Clutch Won't Engage, Bike won't move, Clutch Slave Bad?

[94szki]

Hi,

It took me 2 years, (I worked on this project whenever i had time) but I finally restored my entire front end. Took everything apart, powdercoated what I could, replaced main bearings, and rebuilt the entire front end. Got rid of those buckhorns, and replaced with an aftermarket bar. I'll attach photos here shortly. After 2 years of the bike being on jack stands, I'm finally getting ready to go for a spin!

We've gotten to actually running the bike reliably. It has had some hiccups, but it's smoothing out. Things I've done so far.

1. New battery installed (old battery was toast)
2. Clutch and Brake reservoirs totally rebuilt, air removed from system and bled properly
3. New EBC front brake pads
4. Gumout/Fuel injector/carb cleaner + 93 octane fuel

Two years ago, I let the bike turn off itself by running out of fuel before I started to work on it. My thinking was that this would eliminate residual gas from sitting in the carbs. I don't think that happened, because the bike struggled to start, especially the forward most cylinder. After a new battery, both cylinders did eventually start but sounded awful and very sputtery. I went last night and got some 93 octane and a fuel additive from advanced auto, and after running the bike for half an hour it sounds a hell of a lot better - in fact to the ear it now sounds normal again.

I was able to ride the bike around the neighborhood in second gear (this was actually before I added the fuel cleaner) but it cut off as soon as I sat on the slight incline of the driveway. I pushed it up and got it into the garage and added the fuel cleaner and topped off with a gallon of 93 as I mentioned above.

Here's where we are.

I haven't replaced the spark plugs yet, but they cost 3 dollars each so naturally I will do so for good maintenance. Because they are currently working, I didn't bother to replace them yet - I just wanted to get the bike running reliably.

I went to ride the bike around the neighborhood again after it was running for 30 minutes in the garage and it sounded healthy, but now I can't get the bike to move or propel itself. It engages into gear properly (or feels like it has) and the clutch lever feels excellent. I'm 100 percent certain there is no air in the clutch lines, I bled the line recently, and bled it again, and again, and again to be certain. Foot controls feel fine and normal too when getting into gear. When i put it in first and try to get going, the engine RPMs rise as I turn the throttle but nothing is engaging. My friend suggested I change the oil again, so I've ordered a new K&N filter and will do that tonight. I don't believe I've driven more than 2 miles on the oil that's currently in the bike - such a shame to just throw it away, but it actually has sat inside the engine for 2 years. I last did an oil change right before i started to work on the bike and it did sit on jack stands (perfectly straight) for 2 years with that oil in the crankcase. I don't know if the filter could have been salvaged, but I just ordered a new one anyway. That too has about 2 miles on it, maybe less than that.

Sorry for the long post, just wanted to provide as many details as possible. I did a quick google search and on other suzuki's i found a post suggesting some gear needs to be removed and cleaned. Another post suggested changing the oil as the oil lubricates both the clutch and the engine? If this is also true for the vs800, how could my oil be the culprit since it's brand new? I used the mobile 1 full synthetic race oil. I don't mind to change it, I just want to understand how the mechanics work. If i were to remove the slave cylinder, I'm assuming I would have to remove the bango bolt to free it from the line, and that would necessitate a full clutch bleed again? Could the clutch slave cylinder be the culprit?

Has anyone had this issue before? It feels like everything is running fine, but the transmission is not engaging with the engine. Radiator and fan are working fine, when the bike was idling in the garage for half an hour the fan was periodically coming on and off. Sounded to be running normal again. Anyone know if I can remove the spark plugs with a swivel socket 'without' removing the fuel tank again?

Things to do:

1. Oil change + Oil filter change
2. Final drive/gear oil change
3. Radiator fluid change
4. Spark plug change
5. Carb adjustment (i will put this one off, but probably need it)

Thanks!

[Lechy]

Did you remove, dismantle and clean the slave cylinder? They do tend to get badly crudded up inside which could cause the piston to get stuck and to not return.
As for the plugs, remove the chrome covers to give better access.

