Clutch lever gap problem.

[qbis0]

Hello,

I have problem with gap on the clutch lever.

When the engine is cold I have about 2-3mm of the gap on the clutch lever, but wen wngine is hot gap is reduced to 0mm.

My question is why is like that?? It makes that sometimes the clutch is sliding when I'm riding on 4th or 5th gear.

It looks like the presure grow up in the clutch pump when the engine is hot.

Whay is like this???

Should I disassembly clutch pump ???

I removed also the clutch release cylinder like on the screen below, and I can see that when I press home the Clutch release cylinder piston (1) by hands,

after it will Clutch release cylinder piston return back about 5mm. I think it's not normal behaviour of this part.

What's your opinion???

 

[JamesK]

Can you please start with telling us what year FJR you have?

 

[qbis0]

Can you please start with telling us what year FJR you have?

FJR 2008. GEN2

manual gear box.

 

[qbis0]

on the below picture you can see what I mean.

Why gap is reduced on hot engine???

because the fluid is more hot so volume of the fluid grow up....

 

[SLK50]

I would carefully bleed the clutch fluid if you haven't already done so, sounds like there might be a small amount of air in the system.

 

[FJRBluesman]

One, gap is measured at the clutch purch (between the purch and the clutch handle at the purch, lets call it the crotch of the clutch handle assy), not the motion of the handle.

Two, there is no real adjustment on a hydraulic clutch, aside from the handle adjuster which has nothing to do with the gap issue.

Is your clutch dragging or slipping?

Gunny bleeding the system.

 

[madmike2]

Gunny on the bleeding.

Has the fluid ever been changed? It's due.

 

[qbis0]

Yes I changed the fluid of cours for the same DOT4.

On the 5th gear when I have about 3000rpm and I want to accelerate fast,

sometime the clutch is slipping. I don't know why??? probably because lack of the clearance on the lever.

Maybe the problem is with slave clutch cylinder, because the piston is not in the maximum back position when I disassembly 3 screws.

You can see on the screen small clearance when I want to assembly (it means that piston touch the moving rod) before I use the clutch lever.

https://img195.imageshack.us/img195/5361/20100530459.jpg

https://img248.imageshack.us/img248/4599/20100530460.jpg

 

[madmike2]

To me...and perhaps only me...it sounds like your clutch is worn out. Or there's something wrong with the pressure plate.

There are owners who've replaced their clutch but usually at extended miles or bikes that are used in commuting/stop and go driving.

It really sounds more likely that something is amiss in the clutch pack rather than with the hydraulics....except for the temperature changing the clearance.

 

[wfooshee]

I agree. This looks like it is the clutch itself, not anything in the hydraulics that operate it.

And the slave piston is not necessarily supposed to be in the maximum back position. It only goes back as far as the pressure plate will push it when you release the clutch lever. Nothing pulls it back any further than that. If it is coming back further, you'd get slack like you describe, because the slave would have to move some before it engages anything.

Pressure plate spring might be relaxing when cold, but that's weird.

 

[qbis0]

Hi Everybody,

Probably I found the problem.

The problem is malfunction of the master cylinder. When I make presure the slave cylinder move forward,

but after it's impossible to push back the slave cylinder. IT's not acceptable. Normally I should be able to push back the slave cylinder using hands force.

I have to disassembly the master cylinder and change the master cylinder kit.

Anybody know some good clutch master cylinder kits???

 

[SLK50]

A two year old master cylinder shouldn't need rebuilding unless something caused it to be damaged.

The return fluid hole is very small. I would disassemble and clean the master cylinder first,

checking for something causing blockage, before buying an expensive rebuild kit.

 

[Miles Krase]

In my past 12 years of being an auto mechanic I have seen at least 50 problems similar to his complaint, only with brakes, and mostly on Hondas of all types and years. Cold everything is fine, then as engine compartment temps come up, all the freeplay in the brake pedal goes aways and the brakes begin to drag and eventually smoke. The problem has ALWAYS been a faulty master cylinder. We usually just replace the master and flush the system, unless the wheel cylinders/calipers melted. I never really looked into exactly what was going on inside, but I always suspected moisture in the system. It swells up in the master and overcomes the spring pressure in the top of the master that sets the freeplay and ends up putting mild pressure on the calipers and wheel cylinders. It doesn't take much pressure to make them smoke after 10 miles. ANYHOW, something similar may be hapening here, only down in the slave cyclinder since its nearest the engine heat. Fluid or seal expansion from moisture ends up putting pressure on the pressure plate and makes the clutch start slipping. If it were me, I'd flush the system, throw in the piston seal, #3 in the pic, and maybe even the pistion, cylinder and spring if they don't cost much, refill and bleed the system. I have a really good feeling this would fix your problem. The clutch pressuure plate is retained with screws (8 or 6, I can't remember) so the odds that they are all lossening up and allowing the plate to release and take up the freeplay is pretty slim, although that would make it slip as well. Of coarse this is just my .02, or .03 since it was a little long....I tend to ramble!

 

[madmike2]

I once had a similar brake drag problem with another bike. I took the master cylinder apart and cleaned....NOT the solution. I read that there are 2 return holes for the brake fluid. A large one and a tiny one. Evidently the tinier hole balances the pressure on both sides of the piston/seal assembly until the piston passes this hole. I made a small 90 degree awl from a paper clip and cleaned the splooge from the small hole. After that everything was normal.

MAYBE the same situation exists with the clutch master cylinder. If there was an accumulation of moisture and it plugged the hole....

When you dis-assemble the master cylinder look very carefully for 2 return holes to the reservoir.

The repair manual doesn't have detailed pictures of the cylinder bore.

 

[Miles Krase]

Good call Mike. Maybe thats been our problem all along.