Clutch lever/actuation problems

[Bendy toy]

The clutch lever has recently had too much slack and only just clearing the clutch plates with lever pulled right in. Its hydraulic of course but it felt like the cable needed adjusting.

I bled he hydraulics but there was no change. Ive fitted a new slave cylinder but that looks like a waste of money because its still the same. It was a pig to bleed and Ive even had the lever tied back overnight to clear any bubbles. (it works with non ABS non servo brakes). But the action is just the same.

There is no sign of clutch slip so no reason to think the clutch plate has failed. Ive whacked it open on steep hills in high gear bit no sign of clutch slip. But especially when cold its only just clearing when lever pulled in.

So could it be the master cylinder needs new seals (slave is new) or have I worn out the clutch so the hydraulics cant now open it properly?

PS Ive ruled out the clutch pushrod as a source of the tickover rattle in neutral. Withe the slave cylinder and pushrod removed it still rattles.

 

[Delboy777]

Pressure plate ?

 

[Bendy toy]

What are the pressure plate symptoms on a hexhead?
I've had a pressure plate fail on a car. It had a knotchy springy action and short travel. Apart from the slack, this feels normal. There is mo release bearing noise


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[Mistacat]

Was it topped up with the same colour clutch fluid, I understand that the different colored fluids are not compatible. (seen a clutch topped up with brake fluid not good)
Is there enough free play between the clutch lever and the piston.
Is the master cylinder piston returning fully.
These would give the symptoms described.

 

[Bendy toy]

Thanks for the advice I'll strip the master cylinder and see if it helps. Maybe new seals are available.

I used BMW clutch fluid from Motorworks. I was suspecting the master cylinder but having already changed the slave with no benefit wanted to be sure.

I'm fairly sure the clutch itself is ok, because it works normally apart from not being opened properly by the hydraulics.

 

[MikeO]

(seen a clutch topped up with brake fluid not good)

Eh?

 

[Bendy toy]

Clutch uses a light oil similar to Citroen LHM. It won't absorb water like brake fluid.


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[MikeO]

Clutch uses a light oil similar to Citroen LHM. It won't absorb water like brake fluid.

Well, you live and learn...

Is that for all clutches from the original 1200 forward?

 

[Bendy toy]

They've probably always had mineral in the clutch. I'm calling into Benhams later today so will find out.


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[MikeO]

They've probably always had mineral in the clutch. I'm calling into Benhams later today so will find out.


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The 1150 is DOT 4, common to the clutch and brakes - I wonder why they changed it?

 

[Beemerman59]

I seem to recall the stipulated fluid for the clutch on 1200's was called Vitamol.

Interesting info here:

http://www.largiader.com/articles/mineral/

 

[AberdeenAngus]

Well, you live and learn...

Is that for all clutches from the original 1200 forward?

I think it's mineral oil for all the 12's. There's a warning on the reservoir lid about not using brake fluid.
Because it doesn't absorb water and isn't safety critical, in theory it doesn't need changing as often. Course that doesn't stop em at service time.

 

[Delboy777]

What are the pressure plate symptoms on a hexhead?
I've had a pressure plate fail on a car. It had a knotchy springy action and short travel. Apart from the slack, this feels normal. There is mo release bearing noise


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As the springs weaken the "fingers" of the pressure plate move away from the thrust bearing therefore lessening the action of the hydraulic system. Id check the Master cylinder first before you do anything else.

 

[Bendy toy]

Benham service think its master cylinder but seals are not available & new cylinder is well over £200. Next job strip and clean.

EDIT
They've had 1200s needing new clutch at 80K but pressure plate was ok. Early clutch changes are generally caused by driver over doing the clutch slipping or lots of off road. The latter "interesting" for an allegedly off road bike.

To answer Mike's question since the 1100 oil heads, they have always used mineral oil in the clutch


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[Steptoe]

B
To answer Mike's question since the 1100 oil heads, they have always used mineral oil in the clutch

The 1100 Gs models use a cable The 1100S and all 1150 models use Dot 4 brake/clutch fluid. The 1200 models use vitamol mineral fluid.

BMW have changed the 1200 fluid spec a few times since launch. They change the colour of the fluid each time as they aren't compatible with each other.

 

[Bendy toy]

Benham service specifically said they used mineral since the 1100. Guess he misunderstood my question.


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[Beemerman59]

Benham service think its master cylinder but seals are not available & new cylinder is well over £200. Next job strip and clean.

EDIT
They've had 1200s needing new clutch at 80K but pressure plate was ok. Early clutch changes are generally caused by driver over doing the clutch slipping or lots of off road. The latter "interesting" for an allegedly off road bike.

To answer Mike's question since the 1100 oil heads, they have always used mineral oil in the clutch


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Bendy, haven't you said on previous threads about rattly clutches that you tend to hold the clutch in when stationary to stop it rattling? Could this be connected in some way?

 

[Bendy toy]

Don't think so I never hold it for long & most of my riding is out of town. That said I've done 15K the previous owner did 33K. Who knows his habits.
The rattle only happens when gears in neutral. So must be gearbox related. If it was clutch I'd expect the noise when lever pulled in. Lever action is 100% smooth. A failing pressure plat not impossible but surely there would be a knotchy spongy action.
Yesterday I had a close listen to a low miles Mk2. It had a similar noise in neutral though lees than mine. Again no noise in gear with clutch lever pulled


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[Beemerman59]

Don't think so I never hold it for long & most of my riding is out of town. That said I've done 15K the previous owner did 33K. Who knows his habits.
The rattle only happens when gears in neutral. So must be gearbox related. If it was clutch I'd expect the noise when lever pulled in. Lever action is 100% smooth. A failing pressure plat not impossible but surely there would be a knotchy spongy action.
Yesterday I had a close listen to a low miles Mk2. It had a similar noise in neutral though lees than mine. Again no noise in gear with clutch lever pulled


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Mine rattles too - 34K miles and I've done all but 2K of those. I put up with it rattling though when in neutral. Would be nice to know how to fix it if it is possible to do do so.

 

[Bendy toy]

I'm putting up with mine but in heavy traffic I stop the engine while waiting.
New gearbox oil no change but the old oil was very clean.

When I had the sleeve cylinder off I took the push rod out and started the engine. Noise in neutral. Obviously not tested in gear ;-)


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