I'm baffled, clutch issue...

The clutch will not engage. I have a '86 VFR700F2. I have done everything that I found in the search. Drained and back filled the system using a 60ml syringe. Took the slave out and made sure it was free. Dismantled the master and cleaned it really well. When I back filled fluid came out of the little hole in the master with no problem. Just pulled the slave housing off without disconnecting the hydraulic line or opening the bleeder. When I squeeze the clutch handle I can hold the slave cylinder in with my thumb. There is pressure but not much at all, surely not enough to activate the clutch plate. I am just baffled so any ideas would be appreciated. It is 70 degrees today in Pennsylvania.
Thanks

 

Have you tried rebuilding the clutch master. It sounds like it might have fluid bypassing the piston causing the low pressure at the slave. Rebuild kits are only about $30. Might be worth a try. good luck

 

I modified my clutch secondary cylinder mounting application, cause I was having issues. Course, that was mainly because that whole steel around the thread holes were “toe up”, after my chain broke, and doubled back on itself, then forced itself through my drive sprocket. That was a fun 3 months.

I will take a close up pic of it tonight when I get home and post it.

Here is what I found. Because the 5 springs in the clutch basket, once the system is old and sort of wore out, it becomes harder for the clutch slave cylinder to force the clutch rod over, and compress the clutch plates. I reinforced the “mounting application” of the secondary cylinder by adding a back up bracket to cross the cylinder, and use the existing bolt hole pattern of the sprocket guard, via simply exchanging out two bolts for longer ones. (CAUTION! Remember! Those bolt threads are metric)

You can check your bike by doing what I did. Get a 6 inch straight edge, or use a tape measure if you HAVE TO. But you want to measure any deflection of the secondary cylinder. Crouch on the side of the bike and get very close so you can check it. Hold the straight edge against the engine, and through the slots in the sprocket guard, as close to the secondary cylinder as you can. Pull the clutch repeatedly, and observe for any deflection. If you have quite a bit, you may want to add the brace, as I did. If not, then you either have air in your clutch lines, a hole in your clutch hose, or you need to rebuild the seals in the master and secondary cylinders.

If you want to get real dirty, you can remove your clutch secondary cylinder, and expose the clutch rod. Using a prybar, set the tip against the kickstand bracket, and put a piece of metal between your prybar and the clutch rod. Manually move the clutch rod to ensure your clutch plates aren’t frozen up.

 

Photos as promised.

 

Use a pair of locking pliers and clamp the rubber line about 6" from the MC. The lever should feel rock hard. If it doesn't, then you know that the MC is the issue.

Use this method to test the system - working your way down to the slave cylinder.

Put a rag over the hose before you clamp it. You don't want to deform the hose.

Of course, if you have SS lines, this won't work.