[emoji41]

[94szki]

Hi lechy,

Thanks for your reply! No I didn't remove the slave before I bled out the air and filled up the reservoir! I didn't think about removing it and cleaning it because I didn't know any better. This is my first time working on a bike.

If i were to remove the clutch slave now, it would require a full fluid bleed again right? Can i remove the slave with the bango and metal line attached or do they have to come apart? I'm assuming they have to come apart; and there goes all my fluid again...

Thanks for the help, I appreciate it. What do you think?

[Lechy]

Unbolt the slave, 2 bolts 10 mm wrench if my memory is still good. it may take a bit of wiggling to pull it from its seat. Once you have it hanging, put a tray down to catch the fluid, gently pump the lever to push out the collar and piston. You may be able to remove the piston and clean it but I'm not sure if there will be enough room. I fitted a stainless braided line years ago. It doesn't take much fluid to do a full bleed, but it can be a ball ache getting the fluid moving through the system, if you have problems, I'll explain a couple of ways to get you sorted later.
[emoji41]

[hillsy]

While you have the slave off, check that the bike goes into gear and the drive train is solid.

[94szki]

When I take the slave off, with the banjo line and the rest of the system still in tact, I understand I can ease the lever in hopes of pushing out the piston under hydraulic pressure. I don’t have a new seal kit though. Do you think that the crud (if any) is in the recess of the piston cup ? I hope I can push the spring and piston cup back into the housing if I pop it out.

Now on the bikes side, do I need to fiddle with the push rod at all? Is it free floating there or is it screwed into something? Of course I’ll wipe away any crud that may be on the pushrod gasket/sleeve, but I’m not sure to what extent I need to fiddle with that side of the slave?

In theory, maybe my piston is stuck in the pushed out position now which is the source of the issue ?

Thank you all for responding I appreciate it !

[hillsy]

In theory, maybe my piston is stuck in the pushed out position now which is the source of the issue ?

That's what we're thinking.

[Lechy]

Get yourself a small C-clamp to push the piston and spring back in. also helpful when messing with the front brake calliper. The O-ring seal should be OK just pull it off and clean the ring and groove.The push rod is free floating and will remain in place.

[emoji41]

[94szki]

I do have a small C-clamp, thanks! I will hopefully give this a shot tonight after work if I'm still in the mood.

I will only use brake fluid to clean the parts, will try to do this without a new gasket kit.

So how do the mechanics of this work? The hydraulic system pushes the slave, which in turn pushes the pushrod from left to right?

So to check to see if the clutch is fine (with the system disassembled) I can theoretically push the pushrod in from left to right and then engage the footpeg with my hand and put the bike in first? I wonder how much force is needed to move the pushrod.

Does it need to wiggle back and fourth and have some play in it? What should i expect it to look like?

In this videoclip at 35 seconds the pushrod can be seen. It looks like there is some type of plunger/gasket around it. Do I need to mess with that at all?



Thank you everyone!

[Lechy]

You won't be able to push the rod. Pull the slave, put the machine in 1st try to push it forward. If the bike does not move, the clutch is fine, if it moves, you will have to dig deeper for the problem. There are no gaskets to worry about. The push rod passes through that orange oil seal. The guy in the video was asking for a paint job by removing the master cover without covering the paintwork with rags or better still plastic bin liners. If the clutch slave is working OK and you operate the lever without covering the master there will be a return jet of fluid about 1/2 meter high.
Brake/clutch fluid eats paintwork.
[emoji41]

[94szki]

Hi guys,

I did work on this issue last friday, and have some interesting/confusing results.

Pulled the slave, it was crystal clean inside - absolutely no gunk. Very simply design, one gasket around the piston, and a spring behind the piston. I wiped them down and then lubricated them with brake fluid and put them back together. You have enough room to work on the slave without unbolting the banjo bolt.

To cut to the punchline, I think my problem may be a bad spring inside the slave? The bike will shift gears perfectly fine when you first turn it on and its still relatively cold. Once the engine heats up (i.e. when I leave the bike idling for 30 minutes) it simply won't shift. Could it be that the increase in engine temperature if affecting the return/rebound of that spring? I had my bike idling as I waited for my friend to arrive. We were going to go for a ride. When i got all my gear on and went to move the bike, it decided it didn't want to go for a ride and rather hang out in the garage...

