GSX1100g slipping hydraulic clutch

[gandy666]

hello there,

have a strange issue with the hydraulic clutch on my GSX1100g.

I've had it about 2 months, it was in storage for a year or so. Clutch has been fine up to this point, but have been using the bike in anger for the last 2 weeks, doing about 80 miles a day. had no issues up until friday when there was no pressure on the lever at all. closer inspection revealed that the reservoir was empty and the fluid had turned into a kind of waxy oily stuff.

so i cleared all the oil out of the pipe by blowing through, bled it though, took the slave cyclinder off and cleaned that thoroughly as well, then checked the spring and all seemed well, put it all back together,took the bike to work this morning and all was well.

brought it back tonight and the clutch started to slip after about 35 miles, so was thoroughly warmed up. Plenty of tension still on the lever, I'm thinking that the fluid has warmed up, expanded and is engaging the clutch without me actually putting pressure on it. I changed the oil in the bike about 4 weeks, using synthetic motorbike oil (Motol 5000 10w40) so I dont think the oil is to blame.

I'm thinking it will be fine tomorrow once it cools off, then will start slipping again when it warms up.

I cant find a method of adjusting the clutch as it just engages a lever that activates the clutch mechanism?

has anyone ecountered this kind of thing before?

I was thinking I would open the bleeder nipple when the bike is warm this morning, without pulling the clutch lever to relieve some pressure but the assumption is as soon as I pull on the lever the pressure will go back up and I'll be back to square one.

wondering is the master cycllinder should perhaps have a small valve somewhere that releases pressure in the case of fluid warm up and perhaps that is blocked?

any help appreciated.

cheers!

[Stu]

The fluid won't expand under heat not only that once the lever is released there is no pressure on the slave and the fluid is free to flow back to the res so if the fluid did expand then it would just go back in the res

[gandy666]

thanks for the reply stu.

would that suggest that if the 'hole'that allows the fluid to flow back in res was blocked it would cause the symptoms I'm seeing?

or if it were blocked I'm thinking the clutch would be engaged constantly cos the pressure was not being released.

only happened for the first time tonight so not sure how its going to be tomorrow.

clutch has been absolutely fine until I put new hydraulic fluid in it then bled it through. assumption is if there were air in the line, pulling the lever would barely engage it.

this appears to be the opposite problem - or perhaps the clutch is slow to release because the push road is sticky with crap.

if i remove the bolts that hold the slave cylinder to the push rod, is the piston likely to pop out? or if i removed the reservoir cap, will that release the pressure so I can take out the push road without having to worry about re bleeding and fluid all over the place? pretty sure the system has been properly bled and there's no air in it

[Tango]

Not just the clutch plates are on their way out....and it's just one of those coincidence things?

Obviously though if the push rod is sticking that could cause the problem....but it would tend to do it all the time unless its heat that is causing it to stick. Did you replace the seals or just clean them?...... If you didn't, I'd be inclined to replace the seals and try again.....

[rennie]

Is the new synthetic oil too good for a bike of that age?

I have no idea! only thinking out loud

[gandy666]

checked the seal - it was absolutely fine.

cleaned out the caliper pot as well - was a small ridge of dried crap - now its completely smooth. lubricated all over with brake fluid and checked for leaks under pressure before re fit/

thinking if it was the oil it would have happened before now- changed it weeks ago.

oil was semi synthetic and proper bike oil - not car oil or anything

[gandy666]

for anyone still following this, it turned out to be the return hole into the master cylinder reservoir was blocked when the hydraulic fluid went off and turned to jelly, plus the master cylinder piston was not returning to rest properly to allow fluid back into the res, plus the friction plates were worn.

so a combo

[mattycoops43]

Glad you got it sorted, it's always a pain in the rear when it's a combo of minor things like that!