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Discussion Starter #1
hi all
stripped the bike down and put a complete clutch in but seem to have a problem it seems to be slipping
anybody had this problem

replaced clutch plate
spring plate
pressure plate
push rod felt pad
all gearbox seals
and main crank seal

all parts from bmw works in the uk

clutch seems to be right at the end of the lever slight pull on lever and it will slip

thanks to all for all your help
 

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Discussion Starter #2
hanks for your reply

its as if the cylinder is pressing on the pressure plate and not releasing all the way of

the bite point on the clutch lever is right at the end of the lever and a small amount off pressure on the lever will slip the clutch

when riding if the bike is under load and hard acceleration the clutch will slip

hope this helps thanks
S
 

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Wrencher Extraordinaire
2005 K1200LT
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14,108 Posts
Like I said on the other post do you recall when you installed the slave cylinder, was it very close to the housing before it bottomed out on the rod or was it out quite a ways away. It should have been almost in contact with the transmission housing on a properly installed new clutch.
 

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Wrencher Extraordinaire
2005 K1200LT
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14,108 Posts
That is correct on the slave. The only other thing could be some air in the line. Try tying the clutch lever about half way to the grip and leave it over night with that grip elevated (bars turn to the right). See if that makes a difference. My clutch releases after less than 1 inch of travel on the lever. That is the best part of a hydraulic actuated clutch the lever position never changes as the clutch wears.
 

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what works for me sometimes, is to put something over the return hole in the reservoir... so the brake fluid doesn't get all over.( I use an American quarter ).... And pull the clutch in and let it go .Sometime I just pull the clutch in a little then let it go... Sometimes the bobbles will come out , it kind of helps get them to rise to the top.:wave
 

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Something must be the cause. Possibilities are: Contamination. Did you use a spline lube and how much? enough to have a gob of it fall into the clutch? Did you thoroughly clean the clutch plates as they usually come coated with something to prevent rust. Possibly a defective disk being too thick or too thin? Let me see if I can get this right. Did you happen to measure the new disk as all of us would have :nerd: just kidding but if it was too thick, the push rod would have been too short and the clutch would not disengage depending on how much too thick. Too thin and there wouldn't be enough pressure to prevent slipping plus the push rod would be long maybe preventing engagement at all. It gets longer as the clutch wears. John asked if you put the coat hanger wire back under the spring before assembly. Is it still in the old part or did it make it into the new assembly. There isn't too much else that would cause this.
 

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Something must be the cause. Possibilities are: Contamination. Did you use a spline lube and how much? enough to have a gob of it fall into the clutch? Did you thoroughly clean the clutch plates as they usually come coated with something to prevent rust. Possibly a defective disk being too thick or too thin? Let me see if I can get this right. Did you happen to measure the new disk as all of us would have :nerd: just kidding but if it was too thick, the push rod would have been too short and the clutch would not disengage depending on how much too thick. Too thin and there wouldn't be enough pressure to prevent slipping plus the push rod would be long maybe preventing engagement at all. It gets longer as the clutch wears. John asked if you put the coat hanger wire back under the spring before assembly. Is it still in the old part or did it make it into the new assembly. There isn't too much else that would cause this.
I was thinking much the same. I did measure my rebuilt clutch disk as I had read about issues with some cheap Chinese ones being too thick. I was thinking lube contamination also as that is what caused me to rebuild mine. However, it is hard to imagine getting enough excess spline lube to cause a problem. My clutch held under all but the highest torque conditions and it had at least 50% of the friction material soaked with gear oil. Hard to imagine a glob of grease causing that much issue, but it can’t be ruled out as a cause. It sure sounds like a tolerance issue somewhere. I measured all of the dimensions that I had read about here on the forum (mainly friction material thickness and pushrod protrusion past the slave mounting surface and mine were all in spec. It sounds like it is time to pull the clutch slave and measure the pushrod protrusion again.

I also don’t see how air in the system would cause slippage. It seems to me that air would prevent disengagement of the clutch rather than engagement. It seems that either the disk has to be too thick or something in the clutch slave is not allowing it to fully retract. Other than the metal parts also being out of thickness tolerance, it is hard to think what else would cause the issue. Although, the wire behind the spring plate is a candidate also. I think it is one the “push” side of the spring which means its omission would greatly reduce the spring’s tension. I know I was concerned about getting mine in place properly, but a little grease seemed to stick it pretty well as I recall. It is hard to believe it has been 3 years since I did my clutch and I am already forgetting many of the finer details.
 

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I was thinking much the same. I did measure my rebuilt clutch disk as I had read about issues with some cheap Chinese ones being too thick. I was thinking lube contamination also as that is what caused me to rebuild mine. However, it is hard to imagine getting enough excess spline lube to cause a problem. My clutch held under all but the highest torque conditions and it had at least 50% of the friction material soaked with gear oil. Hard to imagine a glob of grease causing that much issue, but it can’t be ruled out as a cause. It sure sounds like a tolerance issue somewhere. I measured all of the dimensions that I had read about here on the forum (mainly friction material thickness and pushrod protrusion past the slave mounting surface and mine were all in spec. It sounds like it is time to pull the clutch slave and measure the pushrod protrusion again.