I could buy the rebuild kit (if i can find one on ebay) and replace the gasket and spring for the slave. Then bleed it once more. They also sell new slaves for about $80 bucks on ebay, but given it's simplicity I just cant figure out why it could be failing.

I'm having trouble finding a VS800 kit, but I found this one: Could someone verify that it would work on our bikes? (It looks like it comes with a black oil seal, but I rather leave the orange one that's in the bike)

https://www.ebay.com/itm/Suzuki-Clutch- ... 1#viTabs_0

When the engine is fully warmed up, it cant shift - but when the engine is cold it works perfectly. I bought new oil, but I haven't gotten around to completing the oil change yet.

I have excellent lever pressure and I don't believe there is any air in the system. With the fluid cap off, I pump the lever by hand 15-20 times to give it good pressure, and then I hold it compressed with my left hand. I then open the bleed valve with my right hand and watch the fluid come out of the bleed valve (through a small clear line to a catch bottle) with no bubbles. I then tighten up the bleed valve and only after its tight i let go of my left hand. I repeat this process 15-20 times. I don't understand how the fluid would shoot up out of the top of the reservoir - unless that's the job of the return spring to push the piston back out with such abrupt force. If that's supposed to work that way, it's clearly not happening here.

Any ideas?

[Lechy]

You got a real Gremlin in the system. When the bike is cold, can you ride it?
Looking at the E-Bay kit, it does not seem to be compatible with the 800's.
It's the clutch springs returning the plates to engaged position which causes the fluid spout, not the spring in the slave.
Who rebuilt the master? It is possible that the main plunger seal is in the wrong way around, but this shouldn't cause your problem.
It would appear that the clutch fluid is not returning to the master causing a pressure build up in the line when the fluid gets hot and expands. This is usually caused by a blocked return hole in the bottom of the master cylinder or the hose has begun to deteriorate internally causing a blockage.

[emoji41]

[94szki]

Hi thanks for the reply!

I rebuilt both the left and right reservoirs months and months ago.

Yes I can ride the bike just fine when its cold/just started.

I will try to fish a little strand of wire through the tiny return port within the bottom of the master cylinder. If this fixes my issue, I wonder if this will keep on happening to me every once in a while. Maybe the hoses need to be changed one day. I wonder if I can blow some compressed air through that tiny return hole to 'power' flush it clean.

I'm running Mobile 1 10W-40 Full Synethetic. It says it's optimized for wet clutch performance. So I think I should be ok with the oil?

I read a post online about lubricating the shifter. This might be totally unrelated to my present issue, but was just curious how you are supposed to do that.

I hope the little wire strand will go deep enough in the line to unclog it. Im going to give it a try with fluid in the reservoir. I haven't seen any fragments or flakes show up when I bleed out the system from the bottom, so I'm hoping the lines are still good.

[navigator]

You got a real Gremlin in the system. When the bike is cold, can you ride it?
Looking at the E-Bay kit, it does not seem to be compatible with the 800's.
It's the clutch springs returning the plates to engaged position which causes the fluid spout, not the spring in the slave.
Who rebuilt the master? It is possible that the main plunger seal is in the wrong way around, but this shouldn't cause your problem.
It would appear that the clutch fluid is not returning to the master causing a pressure build up in the line when the fluid gets hot and expands. This is usually caused by a blocked return hole in the bottom of the master cylinder or the hose has begun to deteriorate internally causing a blockage.

[emoji41]

IMO Lechy is right on.
The OEM rubber piston seal is about $5, the rest does not need to be replaced. If your seal is not scored, you are all set.
The fact that you do not get a guyser when you pull the lever is KEY.
The small hole is plugged and slowly builds pressure, holding the clutch disengaged.
Rebuild the master again, Do not try to clear it with compressed air, unless it is totally disassembled on the bench. Pass a wire through the small hole. that is the problems source.

[navigator]

I read a post online about lubricating the shifter. This might be totally unrelated to my present issue, but was just curious how you are supposed to do that.

