clutch bleeding

Take the slave off, disconnect the hydraulic line. Use an air gun and carefully keep squirting small burst of air into the slave thru the clutch line attachment point. Just be sure to point it away from you, have something soft for the piston to fall out on....like a little pile of rages. Just don't hit it too hard with the airgun, or you could shoot the piston across the room and damage it. ON re-assembly, lube the new seals, get it centered in the slave cylinderand push the piston in from the center.You can just pull the clutch acuator rod out of the engien and stick that in the center of the piston where it would normally fit and use that to push the piston back in.

 

I know this is an old thread, however, this seems to be a common problem and FAQ, especially on older bikes.

I have an 87 VFR700 F2 Interceptor, which I have rebuilt from LITTERALLY a frame, 2 wheels, and an engine. I have learned a ton about this bike, and am almost fluent with the majority of its workings. The bike has over 58K miles on it, and has been through 2 fires, and 3 wrecks...never totaled.

6 months ago, my original chain broke, and the backlash, doubled the chain back on itself twice. Trying to run that through the sproket, destroyed that entire area of the engine, plus damaging 2 bolt holes to beyond repair. I have replaced the chain guard housing, drive sproket, clutch shifter lever, shifter ratchet, various seals, 2 clutch springs, the clutch rod, and of course the chain. Once I put this all together...

Here's my problem: once i pull in the clutch lever, there is no action. its super spongy, and provides no resistance to indicate its building pressure.

I tried to bleed the system various methods, several times each. Replaced the piston set in the master cylinder, replaced the slave cylinder, replaced the clutch hose, all to no affect.

What the hell is wrong !!??

After reading this thread, I went home, and attempted to bleed the system via the banjo bolts.

5 months of fretting over this bike for a 2 min bleed job!

WAY TO GO VFRWORLD! I love you guys so much! I am most greatful! I will post pictures of my bike and its restoration if anyone would like to see it. and of course be willing to help anyone if i can.

What about those 2 broken bolt holes you ask?? well, I'm an automotive engineer, so seeing a poor design via honda, I improved it, and eliminated the use of those two bolt locations all together. I have also improved the response time of my clutch, and made it a lot easier to work on the sproket area if the situation ever arises again. Above all, the area is now safer with regard to the slapping of another chain breakage upon your left leg... god forbid it ever happens again.

Again, Thank you for helping me see. What a wonderful site.
Sincere grattitude,
Craig

 

I have had this problem a number of times, tilt the master cylinder up 9lean bike to right for example. You could also cap it ,unbolt it and tip it up (end of lever upo). Air gets trapped in the slight down angle / banjo area that you need to get out.

 

ok maybe i just suck at using a vacuum pump, or god forbid mine isnt working right, but i need to pick somebodys brain on the subject of bleeding a clutch.

so where im at, is that ive tied off the clutch lever with a shop rag (to ensure that the system will flow fluid down out from the master cylinder through the line and down to the slave cylinder....ive got a hand vacuum pump (one of the more popular mightyvac models) with the reservoir between the inlet line and the hand pump itself, and i put the inlet line on the bleeder valve on the slave cylinder, pump the vacuum pump like 10-15 times, then open the bleeder valve to allow the built up vacuum to pull fluid down through the line from the master cylinder and out the bleeder valve (at least thats what id *assume* is supposed to happen). the problems im having are that first, while im pumping the vac pump, i can see air seeping into the line....i guess this means that im not tight enough on the bleeder valve? second, when i open the bleeder valve, hardly anything comes out. i HAVE though noticed a definite drop in the level of fluid in the master cylinder (which i also have uncapped at this point).

am i doing something wrong, or what is goin on here? any input would be appreciated at this point...

 

Hi! I'm having the same problem with my clutch. Can you tell me where's this "banjo bolt"s and master and slave cylinder are?
Thx!

 

the clutch master cylinder is the small box-like part that the clutch lever attaches to. there are 2 banjo bolts in the clutch system...one of which is on the right side (the side opposite the clutch lever) of the clutch master cylinder. the other banjo bolt is on the other end of the clutch line at the slave cylinder end. the easiest way to find the slave cylinder is to follow the line down from the master cylinder to the next banjo bolt you see. youll know yer in the right place when you see the bleeder valve (same kind as you have on the brakes on yer car) near the banjo bolt.

unfortunately, finding the parts for the clutch system is the easy part.....bleeding this system is turning out to be a serious PITA.

