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Discussion Starter #1
Bike is an 2008 F4 1000R with 40,000 Km
Symptoms:
Out for a ride and bike becoming increasingly difficult to near impossible to change gears, cannot find neutral.
Bike will not stop with engine running, in short I could not disengage the clutch and am having severe clutch drag.

I Manage to nurse the bike home and start investigating. Clutch pack not moving when the clutch handle is pulled in. I notice fluid around the Clutch slave. It seems my clutch slave has developed a leak, the clutch fluid reservoir is empty...no problem, I have an Oberon clutch slave that I ordered a while back and never got around to fitting, so I change out the clutch slave for the oberon. Bleed the clutch as per Noels method. Symptoms have improved but still got a dragging clutch. The bike still drives the rear wheel when in gear and clutch handle pulled in, up to 15km/hr.

I do some reading and it seems if the master cylinder seals are shot it can lead to clutch drag. I had some seals that I got when I was rebuilding the rear brake master cylinder, they are the same size so I have put them in the clutch master using the original piston and spring. no change to the clutch drag. I Have a look in the oil filler hole and can see the clutch pack moving when the clutch handle is pulled in but I'm not sure how much it is supposed to move.

I will need to inspect the clutch. I remove the clutch cover housing and inspect.
Springs measure 54.6mm ( according to the manual the service limit is 53mm, I'm not sure if this means they are within spec or not, can anyone enlighten me?)
Friction plates measure within spec
I could not find a spec for the metal plates but noticed a blue ting on almost all the metal plates, Is this heat damage?
Both friction and metal plates are checked for flatness on a Glass table and are flat.
The clutch hub/basket/pressure plate seem ok, i.e., no broken bits.

My question is do I need new clutch plates and springs due to the clutch being overheated? I have uploaded some photo's I took along the way, if you need more to help me I am happy to take more photo's. Any help would be appreciated.
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The springs shorten as they lose tension, so that is not the issue.
I suspect the issue is there is not enough stroke to separate the clutch plates. The issue is between the master and slave cylinder. Are you sure there is no air in the system - air will compress so you will efficiency?

Make sure you put the first cone shape washer in the correct orientation btw.
 

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+1 Flush the line with fresh fluid and remove all air. Carefully inspect the mc reservoir. OEM mc?
 

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Discussion Starter #4
The springs shorten as they lose tension, so that is not the issue.
I suspect the issue is there is not enough stroke to separate the clutch plates. The issue is between the master and slave cylinder. Are you sure there is no air in the system - air will compress so you will efficiency?

Make sure you put the first cone shape washer in the correct orientation btw.
I am as sure as I can be that there is no air in the system.
Thanks for the info on the springs
 

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Discussion Starter #5
+1 Flush the line with fresh fluid and remove all air. Carefully inspect the mc reservoir. OEM mc?
The line has been flushed and bled with fresh fluid twice now.
MC reservoir is stock, I have had it apart when I fitted the new seals. The only seal not changed is the O ring that sits directly below the reservoir as I did not have one of those but it seemed in good condition with no indication of a leak.
 

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Discussion Starter #6
The metal plate in the photo above has a blue tinge around the outside circumference. Is this normal or an indication of overheating the clutch? it is on almost all the metal plates.
 

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Hi,
Carefully and evenly smooth out the rumble quirks from the outside and inside of the clutch basket, which prevent the clutch linings from sliding easily and therefore don't separate easily.
 

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A small amount of discolouration on the metal plates shouldn't be the cause of your problem provided they haven't warped. On my 750 the plates had discolouration from heat. I touched them up on glass with a little bit of wet and dry to ensure flatness. I would go with the clutch slave not having enough throw due to air in the system. Triple ckeck your bleed
 

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Discussion Starter #9
A small amount of discolouration on the metal plates shouldn't be the cause of your problem provided they haven't warped. On my 750 the plates had discolouration from heat. I touched them up on glass with a little bit of wet and dry to ensure flatness. I would go with the clutch slave not having enough throw due to air in the system. Triple ckeck your bleed
Ok, I will bleed the system again, maybe borrow a mittyvac type tool to do it and reverse bleed as well. I will let you know how I get on. Thanks to everyone for their help.
 

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Your plates are fine if they are flat...as mentioned previously, discoloration is not a problem. Warped is.
Pressure plate only needs lift a millimeter or so for disengagement.
As previously mentioned, spring service limit is minimum length, longer is better.
Oil viscosity (and just cold oil) can contribute to clutch drag.
Good luck.
 

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Discussion Starter #11
Your plates are fine if they are flat...as mentioned previously, discoloration is not a problem. Warped is.
Pressure plate only needs lift a millimeter or so for disengagement.
As previously mentioned, spring service limit is minimum length, longer is better.
Oil viscosity (and just cold oil) can contribute to clutch drag.
Good luck.
Thanks for the info, what I am experiencing is not viscos drag. I will bleed the system again when time allows. I will update as I go.
The pressure plate is currently shifting 2-3mm when lever is depressed. Thanks again for the help.
 

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Discussion Starter #12
I reverse bled the clutch today, (this is how i usually bleed my brakes, I dont know why i didn't reverse bleed the clutch to start with) although I didnt see any bubble coming out, I probably missed them, the problem has resolved.
A big thanks to you guys and the forum for the assistance and direction given. I thought I was looking at new clutch kit.

Just on a side note.
The price of an OEM gasket for the clutch cover is disgusting, Thats if you can find one in Aus. I could have ordered one but it was a 6 week wait for it to come from Italy. I ended up using the red RTV silicone gasket in a tube stuff as advocated by many on here.
 

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Cool. Good job. Go ride!
 
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