Clutch Barely Engages - 1998 VFR800

So I just started getting bike ready for the season. I rode it once roughly 2 months ago and all was fine. I did noticed towards the end of last season that the Brake reservoir on the left side of the handle bar (side with clutch lever) needed fluid, as it was almost out. Today, I grabbed the lever and it had no resistance. I went to take the top off the reservoir and one screw was stripped. So, I used a screw extractor and got it out. I added fluid to fill line and put the top back on. Turned on the bike, and the clutch lever has not gotten any resistance back.

What I mean is that I pull the clutch lever all the way to the handle bar and it barely engages the clutch. It does engage at the very last 5-10%, but there is almost no friction zone. I have not ridden it since it last worked, and it just sat in garage on battery tender, so I don't know why clutch would have failed.

Any ideas would be helpful. Thank you!

 

By letting it run down (likely a leak you should address) you let air in the system. Adding fluid above it just puts an air pocket in the system. They need to be bled.

 

Thanks for the tip. I started thinking that was the issue as I was doing some research a few minutes ago. I will bleed them. Do you have to bleed them with a bleeder vacuum, or can I just attach hosing to bleeder valve and pump/hold clutch til no bubbles in line?

 

Based upon the explanation of your specific situation, If the system has a leak and air has gotten into the existing fluid, I would first recommend that you perform a visual inspection to see if you can find any signs of fluid weeps, drips, or leaks. Check each banjo bolt connection, look around the rubber seals of the master and clutch slave cylinders. Sitting for long periods, the rubber bits get brittle and shrinks. If you can't see anything, I would recommend giving the system a good flush. If air has gotten into the system, brake fluid will abosrb moisture contained within the air and contaminate it. For a complete drain, flush, refill, initial bleed, you are going to need a vacuum bleeder. The lever only moves a very small amount of fluid and you will drive yourself crazy trying to do it with the pump, hold, bleed method.

 

^^^ for a good clutch bleed it's usually helpful to remove the front sprocket cover [or just the slave] and fully retract and hold back the slave piston using a C-clamp so no air can hide behind the piston.

 

^^^That's also a good way to check that the piston seal isn't leaking fluid.

 

Mostly good advice, but I'm using the ol' pump, and bleed method. I just installed new clutch line with the new Hurricane bar kit, and it was no big deal. I've never had very good luck with the vacuum bleeder anyway. It usually leaks air past the bleed screw threads.

 

I use no pumps or vacuums. Just more to clean from my experience.

 

The fact you had to add fluid would have me concerned. That shouldn't need topping off.

If there's no obvious leaks up at the handlebar, I would pull the slave cylinder. Three bolts secure it, check the shop manual. Pull it carefully and make sure the shift rod frees from the middle of the piston. You might find that's where all the fluid has gone. The piston seal can crack over time, or the piston can develop pitting from moisture and crud. Either scenario will prevent a seal and fluid will escape when grabbing the lever. The fluid will be escaping between the piston and the cylinder housing. You might even find some pooled up in the recess of the sprocket cover where the slave cylinder gasket lives.



Also, those screws on the reservoir lid covers are JIS, not Phillips. Using a regular Phillips bit will mess them up.

 

Fixed, now broken again

So I bled the system and got it working but did notice the slave cylinder gasket was ripped apart. So I bought a new gasket and installed it. After installation my clutch had 0 resistance. I bled again for 15 minutes and never got it to get resistance on clutch. Not sure next step.


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Is the clutch good? Is fluid coming out the other end? This hydraulic system could not be simpler. Lever pushes plunger. Plunger pushes fluid through single hose. Fluid pushes plunger on other end. Clutch moves. Can you verify that any of that is happening also?

 

first, unbolt the clutch m.c. from the bar and hold it vertically by the lever while tapping the banjo bolt area.

if that doesn't help.......

you can try reverse bleeding, injecting fluid by means of a syringe into the bleed nipple on the slave.

 

When I used my pump vacuum bleeder I did get fluid out the other end and had to refill reservoir at clutch handle 1-2 times during the process.


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Thanks for the tip. Will have to try this but need to look up some of those things. I’m not the most versed on everything, so I apologize. Not sure what “clutch m.c. From the bar” is or the banjo bolt.


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how utterly inconvenient. so you live in not-a-mechanicsburg ?

 

Is there a good motorcycle shop you could have look at this for you?

 

Yes, I have one nearby that does my inspection. Trying to save the money but will if I need too. Will try the tapping bolt and bleeding again.


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Possible the master cyl didn't prime properly, but if you were able to bleed it, then it probably did..... try tying the lever to the bar overnight and re-bleed in the morning, see how it goes.

 

What would be the mechanical reason this may work? Just wondering? I’m confused how liquid is pumping through but there is no resistance. So even when I pull the clutch all the way in the back tire still loves some becuase clutch don’t fully engaging.

Could it be a bad slave cylinder?


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If you drained it to replace/refurb the slave cylinder, if you had drained the master cylinder, you'll have to re-prime it. If it's pumping fluid out the bleeder, then it is primed. You can remove slave and see if piston is moving while you pump. If so, then pull the clutch rod out, clean it, grease it and reinstall it, as it may be sticking??