Hi all just replaced my clutch and rebuilt the slave cylinder, bled the clutch up using a vacuum bleeder , lever felt fine. Noticed a tiny bit of drag when in gear and hand on the clutch. Thought it maybe because the clutch is new and needs a run in. Took it to the shops today not far and it seem to get worse. I replaced the clutch springs with “ heavy duty “ listed ones. Anything common or best ways to bleed ? In case it’s still air ? Thanks
Clutch drag
- Thread starter PaulCovy
- Start date
STraymond
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I had the same problem when I installed new clutch parts on my ST1100. I found that the “ears” on the new clutch friction plates were too “sharp” and would not spin freely inside the clutch basket when the clutch was engaged.
Filing a very small amount off of the metal ears solved the problem.
Filing a very small amount off of the metal ears solved the problem.
Two easier possibilities worth investigating.
1 . Could still be air in the lines - if the movement of the lever is squashing air, then it isn't disengaging the new springs with heavier springs.
When bleeding, pump the lever a few times to build up a bit of heat and pressure in the lines and then hold the lever in place against the bars. Then slacken the bleed valve and tighten it again before the fluid/air stops moving through the bleed tube. Repeat lots of times.
Reason: normal bleeding doesn't get rid of any air trapped around the new slave cylinder. Doing the above pushes the slave cylinder in, and it is the returning slave that pushes the fluid out.
There is also a possibility that there is a bit of air around the lever banjo union. It can be burped by slackening off the bolt and pumping the fluid - use a cloth to catch the escaping fluid. It is for this reason that after having the lines off the bike, I never tighten them up against the new washers to the full torque value. I'll tighten them to (say) 20Nm, bleed, burp, and then tighten them up to the correct value.
2. It could be a worn brass bush in the clutch lever. It has a blind hole in one side of it and the pushrod fits into this hole. It wears and it possible for it to wear all the way through. But before that, the hole is deeper than when new. And that means it cannot push the plunger in as far as it should.
1 . Could still be air in the lines - if the movement of the lever is squashing air, then it isn't disengaging the new springs with heavier springs.
When bleeding, pump the lever a few times to build up a bit of heat and pressure in the lines and then hold the lever in place against the bars. Then slacken the bleed valve and tighten it again before the fluid/air stops moving through the bleed tube. Repeat lots of times.
Reason: normal bleeding doesn't get rid of any air trapped around the new slave cylinder. Doing the above pushes the slave cylinder in, and it is the returning slave that pushes the fluid out.
There is also a possibility that there is a bit of air around the lever banjo union. It can be burped by slackening off the bolt and pumping the fluid - use a cloth to catch the escaping fluid. It is for this reason that after having the lines off the bike, I never tighten them up against the new washers to the full torque value. I'll tighten them to (say) 20Nm, bleed, burp, and then tighten them up to the correct value.
2. It could be a worn brass bush in the clutch lever. It has a blind hole in one side of it and the pushrod fits into this hole. It wears and it possible for it to wear all the way through. But before that, the hole is deeper than when new. And that means it cannot push the plunger in as far as it should.
I put a new clutch in my 1999 VFR800 recently (TRK brand friction plates from Wemoto) and experienced something similar. I know the hydraulics are perfect, but the clutch just barely disengages enough to shift back to neutral at a standstill. I adjusted the lever span to maximise the slave action and it is certainly better but unless I have the lever pulled hard in, neutral is elusive. This is not a riding issue however, and it does seem to be getting better with use. My assumption is that the friction discs are thicker (or possib;y less uniformly flat) than they used to be and exerting a bit more drag on the steels, and that wear is helping.
I did something similar (new friction discs, same parts source) to my 07 VFR800 and had no issues at all.
I did something similar (new friction discs, same parts source) to my 07 VFR800 and had no issues at all.
The clutch I got was a trk from wemoto also
Also check to make sure that the clutch lever pivot is not worn out - this can cause the lever to not fully depress the master cylinder piston. Also check that the small plunger pin is centered in the master cylinder piston assembly. I've seen plenty of these come out.