Clutch Gremlin

sixpack577

Top Gun
Donating Member
Registered
2008 Suzuki B-King, 6k miles.
Only had time to put around 500 miles on it since I got it in November.
Most every mile was cold weather commuting.
I do not know the bike's history, otherwise it looks and did run excellent.
I have not once popped, slipped, or abused the clutch.
Other than the throttle being pinned, I've been easy on the bike. I ride easy on cold roads.
The clutch worked perfectly. I started riding it to work a few miles lately(no time to really ride).
Suddenly the clutch slipped a couple times. Easing up through the rpm's, and once the bike started making power past 6k or so, it started to slip.
The next day I went out for a cruise to see if it would do it again...I didn't think I was going to make it home.
I thought it was kind of strange for the clutch to have worked so well, then just suddenly die, but it happens.
Not having the cash to buy a new clutch at the moment I left it alone.
Rather than remove the clutch I decided to remove the pushrod and make sure it wasn't gummed up and sticking.
It had some crud from the chain on it, but not what I'de think would cause it to stick and/or drag.
While it was apart the cylinder popped out of the housing on the sprocket cover.
No big deal, I just had to bleed the clutch now. Problem is, it will not bleed! No lever pressure, at all.
I removed the cylinder again, and filled the housing over half full.
I then put it back on, using the 2 bolts to slowly draw it on. Instant lever pressure! But off course there will be air.
I then hold the lever, crack the bleeder, and as expected, a big air pocket in the bleeder hose I have on it. Great! But now again, no lever pressure, at all. I repeatedly pump the lever, crack the bleeder, and nothing. It will not build pressure.
I then pump the lever and clamp it to the bar. I put a syringe on the end of the bleeder hose and open the bleeder, then use the syringe to pull air and fluid.
This is working great, or so I though. As plenty of air and fluid came out, only the level in the master cylinder never dropped, at all. This is after multiple attempts too, over a dozen.
Enough fluid came out to easily have filled the line, and the cylinder was already full or close to it.
I assume it's pulling air from around the threads of the bleeder.
Every part of the master cylinder, line, and lower cylinder is bone dry. The seal on the piston does not leak.
Every part appears as brand new, even the threads on the bleeder and cylinder.
The strange part is that the clutch worked fine, aside from slipping. The lever had plenty of pressure and would spring back instantly. There were no engagement issues. You could pull the lever and easily engage first gear, there were also no shifting problems at all. None. Not even when limping home.
I have bled many clutches and countless brakes over the years, and I understand that some can be a pain, but I have never seen this before.
The master cylinder was working fine, and as said, when you fill the pushrod cylinder the first time there is plenty of lever pressure...until you bleed it once.
Without ANY leaks, or traces of brake fluid I cannot understand why it will not work, as it's a simple system.
The fluid in the master cylinder not going down has me wondering, but for it to suddenly go bad while it's apart seems unlikely to me(although it's possible).
I have yet to remove the clutch to inspect it, but at this point that's irrelavent. If the clutch is new or fried , it doesn't matter if it can't be engaged.
It's been a busy past week or so for me and my mind has been elsewhere. So I'm taking a step back and trying to find the simple problem staring me in the face.
Someone's about to buy a B-King really cheap, seriously.
I'm out of ideas at the moment.
 
Hope you get this figured out man. Weren't you having electrical gremlins too? Hope you didn't get a lemon. :down:
 
Hope you get this figured out man. Weren't you having electrical gremlins too? Hope you didn't get a lemon. :down:

No electrical problems at all.
But an oil leak.
My right foot was covered in oil, I figured the valve cover. It was, fixed it, easy.
Then I could notice the head was leaking oil from the bottom side of the head gasket, a very small stream. Never oil in the anti-freeze, or anti-freeze in the oil. No smell of anti-freeze, at all.
You cannot torque the head bolts on a B-King in the frame either. As you cannot get a socket and extension straight down on the 4 corner bolts. The B-King frame is too tight. U-joints/swivels would be needed to even try to get on the bolts, then of you'de never get proper torque. It's out with the engine or nothing.
So I rode it, parked it, several times. Same very small oil stream(like it was going to majically go away).
It set for a couple months. Cranked it, rode it, no leak. For 5 days.
Then, 2 inches to the right of where the oil stream had been, very small oil bubbles like a pinhole in a tire(and still from the bottom side of the head gasket). This is on the right edge of the block where the head gasket visibly sticks out.
That happened once and once only.
I then ordered a head gasket and the engine/frame sockets.
That fixed the leak, I didn't even have to touch it:laugh:seriously.
Several hundred miles later, still no leaks.
Ever seen a head gasket fix itself? Me neither.
In all my years of wrenching I have never seen a bike like this one.
As I said...Gremlin:laugh:
WTF?!:banghead:
I love the B-King...I'm just over this one.
I told a guy to bring me $4500 and take it away, if he(or anyone else)shows up, it's gone.
 
It almost sounds like a restiction in the line somewhere. Maybe take it off a blow compressed air thru it.See if its kinked or blocked.

I've had success just flicking the lever at the end,about a half in. pull at a time.Couple hundred flicks.:whistle: Get the air to bubble out at the master.I've also opened the bleed screw and gone to bed.Check it in the morning.Gravity should have emptied it.

I'd probably blow those lines to start with,the flexible one,and the hard line (if there is one).

Good luck dude.

RSD.
 
Slippage does not normally indicate a problem with the Master Cylinder, slave or lines although you have problems with them now.
Look to the clutch itself, springs, plates, etc. My guess is its your springs but you may have worn friction material, wrong oil, etc.
 
When all this started was the master cylinder fluid level OK.
Problem sounds like the system was part pressurised all the time.
Did you change levers or anything as i've noticed the pivot point on some isn't 100% and effectively that applies a bit of pressure as if pulling the lever a little.

When is started to slip did the lever feel normal?
If it did then its unlikely to have been hydraulic fluid related....good call on trying the pushrod.
Have you tried bleeding the system from the bottom bleed nipple...when i had my old B-king i once bleed the system and had to do it with the master and slave cylinders unbolted and just syringe the fluid through by pulling it from the master down to the slave and get someone to keep topping up the reservoir as you focus on the syringe.
 
I usually do the opposite, buy injecting clean fluid at the bleeder and filling up the master cyl.

Then I break the line loose at the master and snug it lightly. Wrap the line with a rag, and pump the master up, and break the line loose at the master I do this a couple times, and then bleed like normal.
 
I usually do the opposite, buy injecting clean fluid at the bleeder and filling up the master cyl.

Then I break the line loose at the master and snug it lightly. Wrap the line with a rag, and pump the master up, and break the line loose at the master I do this a couple times, and then bleed like normal.

I tried that too.
When I tried pushing fluid up through the bleeder with the syringe it pushed it out around the bleeder screw threads, even with it just barely broken loose.
The bleeder and housing threads look brand new.
No leaks or signs of previous leaks either.
 
I would look and see if the pressure plate is moving back and forth correctly. If its hanging out for whatever reason the master cylinder would have pressure once and then be all the way out with no force being applied by the plate
 
When all this started was the master cylinder fluid level OK.
Problem sounds like the system was part pressurised all the time.
Did you change levers or anything as i've noticed the pivot point on some isn't 100% and effectively that applies a bit of pressure as if pulling the lever a little.

When is started to slip did the lever feel normal?
If it did then its unlikely to have been hydraulic fluid related....good call on trying the pushrod.
Have you tried bleeding the system from the bottom bleed nipple...when i had my old B-king i once bleed the system and had to do it with the master and slave cylinders unbolted and just syringe the fluid through by pulling it from the master down to the slave and get someone to keep topping up the reservoir as you focus on the syringe.