I hope the little wire strand will go deep enough in the line to unclog it. Im going to give it a try with fluid in the reservoir. I haven't seen any fragments or flakes show up when I bleed out the system from the bottom, so I'm hoping the lines are still good.

The shifter lube problem was related to the 1400 and is not applicable to the 800.

[94szki]

I don't get a guyser or anything when I pull the handle with the cap off. The bike however shifts perfectly when cold and has solid lever pressure.

This morning before work I took the fluid cap off to see how large the return hole is --- and boy is it microscopic! The only thing I found that would fit inside was a wire strand from a metal brush.

Do you think it would work if I tried to stick something inside it to unclog it? If so, what wire strand has worked for you guys and how much travel/depth is it supposed to have? When I stuck the wire strand from the metal brush in it, it didn't go far into it at all.

I'm trying to avoid rebuilding the master if I don't have to. If it comes down to that of course I will do that too.

Would a reverse bleed potentially work? Pumping the brake fluid from the bleeder valve on the slave all the way up back into the reservoir? Would i need to hold the hand lever (compressed/piston pushed in) in order for fluid to come back in from the bleed value, or is it supposed to come back through that tiny hole? They sell those little oiler hand pumps at Auto Zone for $15 bucks. I can hook a hose to one and the other end to the bleed valve. What do you think?

Thanks for the help guys I appreciate it !

[navigator]

A wire plucked from a wire brush is perfect.
The passage is less than 1/4" wall. The wire will pass until it hits the piston. The piston has various grooves cut in it, so depending on it's location, the wire will go deeper in the hole.
Those oiler hand pumps is what I use to reverse bleed. You do not need to hold the lever to push fluid up through from the bottom. BE CAREFUL...pumping fluid from the bottom will shoot several feet in the air from the small hole with no cover on.
Start by removing some fluid from the master with a meat baster, then hook up your pump to the bleeder, replace the cap, and see if it fills from the bottom.

[hillsy]

I always reverse bleed both brakes and clutches. I use a 20 or 30cc syringe and a 6" length of clear hose. It's best to remove the bleed nipple and wrap the threads with plumbers tape before you start so you won't get any deceptive air bubbles in your syringe. You can push the fluid up the line, then draw it back down as many times as you like until you are certain there's no air in there.

[94szki]

Ok, here are the weekend updates.

1. Plucked through the return hole as best I could. Honestly didn't go that deep. But I do see bubbles when bleeding.
2. Unscrewed bleed valve on slave, added teflon tape.
3. Used air compressor with air nozzle to push air up from slave to reservoir.
4. A misty substance came into the master cylinder. I don't know why I expecting it to come in fluid like - it came up as if you were shooting a spray bottle. It didn't blast fluid out of there, it just filled the reservoir with mist.
5. Since there was so much air in the line now I started to bleed the system again.
6. Took a while but got the air out, using a vacuum hand pump at the slave to get it going.
7. Wasted half a bottle of fluid bleeding, was pretty sure all the air came out.
8. Clutch worked again, worked great in garage. Went for a ride - after 30 minutes (I guess after it got hot) it left me stranded.
9. Moved bike to a sidewalk, let it cool for 15 minutes (tried to look cool sitting on the sidewalk - but felt like an idiot). After 15 minutes, clutch barely started working again - got the bike back home. I knew it would do this, so I only rode around the neighborhoods - at least i wasn't far away.

When I left the garage (before I left for the ride,) the fluid level was a bit over the halfway mark of the inspection window. When I get back, the inspection window looked like its totally full. I understand fluid expands with heat - but just providing more information. I tighted down the gasket and screws on the lid very well. So i know there is no leakage. Maybe I tightened them down so much that the air has no where to escape? But it should escape from that little hole on the lid right?

Thoughts:

1.Either there is still air in the line --- somewhere.....
2.Slave/spring is bad - contemplating buying a new unit just for piece of mind on a 1994.
3.MC piston is bad, or return hole is still plugged somehow?...

