• 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 The previous version was outdated and no longer supported.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!

front brake master cylinder failure?

Travis Shrey

Travis Shrey

Husqvarna
A Class
Anyone have an internal failure on the front master cylinder? Twice in the last two days I grabbed a handfull of front brake and the damn lever went all the way to the grip. Next pull it was fine. There is no leak anywhere, plenty of fluid in the system. The only thing I can think of is that there must be a small tear in the seal around the piston.
 
Yep, same thing on mine. Rebuilt kits specifically for the Husky weren't readily available so you have to source from another. You have to buy a whole new unit from Husky for big bucks or source the parts. I ended up buying a used KTM 450 Brembo master which is identical for $30 on ebay. Works great now.

First I would try bleeding the lines and fresh fluid though.
 
warranty depends on the year I guess. My 06 I think was 6 months. Newer ones may be longer but unless you just bought your bike brand new my guess is that it is out of warranty.
 
So I did the rebuild kit on the master cylinder, bled the system with fresh fluid and it does the same damn thing. I didn't check the bore of the master cylinder, I guess something could have scored that. It feels like a small bubble in the system, but it isn't always there. I took the whole system off the bike , tapped the caliper while moving it in a lot of orientations and then hung the whole system up by the lever. If any bubble got dislodged it should make its way up to the master cylinder. I'm pretty perplexed by this.
 
I got rid of the Mickey Mouse contraption mounted on a Mechano brace when my 630 was still new and replaced it with a Magura square fluid reserve like for the clutch (but larger). I´d have broken off the OEM setup in no time.
 
Travis Shrey said:
Do you have an SMS? On a TE I have a square Brembo reservoir like the cluch side.
Click to expand...

Took a couple times to get mine properly bleed too even with the new KTM unit. Might also be your caliper seals too if you continue to have problem, or possibly a bent rotor.
 
I might be worth looking at the other end of the system...
Are your wheel bearings good? It could be a simple case of pad knockback.
 
I don't know what pad knockback is, but I don't think it has anything to do with the wheel. Even sitting at a stop if I keep pulling and releasing the lever most pulls are firm and then every once in a while it will pull twice the distance and never get really firm.

If the caliper seals are leaking wouldn't I see fluid coming out of the caliper? I figured the master cylinder could fail in a way that it wouldn't leak by pressure getting around the first seal but being contained by the second. I'm about ready to buy a whole new master cylinder off ebay.
 
If everything else is right then it sounds like the high pressure seals or the bore in the master (possibly at the reservoir port) have a slight imperfection acting intermittently.

Pad knock back is just the pistons being forced back into the calipers further than normal by a bent disk or stuffed wheel bearings. You're right about the calipers.
 
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