• 4 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     TE = 4st Enduro & TC = 4st Cross

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

Diagnosing clutch failure

J

jeffchri

Husqvarna
B Class
Hey there - I just had a nice 2-day trip riding in the desert in eastern WA, on my 2008 TE510. First day we spent in the dunes and had a great time, and I didn't notice anything wrong - but when I was getting setup for the 2nd day, I suddenly had no clutch whatsoever - the lever went to the grip with no resistance.

Fortunately, a riding buddy had some mineral oil and a syringe/tubing combo and we were able to bleed the system (the resevoir was totally dry) and refill and everything appeared to work ... though there's some chance that it was getting softer throughout the day. Hard to tell.

What exactly should I be looking for? What could be leaking where? The levels were at 0, so it seems like it's not just air sneaking in somewhere ... but if there is a leak, it's slow or someplace invisible, because I never saw any seepage anywhere.

Any help appreciated!
- Jeff
 
It sounds to me that the oring in the slave cylinder needs replacing. I think older KTM (99-00) will fit as husky does not sell the part separate.
 
There's an o-ring on the piston that fails in the clutch slave. Happens just about on every one of those magura setups.

You can get a new piston fom 7602 racing, but if your slave casing is warped like mine was it won't work.
 
The first thing I would do is check the clutch line itself for any leaks. I have had 2 go bad, so it does happen. If you aren't seeing any oily areas along the line, or at the master cylinder then the slave cylinder most likely went bad. It could be as simple as your o ring going bad and in that case a new one will fix the problem for a while. The main problem with the slave cylinder is that the piston is poorly designed, and has no "skirt" to support it as it travels in and out of the cylinder bore. The piston kicks from side to side as it travels in and out in the cylinder. Over time it wears out a little notch in the cylinder, and the o ring looses contact and leaks.

We designed a new clutch piston that will work in a cylinder that has been notched out and also has a longer "skirt" to prevent it from rocking side to side. Ours is just a little bit larger than the stock, so like Gestion01 said, if your stock slave cylinder is warped you will have trouble installing our piston. Here are a couple links. The first one includes an excelent how to on straightening a warped slave cylinder.

Sorry for the long rant, its early in the morning and I've had wayyyy too much coffee already. :D

http://www.cafehusky.com/forums/showthread.php?t=5032
http://www.cafehusky.com/forums/showthread.php?t=3726
 
So*...*It*looks*like*my*problems*are*still*here.*:(

I*got*and*installed the 7602 piston and it went in in what I thought was a proper way - it didn't bind and didn't have any visible slop. I reinstalled everything, filled and bled the system and went for some short pavement test rides and all seemed to be well ...

I'm now camping (and trying to sleep but stressing) at the Desert 100 race outside of Odessa, WA ... And I'm going to have to bow out. I took the bike out for a spin in the flats for about an hour to shakedown a bit more - I had also done some rad repairs - with a lot of heavy clutching, and that too seemed well. I came back from dinner to find that the lever suddenly went to the bar, and sure enough the resevoir was empty again.*

So ... help!

Which of these makes sense as an explanation as to what is happening? And am I missing anything?

- slave cylinder itself: I guess it could be worn out of round ... Though the 7602 piston fit fine
- hose: no visible leaks but I guess it could be hiding. This last failure occurred with very little actual riding, so I guess maybe a failing hose could be getting worse rapidly?
- perch/master resevoir: maybe ... There is a thin seam-like line running the length of the bottom of the inside of the master cylinder resevoir at the perch, but it could be just a casting remnant (and that's what 2 mechanics at one of the suspension booths said). It would explain what appears to be a growing failure, though a crack there in particular seems like it'd just drain into the system
- other??? Seals at the master? Again, no visible leakage up there, though it'd be harder to see ad there IS lube at the lever joint an it could mix with that ...

I'm thinking about ordering a whole new system from Taskys ... I have a weeklong trip to Moab in two weeks, so I can't afford the time to keep dinking. Maybe try fixes in a particular order until it's solved, then return parts not used? But in what order, at this point?

Thanks in advance for y'alls continuing help!

Ps. If I replace the whole slave cylinder, will the Zip Ty Racing slave be compatible with the 7602 piston?
 
Im no expert with these, and am barley even familiar with them. However, if this was mine, I think id be looking at the slave cylinders o-ring, which should have been replaced with a X ring if you didn't already do that. Any chafing or grooves on that ring and it will not seal properly and leak into the engine.
 
Jeffchri,

When you had your slave cylinder apart to put our piston in did you notice if it had the silver half moon wear marks on the inside of the slave cylinder? If it did have the wear marks our piston should have taken care of the problem, but perhaps if they were big enough then the cylinder is just plain shot. If the cylinder didn't have the marks then the problem is almost certainly somewhere else.

Your extra x ring should be there any day now, so maybe try swaping x rings.

Our piston does work with the zipty slave cylinder.
 
There was no visible wear at all, actually. Hmm.

I ordered a whole new OEM setup of cylinder and piston, I'll give that a try as well. I need to have lots of options available, as we're leaving in, like, 12 days ... :eek:

What is the seal situation up at the master cylinder, in the perch? Surely there are seals up there that could go bad?
 
jeffchri;89587 said:
What is the seal situation up at the master cylinder, in the perch? Surely there are seals up there that could go bad?
Click to expand...

Rebuild kits are available for the master cylinder here in the UK and I imagine worldwide from Magura suppliers. *I think* the ones for Huskies are 9.5 mm diameter. The master cylinder type is 163, mineral oil. Hopefully more knowledgeable folks can confirm this. :)

0720555_L.jpg


But I would expect that losing a reservoir's worth of oil out of the master cylinder would leave a pretty obvious mess, so IMHO the first suspect still has to be the slave. Hope you catch it!
 
jeffchri;89587 said:
There was no visible wear at all, actually. Hmm.

I ordered a whole new OEM setup of cylinder and piston, I'll give that a try as well. I need to have lots of options available, as we're leaving in, like, 12 days ... :eek:

What is the seal situation up at the master cylinder, in the perch? Surely there are seals up there that could go bad?
Click to expand...

There are certainly seals up there and they do go bad. But the difference is that if they go bad, you don't get "mystery clutch fluid loss". You get either "reservoir is full but the clutch mechanism still doesn't work all the time" or "clutch fluid is leaking out of the master cylinder".

Since your fluid is going away with no visible leak, I think you must still have a slave cylinder problem despite the 7602 Racing piston.
 
Jeff, if the new x ring doesn't fix the problem, I would be happy to send you a new clutch piston if you think that might help.
 
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