*When bleeding, I typically open and close the lever slowly - that's why I wasn't getting the large 2 feet fluid launches as you guys mentioned.
*To test this, I pulled in the lever and let it slam back open a few times as I was bleeding, and yes I did get some large fluid launches from time to time.
*I noticed when the lever has solid pressure, you don't typically get these launches, but just a small bubble on top of the return hole.
*I typically have a lot of fluid in the reservoir. It's probably 3/5 full. I think you only get the drastic launches when the fluid is on the low side.

Because the fluid seems to expand, could I possibly have too much fluid in there? I can't imagine I should go below the halfway mark?

Bleeding method:

1. Connected vacuum bleeder with 1/4 clear line and half a roll of electrical tape around its lid. (only way to hold pressure)
2. Built pressure on hand pump to 25
3. Pumped lever 30 times until solid feel, and kept it held in.
4. Cracked bleed valve, gave it 3 seconds.
5. Tightened up the bleed valve.
6. Let go of handle.
7. Repeat (3000 times until you have popeye wrists )

I tried to reverse bleed using the oiler pump, but I could not get it to go up through the line. My assumption is that the oiler isn't air tight at the thumb pump and the pressure just escapes. For anyone trying to use the oiler to pump up (reverse style,) I went and picked up a 1/4 inlet clear fuel filter from the store ($3.00) and this worked perfectly at preventing the powdercoat/paint of the oiler from getting into the line that goes into the bleed valve on the slave. It however did not work. The oiler was good for gracefully re-filling the reservoir though. Much less messy than using the bottle to refill - unless you are an expert at the wine pour (tilt and swift twist to stop pouring).

I have tried every method of bleeding... except for the syringe. I'm trying to avoid another $40.00 bucks on a tool - but it's whatever at this point. I'm assuming the syringe SHOULD be air tight, so it might work to get the air out. The vacuum hand pump I got was NOT air tight in any way! I had to use half a roll of electrical tape around the cap to get it to hold pressure.

Please review this product and let me know if it should work. Is the capacity ok?

Lumax Fluid Exractor LX-1386

Ok, so for reference I have also found these old posts:

Designers bleeding instructions
Similar clutch bleeding thread

I have aftermarket handlebars now and my clutch banjo (attached to the resevoir) is inverted in an odd way. The cable itself does like an upsidedown loop at the top (where it connects to the handlebars) since the bars are shorter. It makes sense that there still could be air in the line at that point. I'm hoping the syringe might work.

Please read my thesis and let me know what you guys think.



Thank you for continued patience and help VS800 gods.

Does anyone live in VA?

[94szki]

Long overdue update on this.

1. Replaced the clutch slave cylinder with a new unit. (That didn't fix the problem.)
2. Tried to reverse bleed, but couldn't push fluid up into the master.
3. Cursed and moaned and finally got around to taking the master cylinder off the handle bars.
4. Disassembled the master and cleaned it. Did not find any obstruction in the small return hole.
5. Compared the original piston and spring to the aftermarket replacements.
6. Decided to clean and re-use the ORIGINAL piston and spring instead of the $40.00 replacement parts.
7. Added a few rounds of teflon tape around the bleed valve prior to bleeding system.
8. Successfully was able to reverse bleed fluid from the slave cylinder all the way into the master on the handlebars!
9. Conventionally bled the system from the top down a few times after reverse bleeding.
10. Clutch is holding pressure and seems to be working well.
11. Clutch grabs instantly now - before it had about half lever take up before it engaged. I'm thinking the new spring in the new slave cylinder unit did something after all.
12. Ran the bike (with stop watch) for 1 hour and 22 minutes post bleeding. (Included spirited driving).
13. Bike continued to run and clutch did not stop working.

Overall, I can't narrow it down. Somehow the small fluid return hole was clogged (as everyone mentioned) however when I removed the replacement piston and spring I did not find ANY obstructions in the bore. Maybe the aftermarket/replacement piston ITSELF was the issue?

I plan on continuing to ride around this week after work to make sure the bike is fully fixed. Now if I could only figure out how to ground the horn - that's the last thing that I need to fix. I posted a new thread on that.

Thanks!
Emmanuel