Topic: 3 years, 3 slaves (hydraulic clutch failures)

[BomberMann650]

Risque title sums it up.
The FJR hydraulic clutch slave took a dump .. again. 

Third time having ordered a replacement from ebay.  2022, 2023, and now.  Some pretty short lifespans considering it was in my possession 4 years before the first one quit.  And the bike was 12 years old at that point
Junkyard replacements because the oem diagram sells it as a complete unit. Charging a kings ransom for new in box.  The allballs seal kit is a gamble on fitment.  Some model years just be different *allegedly*

Would really like to know what is killing these things.  Best guess on the lastest failure it spent a night in a sub freezing temperature.  But the other unit survived life outdoors in TWO sub-zero Kansas winters before calling it quits.  The water content of dot 4 couldn't have gotten that high after a year in the desert could it?

The FSM says use brake fluid.  But if the hydraulic unit is going to crap out, its tempting to flush it and try some alternative.  Maybe one that conditions the seals better.

Thanks for reading about my woes

[scottly]

How many miles on the original? How many miles on the junkyard replacements?

[Alan F.]

Is DOT5 compatible with the materials in the system?

I use this for o-ring compatibility:
 https://mykin.com/rubber-chemical-resistance-chart-3

[BomberMann650]

How many miles on the original? How many miles on the junkyard replacements?

In terms of mileage..  First failure came up after i put 45-50kmi on the machine.  Not knowing if it had already had a slave replaced in its first 35k of life.
That was January 2022.  The junkyard part was a gently used ebay item from 2006.  Got 20kmi out of it. 
November 2023, put on another salvaged part from 06, then basically parked the bike.  6,000 miles for 2024.

Now its February 2025 and the bike is awaiting its 3rd semi-annual transplant.  Scored a takeoff from a 2010.
Hope the all balls seals will fit this piston. Confirmed last night the kit is not a match for the '06 slaves.  Having dug out the left over from 2023.
The possibility of cleaning and reinstalling may be viable.  Little spots of visible wear on the cylinder gland, although the fit feels loose.
Should probably inspect the piston on the handlebar too.

[/Lamentation]

Is DOT5 compatible with the materials in the system?

Its an older model, but might be able to run dot 5.2 - uncertain if a mineral-based clutch fluid would fair any better.