by=cliftyhanger link=Blah.pl?b=spit,m=1177311721,s=13 date=1177440431]Thermite, fabulous stuff ;D[/quote]

Until it takes all the skin off your hands! :'(

[Mac]

Sorted
Cut clinch bolt cutaway back by about 1cm leaving same amount of lip as on other end.
Clutch now disengages halfway through pedal movement, with a couple of cms free play at rest.