I also don’t see how air in the system would cause slippage. It seems to me that air would prevent disengagement of the clutch rather than engagement. It seems that either the disk has to be too thick or something in the clutch slave is not allowing it to fully retract. Other than the metal parts also being out of thickness tolerance, it is hard to think what else would cause the issue. Although, the wire behind the spring plate is a candidate also. I think it is one the “push” side of the spring which means its omission would greatly reduce the spring’s tension. I know I was concerned about getting mine in place properly, but a little grease seemed to stick it pretty well as I recall. It is hard to believe it has been 3 years since I did my clutch and I am already forgetting many of the finer details.
air in the line might have some effect if the screw on the hand leaver had been turned in too far not allowing fluid to return to the reservoir to purge it out but more likely would be a spongy handle. Fluid might cause this as it expanded from heat in the same condition with no where to go.
 

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Discussion Starter #12
hi all thanks for all your replys

seem as the fluid return to the reservoir is blocked or part blocked it seems when the bike has been stood its fine

but the more the clutch is used the more the clutch will slip

so thinking the return back to reservoir could be part blocked

what would the best way of sorting this be any help would great

thanks dave
 

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hi all thanks for all your replys

seem as the fluid return to the reservoir is blocked or part blocked it seems when the bike has been stood its fine

but the more the clutch is used the more the clutch will slip

so thinking the return back to reservoir could be part blocked

what would the best way of sorting this be any help would great

thanks dave
If the line hasn't collapsed internally which has happened before, I would back off the screw in the hand leaver or make sure that it isn't applying any pressure when at rest but be aware that mine is completely buggared with red locktite so if I ever had to do any adjustment, it would probably have to take a blow torch to it off the bike somewhere away from melty things like rubber seals and such. The clutch line is not a cheap part if you have to replace it. It comes in what looks like 3 pieces based on ther MAX BMW fiche and is the same for the 99-09. WOWZA!

04 21 52 2 333 450 PRESSURE HOSE ASSY.CLUTCH 0.19 1 $192.95
05 21 52 2 333 451 PRESSURE HOSE ASSY.CLUTCH 0.12 1 $192.95
08 21 52 2 333 308 CLUTCH VENT PIPE 0.10 1 $142.95

If the ends are in good shape and it is deteriorated and blocked, you may be able to find a hydraulic shop to remake them much cheaper. That size banjo ends with those bends are not readily available as I have looked awhile ago and no dice where I managed to look. Someone else may have better luck in searching.
 

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Wrencher Extraordinaire
2005 K1200LT
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You could also just push some fluid up from the lower bleed port at the end of the hose on the right side of the bike. If fluid flows easily up and fills the reservoir then the line and the fluid return vent is clear. Usually that vent is closed with the lever in the rest position and opens (with a squirt so protect the painted bits) as you just start to squeeze the lever.
 

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I had one the more you use it the more it would slip. It ended up being the clutch master cylinder, I got lucky all I did was clean it out and flush it. Ever body does there brake system but very few do the clutch system. As far as the lines Spiegler can make them up.
 

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I had one the more you use it the more it would slip. It ended up being the clutch master cylinder, I got lucky all I did was clean it out and flush it. Ever body does there brake system but very few do the clutch system. As far as the lines Spiegler can make them up.
Is this a custom thing as I have never seen clutch lines listed from Spiegler anywhere. Do they provide new banjos or do you have to send them your old ones?
 

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You could also just push some fluid up from the lower bleed port at the end of the hose on the right side of the bike. If fluid flows easily up and fills the reservoir then the line and the fluid return vent is clear. Usually that vent is closed with the lever in the rest position and opens (with a squirt so protect the painted bits) as you just start to squeeze the lever.
I don’t think I’ve ever seen a master cylinder that closed the bleed port in the released position. That is strange. So, you have to pull the lever in a little in order to push fluid up from the bleed port? That just seems wrong.
 

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Wrencher Extraordinaire
2005 K1200LT
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I don’t think I’ve ever seen a master cylinder that closed the bleed port in the released position. That is strange. So, you have to pull the lever in a little in order to push fluid up from the bleed port? That just seems wrong.
You are right I had it bass ackwards. The little squirt is fluid being pushed by the MC piston until it CLOSES the vent. Thanks Matt. So the vent should be open at rest and fluid should flow up if you push it in from the bleed port unless there is a blockage.
 

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You are right I had it bass ackwards. The little squirt is fluid being pushed by the MC piston until it CLOSES the vent. Thanks Matt. So the vent should be open at rest and fluid should flow up if you push it in from the bleed port unless there is a blockage.
OK, that seems consistent with what I have seen in the past. That is how these units self-adjust. The amount of fluid in the system under pressure is determined at the point the bleed vent hole gets closed by the piston. When the lever is fully released, the slave can move to whatever position it desires and suck in or expel any amount of fluid needed to accommodate wear and then once the master position moves past that port, the correct volume is in the system and feels the pressure.

Now, if the master cylinder piston is sticking and not retracting fully, that would not allow the system to self-adjust...
 
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