Clutch question

[Kybronco]

2004 midnight venture 1300. Left home tonight to ride bike to work. Everything working as it should. Rode interstate 48 miles and got off my exit but when I downshift It didn’t want to shift: finally came to bottom of ramp and felt bike creeping forward with clutch in. I made it to parking lot at work. What could it be ?

[RDawson]

Check fluid level. The culprit is often a leaking slave cylinder. How old is the fluid? Old dark fluid needs to be flushed if present. 

[Kybronco]

Thanks buddy I supposedly had that mechanic check and change all fluids. Is the reservoir on the clutch handlebar side? Should I just top it off to get home or limp it home and bleed it ? Thanks 

[RDawson]

11 hours ago, Kybronco said:

Thanks buddy I supposedly had that mechanic check and change all fluids. Is the reservoir on the clutch handlebar side? Should I just top it off to get home or limp it home and bleed it ? Thanks 

You can try topping it off but you’ll probably have to bleed it too. Look for oil spots under the bike, the slave usually drips there. 

[Kybronco]

So last night I parked it until I got off work. Went over to bike and looked into the oil level glass but to tell ya the truth it’s so discolored I can’t see the level clearly. Next I squeezed the clutch and it felt normal again. So I put it in neautral and started her up. Clutch seemed to fade a bit as I got close to home about a 50 mile trip. So anyway I made it and I’ll be flushing her out this weekend. I hear it’s gonna rain so good indoors project. 😁

[Squidley]

It sounds like the fluid is contaminated with water. Brake fluid is hygroscopic and will absorb moisture. When it heats up from riding it's less effective at compressing properly so the clutch, or brakes will fade. I'd be willing to bet a fluid flush and insure it's sealed properly will take care of it.

[Kybronco]

You are right , I removed the cover and saw the fluid was a dark brown with some black floating on top . Also noticed some gunky material stuck to the side. I’m gonna give this bike a good going over which I should have done anyway. Thanks to everyone for the comments and help.

[craigatcsi]

My trike started this exact same behavior last week! I made it home okay, but won’t take it out again like that.

I had it in to the service dept. last fall because shifting was bad. They flushed the “very bad” fluid and it shifted like new again!

So, I need to have it hauled back out to them.

Edited July 30, 2021 by craigatcsi

[Bob K.]

On 7/17/2021 at 7:20 PM, Kybronco said:

You are right , I removed the cover and saw the fluid was a dark brown with some black floating on top . Also noticed some gunky material stuck to the side. I’m gonna give this bike a good going over which I should have done anyway. Thanks to everyone for the comments and help.

Yup, my money's on broken-down fluid.  There's clutch fluid down at the clutch that is exposed to lots of engine heat.  Over time, this breaks down the fluid and it can no longer perform its hydraulic function.  This happens on my bike every so often:  It was o.k. when cold but as soon as the motor and fluid got hot, the clutch would start to fade.  I'd have to pump it up several times before quickly shifting gears and put it in neutral at stop signs in order to get it home.

Suck out or sop up the old fluid in the reservoir.  Refill with new fluid and bleed away until it's nice and clean at the bleeder.  I'll bet everything ends up back to normal.

Edited August 6, 2021 by Bob K.

[skydoc_17]

Hey Guys,

I personally flush my brake and clutch fluid YEARLY! The DOT3/Dot4 fluid our bikes use is rated to 500 degrees. (which is well in the range of normal braking temps.) Unfortunately, the clutch slave is located at the rear of the engine, close to the exhaust pipes and starved for fresh air. Because the fluid attracts moisture, and the reservoir is vented, water builds up at the clutch slave because it is the lowest point on that system. The heat boils the moisture, creating air bubbles, and this is why the clutch fades. When the clutch system cools off, the air bubbles are absorbed and the fluid functions again. This is not a hard service to do although it does help if you have a "helper" to work the clutch or brake lever while you work the bleeder. My children as young a 7 years old helped me bleed the fluid every spring. They also learned about regular maintenance on a vehicle at a very early age. This has served them well now that they are adults. Invite a few riding buddies over, provide the beverage of choice for the group, throw a few dogs on the grill and bleed everyone's brakes and clutches. It works every time for me! But even if you have to take it to a shop for this service, it does need to be done every year or two. The results of not doing it are damage to the clutch friction discs and clutch plates. It's cheaper in the long run to service the fluid than it is to replace the clutch!

Earl  

[luvmy40]

2 hours ago, skydoc_17 said:

Hey Guys,

I personally flush my brake and clutch fluid YEARLY! The DOT3/Dot4 fluid our bikes use is rated to 500 degrees. (which is well in the range of normal braking temps.) Unfortunately, the clutch slave is located at the rear of the engine, close to the exhaust pipes and starved for fresh air. Because the fluid attracts moisture, and the reservoir is vented, water builds up at the clutch slave because it is the lowest point on that system. The heat boils the moisture, creating air bubbles, and this is why the clutch fades. When the clutch system cools off, the air bubbles are absorbed and the fluid functions again. This is not a hard service to do although it does help if you have a "helper" to work the clutch or brake lever while you work the bleeder. My children as young a 7 years old helped me bleed the fluid every spring. They also learned about regular maintenance on a vehicle at a very early age. This has served them well now that they are adults. Invite a few riding buddies over, provide the beverage of choice for the group, throw a few dogs on the grill and bleed everyone's brakes and clutches. It works every time for me! But even if you have to take it to a shop for this service, it does need to be done every year or two. The results of not doing it are damage to the clutch friction discs and clutch plates. It's cheaper in the long run to service the fluid than it is to replace the clutch!

Earl  

This where a vacuum bleeder setup really shines. Hose to the bleeder valve from the vac trap. Open the MC, Pull a good deep vacuum, Crack the bleeder valve and just add fresh fluid to the MC as the vacuum trap fills up.