Clutch slave - replace or not?

[roggie]

In past threads Oberon seemed to be the preferred choice. Is it switching to the Yoyodyne now? Or are they both fairly equal?

[SpikeC]

 I got a gold colored EVR slave and it added 10 horse power! (To the look of the bike)

[roggie]

I got a gold colored EVR slave and it added 10 horse power! (To the look of the bike)

Spike, excellent point!

Please include any horsepower graphs for said option...

[d3vi@nt]

I've read (pretty sure here) that the stock slaves are largely responsible for clutch fluid turning dark/dirty quickly. I experienced this on both my Monster and ST2.

I assumed this was due to inferior build quality as compared to the aftermarket pieces. If true, this would be another argument to replace with aftermarket.

[ducpainter]

In past threads Oberon seemed to be the preferred choice. Is it switching to the Yoyodyne now? Or are they both fairly equal?

Dunno. I think it's more my tech likes dealing with Fred.

[Armor]

Clutch fluid still turns dark with aftermarket (Oberon) slave.

[oldndumb]

I've read (pretty sure here) that the stock slaves are largely responsible for clutch fluid turning dark/dirty quickly. I experienced this on both my Monster and ST2.

I assumed this was due to inferior build quality as compared to the aftermarket pieces. If true, this would be another argument to replace with aftermarket.

An often quoted tale.

My opinion is that a clutch MC piston experiences more travel than one in a brake MC. More piston travel equals more seal wear leading to a conclusion that the clutch fluid should darken faster than the brake fluid.

[Howie]

Lots of theories why this happens.  Aluminum from the bore, rubber from the seals and heat.  Until recently I thought heat was the least likely since clutches don't produce much heat and brakes do.  Then I noticed black fluid in the reservoirs on water cooled Multistradas.  The resrvoir is very close to the cat equipped exhaust.

[NAKID]

I've got over 32K miles on my stock slave. No issues so far...

[d3vi@nt]

Clutch fluid still turns dark with aftermarket (Oberon) slave.

Same rate as with stock? Just curious...

[koko64]

Went to a local hydraulics guy who made custom seals. I got a spare (rare custom made from Brad) and this guy could do the same as the people in Sydney (iirc) who made the ones Brad had.

The guy said that the various rubber compounds available were not always compatible with different brake fluid compositions from the various fluid mfrs. Some brake fluids ate some rubber compounds more than others and there was evidence of rubber degradation from certain chemicals in the some brand fluids. That's all he would say.

My guess is it may depend on the fluid you use and the compound of rubber used in particular batches of seals from the oem supplier. You won't know according to this guy until the seals fail early and inexplicably. It may be hard to know if there was another less obvious cause besides a buggered thrust bearing or rotten fluid.

He said that he could have a seal made that would stand up to current known chemicals in brake fluid, but he would give no guarantee. Food for thought.

My concern would be that NOS of oem slave cylinders and NOS of rebuild kits may not be compatible with the stuff in the latest brake fluid, if this guy is to be believed. I 'spose you could be lucky or unlucky. My old model type slave cylinder is still going, touch wood, but I would gamble on the rebuild kits for the old type if they were cheap enough.

[ducpainter]

The rebuild 'kit' consists of a single seal.

Last I remember it was about $8.

[silas]

My red Ducabike slave works great ('98 M900) and lessened the lever effort. My hands have had a lot of -bike accident-trauma & breaks, so that helps. The original one was working great when removed at 32k, no leaks. Had to easy out one if its 3 bolts. I was updating everything else on the clutch anyway (except master) and I also love the Ducabike slipper clutch. The fluid gets black sooner than the brakes on all of them it seems. Maybe not quite as quick now as with the oem unit. Ducati life. It seems to really bother some people : )

Before the HEL Performance line went on-