Clutch lever builds no pressure and slave leaks

I have my $250 '93 fired up and brakes are bleed but the clutch lever seems to build no pressure. I initially bled the clutch line and cleaned it all out but the slave just started leaking so I bought a slave rebuild kit and swapped out the old with the new. Put it all back together and bled the line again but still, i get no real pressure at the lever and it started leaking at the slave again. I can tell the slave isn't pushing the clutch rod at all.

The bike sat for a little over two years before I rescued it. Is it possible the clutch or somethin internally is seized and not allowing the clutch slave to create enough pressure to push the rod and disengage the clutch thus, forcing the fluid out of the slave? This is the last thing before I can take it out on the street.

Any suggestions of the problem or what to troubleshoot next?

Did you use oem seals when you rebuilt the slave?

Did you clean the piston with fine grit sandpaper?

Did you try bleeding the slave off the bike, piston clamped fully in?

Have you used a mityvac to get all the air out? With the slave removed & piston clamped you can lift the slave so the air goes to the slave & out the bleeder.

The clutch plates could be stuck together, but your slave should not be leaking in any case. You have one issue, or two. Fix the known issue first.

SEBSPEED

Did you use oem seals when you rebuilt the slave?

Did you clean the piston with fine grit sandpaper?

Did you try bleeding the slave off the bike, piston clamped fully in?

Have you used a mityvac to get all the air out? With the slave removed & piston clamped you can lift the slave so the air goes to the slave & out the bleeder.

The clutch plates could be stuck together, but your slave should not be leaking in any case. You have one issue, or two. Fix the known issue first.

Yup, used OEM seals.

Nope, didn't think I should be sanding anything in there even with fine grit but I'll try it.

Yup, bleed on and off the bike. Only leaks on the bike.

Yup, mighty vac also tried. Only made it leak faster.

Checked the clutch plates. Wanted to look at them anyway since the bikes past is unknown. They were not stuck together but the steel plates all had signs of some burning. I'll probably be changing all of them out now with springs since the covers are off and waiting to be powder coated.

I'm thinking it's the slave itself and I should sand it down. It isn't as smooth inside as I think it should be.

Thanks Seb.

Any sealing surface should be smooth and pit-free. Inspect your seals to make sure you haven't damaged them. A green scouring pad (steal one from your wife!) will work nicely to remove light corrosion/oxidation. Use 600 grit or finer on any stubborn build up.

Chances are you got some rust and/or pitting from the old seal failing.

I removed my clutch slave only to paint it, the piston and seal were in good shape, but there was a bit of buildup from years of use, so I hit it all with brake cleaner, and used the 3M pad to scrub the piston and bore before reassembly.

Haven't bled it out since, but I expect no problems with it as it was not leaking before.

I would say for yours, to disassemble again, clean, and pay careful attention to the inner bore surface and piston surface.