Yep, everything worked as normal.
Then the clutch slipped a little when just cruising and the rpms started climbing past 6 or 7k.
Only slipped a couple times. I went out for a test ride the next day and didn't think I was going to make it home.
The clutch was slipping badly in every gear, even with the slightest throttle.
I had to crawl up to the speed limit.
I though it was strange for the clutch to go away so quick, after 500 or so miles of it working perfectly. But not knowing the bike's history, I just chalked it up as one of those things.
I could shift gears, and shift into first at a stop without any problem.
The lever still had plenty of pressure. At that point it definitely wasn't a hydraulic problem.
I want to say it's the master cylinder, but with no leaks and no lever issues(I tried pumping the mc with the lever off too), it seems strange for it to just die when the system was opened. But that happens too.
When I tried pulling fluid down with the syringe on the bleeder the mc level wouldn't go down at all. It must have been pulling fluid from the line and from behind the piston in the slave.
The bike did sit at the dealer for over a year, and one of the techs said it had only been ridden a couple times. It is an 08 with only 6k miles too. Seals do dry up, I would just think that a bad seal in a mc would leak.
I hate to throw money at a problem, but it's looking like ordering a mc rebuild kit when I buy the complete clutch(bike budget is currently empty).
 
I would look and see if the pressure plate is moving back and forth correctly. If its hanging out for whatever reason the master cylinder would have pressure once and then be all the way out with no force being applied by the plate

I need to take the clutch cover off and dig a little deeper.:beerchug:
 
It almost sounds like a restiction in the line somewhere. Maybe take it off a blow compressed air thru it.See if its kinked or blocked.

I've had success just flicking the lever at the end,about a half in. pull at a time.Couple hundred flicks.:whistle: Get the air to bubble out at the master.I've also opened the bleed screw and gone to bed.Check it in the morning.Gravity should have emptied it.

I'd probably blow those lines to start with,the flexible one,and the hard line (if there is one).

Good luck dude.

RSD.

I would think if the line was blocked I would get lever pressure.
 
I tried that too.
When I tried pushing fluid up through the bleeder with the syringe it pushed it out around the bleeder screw threads, even with it just barely broken loose.
The bleeder and housing threads look brand new.
No leaks or signs of previous leaks either.

That still kinda says to me its plugged somewhere. Why wouldn't fluid make it up to the master.

Did you pull the line yet?

RSD.
 
I finally got around to getting a rebuild kit for the clutch master cylinder.
...and it made no difference at all!
This problem defies logic, it makes no sense at all.
I do not know what else to do with it, I cannot remember at time working on anything to where I was at a total loss.
I officially hate this bike.:banghead:
 
Have you pulled the plates off yet?

Nope, no need to.
Doesn't matter if the clutch plates are like new or fried if I can't get lever pressure to work the clutch.
The pushrod travels as it should and the piston in the slave cylinder for it has pressure against it.:beerchug:
 
I suggest you remove the clutch cover and check to see if the pressure plate screws didn't come loose causing the clutch to slip. The master cylinder and slave release the clutch to engage into gears, not cause the clutch to slip. Inspect the clutch fibers thickness. My clutch was slipping so I replaced the clutch and that fixed it. My bike has almost 20,000 miles and almost two years old. Good luck and hope you get it fixed. A slipping clutch takes the enjoyment out of riding the bike.
 
I suggest you remove the clutch cover and check to see if the pressure plate screws didn't come loose causing the clutch to slip. The master cylinder and slave release the clutch to engage into gears, not cause the clutch to slip. Inspect the clutch fibers thickness. My clutch was slipping so I replaced the clutch and that fixed it. My bike has almost 20,000 miles and almost two years old. Good luck and hope you get it fixed. A slipping clutch takes the enjoyment out of riding the bike.

I'll get around to removing the clutch cover, but right now I don't want to drain the oil.
My bike budget is empty, and $45 for oil can wait until I'm ready to change it, and the clutch itself if need be.
If the clutch still slips I'll replace it, as it's an easy job.
The issue at hand first is for the clutch lever to work.
If I can't get lever pressure it doesn't matter what condition the clutch itself is in.
I also understand how the system works.
Since fluid will not travel out of the mc, the reverse is likely, meaning it can't flow back into it. If that is/was the case, it would mean that the pushrod operating the clutch itself would be slow to disengage, and therefore cause the clutch to slip.
Thanks anyway:beerchug:
 
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