 

Ok, thank you very much!
Will look at it better after work and report!

Thx again!
Regards.

 

Didn't have the time to do it. Tomorrow, now doubt.
Regards.

 

Ok, Removing the air from the "Banjo Bolts" worked for me. Although the first time, i went for a ride for testing purposes and it started to loose pressure again. Had to refill and tighten the screws a little harder, seems good now..
OffTopic: My Rectifier/Regulator seems to have stopped working, again... A friend of mine told me about a electronic substitute he bought for his CBR1000. It's much cheaper than the original and it has fame of more durability. Have you heard about this RR's?

Best Regards and THX!!!

 

yea wolf, welcome to one of the biggest problems that plagues these old viffers. plenty of people have gone back and forth with this issue, and when my bike recently fell prey to these problems, i started doing excessive research and found a few longer term solutions than just throwing a new R/R at the bike. below is the howto thread i ended up writing to bring all my research together:

http://vfrworld.com/forums/modifications/17895-charging-system-upgrade-explained.html

pretty much all the mods in that thread can benefit any bike out there, but as far as my 87 vfr 700, i can safely say that my R/R doesnt get excessively hot, and how that i have a dry cell battery in my bike, it cranks every time without issue.

good luck dude, and ride safe!

 

Chris, not sure if you got your bleeding to work yet or not, but here is my suggestion.

First, do not tie off the lever. The system will flow fluid just fine with the lever in the normal position. I suspect that may have something to do with your not getting much fluid. I'm honestly surprised you're getting any since after the piston is pushed slightly, the piston's seal takes over and there should be no path between the pressure side (where your pump is) and the reservoir side.

Second, the air you're seeing at the bleed line is likely seeping in at the bleeder threads. This is always my problem with vacuum bleeding. It usually still works, but it always bugs me because you never really see pristine clear fluid. The only time I've not seen this happen is when I installed some "SpeedBleeders" on a car I used to have. They had pre-applied thread sealant so there was no air leak at the threads.

I hope that helps.

 

Glad I found this post. I was having a helluva time bleeding mine. Once I bled the hose fittings, it was all good.

 

just got an 87 vf700 super magna. and it needs some work. first problem is i lost my clutch so this weekend im goona try and bleed. Hope i dont have the problems the rest of you seem to have had, but im pretty sure i will. bike is pretty rough and has been sitting for about 4 years. wish me luck.

 

ok I know this is an old thread, but here is the deal.
when bleading the clutch, after you get the air out of the line, loosen the bolts on the clutch slave so that it is about 1/4" - 3/8" from the engine case.
pump up the lever to build some pressure and retighten the bolts.
good as new.
what happens is if you dont seperate the clutch slave from the engine case it will take a week of pumping to build up the pressue.
so by having a space and pumping the lever up, when you retighten the bolts it forces the fluid back into the reservoir and build pressure in the system.

 

Thanks everyone especially you 02 vfr rider. I loosened the slave like you suggested, didnt do much goood then i went back and repled the banjo at the master cylinder, then loosened the slave pumped it up and tightened down. Works beautiful now. thanks again.

 

Some of what is already posted here I think might apply but I wanted to chime in, in case I'm overlooking something obvious. I got my bike from a person who had it sitting in a garage unridden for years, and after getting it in running order I noticed the clutch beginning to slip. I've changed the plates and springs with a Barnett clutch kit, and flushed all the old fluid out, being careful never to completely empty the master cylinder. I've got plenty of pressure at the lever, but it still slips pretty bad, especially when cold. Is this likely a problem with air still in the lines? Because all I did when flushing the system was multiple cracks of the bleeder valve at the slave cylinder. Is it possible that through this process, I've only made matters worse by accidentally introducing air into the system? I'm perplexed because of the firm feel at the lever, it doesn't feel spongy like a brake lever would when the system is full of air.

 

You all saved my day!!! I'd been working off and on for several weeks to get my clutch working again. It turned out to be air trapped in the banjo bolts just like many of you suggested.

Thanks everyone!!!

 

ok, the only thing that worked for me was to use a syringe to push the brake fluid backwards (from bleeder screw to reservoir) and voila!!!
That was the only thing that got me pressure on the clutch lever. Now what I want it to get more pressure on the clutch lever as the clutch is barely engaging when the lever is pressed fully. How do I do that?
thanks