QuestionHi there,just in case you may know the answer...i have read a lot of the other Q's and A's in Waynes zone,but none are simliar to my problem..when i have run several kms(miles)the system heats up in some manor and THEN the hydraulic clutch won't work,leaving me stranded coming to a stop (grin) but if i stop,then its ok from the get go for awhile,but the clutch is good and strong if i speed shift while going,is the fluid heating up,newly done to try and fix the problem,cleaned out with brake cleaner and all redone,but problems prevail.might be air in system,coincidently in 06 i stopped on rd and bleed it again,but it may have been coincidental to cooling down anyway in the amount of time I was stopped to do it.Can that clutch assembly be looked at by taking a plate off under the bleeder,plates must be good inside tranny...how can i find out why the fluid hydraulic power is getting weak,is it heat that can do it,fan comes on as usual.Can I adjust the temp setting that the fan is switched on,in case it might be that.I wish I was able to hook on a preasure meter to the line to see if presure is the same after heating up.Well i hope i covered it all,please email me back in addition to posting any hints for others to read..Eric
AnswerEric... sorry about the delay. Message got lost in my email box for awhile.
Actually, I have had a similar problem with a CB550SC last year. Works fine cold, then coming off the freeway.. bike very hot... then the clutch action was gone, until I pumped it up repeatedly for a minute or two.
I do recall checking the fluid line very carefully to see where it might be contacting the engine cases or other hot sources. I did replace all the seals in the slave cylinder and the engine case area, plus carefully purged all the air out of the system. Start bleeding the system at the slave cylinder bleed nut, then the fluid line at the slave cylinder, then to go the master cylinder fitting at the end.
I think that purging the system of DOT 3 fluid and using some DOT 5 silicone fluid may be helpful, but they don't mix, so you have to clean the old stuff out thoroughly. Another consideration is that any flex lines made of rubber are now almost 30 years old and need replacing, as they will flex and expand rather than maintain rigidity under fluid pressure.
You don't need to inspect the clutch, nor try to change the fan switch settings to try to compensate for this problem. The clutch access is under the clutch cover, so you would need a new gasket on hand before you dove into that end of the engine. It is most likely a hydraulic system issue, so clean everything completely, change out all seals and add in silicone fluid, followed by a careful bleeding. The master cylinder has a bleed hole that needs to be kept clean and open, too. So check for that and/or rebuild the clutch master cylinder with a new kit.
Bill Silver
