Dear Mr. Know-It-All,
I have a 2017 Husky FC450, and until recently, I pretty much loved this machine. But last weekend we were up in the high desert hill-climbing and the clutch started acting funny. The feel at the lever got vague and then went away altogether. We popped off the slave cylinder on the trail and really couldn’t tell anything, other than the fluid level had dropped considerably, which we checked after yanking off the hydraulic clutch slave. One of the guys with us said we could add water and get some clutch back, then drain and clean the system when we got home. This failed, as in seconds the water, too, vanished and the clutch action was dead. We limped back in, but my question is, what happened? What should I have done?
Well, Vern, your first clue is that while the machine was running, the power was still good, yet the clutch handle went away. This means that the clutch itself was fine, and the drama erupted when a seal in the Magura slave cylinder was damaged and released fluid into the engine. Adding water to the slave cylinder is no bueno, as it, too, will find its way into the powerplant. We know that this was an issue with 2017 and some 2018 Husqvarna machines that come equipped with a Magura system as opposed to the KTM machine, which is fit with a Brembo unit. The two engines are virtually identical, with the exception of the slave cylinder. We hear that a sharp edge on the slave piston actually cuts the seal, which ultimately allows the contents to release and renders you without a workable clutch lever.
There are two ways to remedy the situation: replace it with a Brembo unit rebuild kit (or an entire Brembo slave system) or get a Rekluse manual slave cylinder. It uses a hard-anodized billet aluminum housing and piston for durability and is said to improve the clutch modulation. The Rekluse unit is being used by several factory Husqvarna riders and sells for $159.