seized clutch slave cylinder

[RodneyT]

Apologies if this topic already exists but after much searching I couldn't find anything.

I took the slave cylinder off as the master cylinder piston was also seized in the bore and fluid totally dried out and assumed the slave cylinder would be in the same condition, as has proved to be the case.

I cannot budge the piston with compressed air so thought if I pushed it in a smidgeon it might break whatever is holding it. Managed to move it about 1mm but it still wouldn't budge. Squirted some WD40 around the edge of the piston in the vain hope that might help, but no. The piston appears to be in almost as far as it can go

Next step was to try gently heating the body of the cylinder but that made no difference, either.

The only thing i can think of now is drilling a hole in the middle of the cover and whacking the piston out with a punch then tapping the hole and putting a bolt in it to seal it back up again. This is all assuming the bore is still OK or I don't wreck it getting the piston out...

Does anyone have any bright ideas on how to remove the piston?

I can get one from a UK wrecker for about 20 quid (and the postage to Australia is almost as much again) but who knows if that one will be any better...

[RodneyT]

The other option I thought of is convert to cable using a Varadero sprocket cover. The metal plate between the cover and where it bolts to the crankcase is the same on both models so the mounting holes would line up.

Has anyone done this mod?

However, a 2nd hand one is dearer than a 2nd hand slave cylinder...

[MacV2]

http://vtr1000.org/phpBB3/viewtopic.php ... 843e987a03

Varadero clutch conversion.

[RodneyT]

Update... Had a mate come round to have a look and he's had several Ducatis with hydraulic clutches he's refurbished and showed me a trick for freeing the piston - bang it down hard onto a block of wood to try and displace the piston. Unfortunately, that didn't work but banging it down onto the back of the vice a few times showed it starting to move. once that happened, out it pops when compressed air was applied again.

Wasn't much holding it in place and it has all cleaned up remarkably well... all I need is a seal kit at both ends.

I was planning to flush the line with alcohol starting from the top end and then reverse flushing from the bottom end and continue until the fluid runs clear. Maybe leave it filled overnight and then repeat. Any other advice?

[fabiostar]

The clutches are a pain in the ass to bleed on these.. it normally goes nothing nothing swearing nothing cursing nothing bang its done

[sirch345]

Rodney, good to hear you got the piston out eventually, even better you only need a seal kit

As Rob (Fabiostar) says, they can be a pain to bleed.
When I fitted new seals in the slave cylinder on my Storm I back bled the system from the bleed nipple on the slave cylinder using a big syringe, it worked a treat. Using PTFE tape on the bleed nipple threads stopped the fluid coming out from there,

Chris.

[RodneyT]

Many thanks for your comments, guys.

I was planning to fill the clutch hydraulics from the bottom using exactly that method and have found the value of thread tape on the bleed nipple - when using a vacuum bleeder all it did was suck air through the threads until I taped it up.

I've also had to pull the front calipers apart and give them a very thorough clean as well. Unfortunately, 3 of the pistons had enough corrosion near where the seals would be to concern me so have plumped for a set of new stainless ones. Ya can get by without a clutch if a seal fails....not so much with the brakes!
Was also thinking of pushing fluid into the brake hydraulics from the bottom up via the bleed nipple. I figured if I go slowly this should help fill the space behind the pistons with fluid without trapping air. I'd have the whole system off the bike and the master cylinder/lever mounted on an old handlebar in the vice so I can have the lines completely vertical. I'm thinking this way would be pushing the vast majority of air up to the master cylinder and, once filled, I'd then bleed in the conventional manner. Hopefully this would be quicker than the hour or so it took me on my last effort on my Triumph Sprint.

Next job is the valve clearances and CCT mods - got some new ones just to be sure as I have no idea how old the current ones are or the milage of the bike

[sirch345]

Many thanks for your comments, guys.

I was planning to fill the clutch hydraulics from the bottom using exactly that method and have found the value of thread tape on the bleed nipple - when using a vacuum bleeder all it did was suck air through the threads until I taped it up.

I've also had to pull the front calipers apart and give them a very thorough clean as well. Unfortunately, 3 of the pistons had enough corrosion near where the seals would be to concern me so have plumped for a set of new stainless ones. Ya can get by without a clutch if a seal fails....not so much with the brakes!
Was also thinking of pushing fluid into the brake hydraulics from the bottom up via the bleed nipple. I figured if I go slowly this should help fill the space behind the pistons with fluid without trapping air. I'd have the whole system off the bike and the master cylinder/lever mounted on an old handlebar in the vice so I can have the lines completely vertical. I'm thinking this way would be pushing the vast majority of air up to the master cylinder and, once filled, I'd then bleed in the conventional manner. Hopefully this would be quicker than the hour or so it took me on my last effort on my Triumph Sprint.

Next job is the valve clearances and CCT mods - got some new ones just to be sure as I have no idea how old the current ones are or the milage of the bike

I have found back bleeding as you are thinking of doing for the front brakes, to be the best way to bleed the air out of them

Chris.

[Donut 77]

The clutches are a pain in the ass to bleed on these.. it normally goes nothing nothing swearing nothing cursing nothing bang its done

Exactly what I discovered this week. I thought there was a problem then suddenly, perfect clutch

The clutch slave was seized when I found my bike - rusted up. I got one from eBay for £20 just the job. It’s due IMO to the odd way that Honda designed the cover plates in and around the slave piston, they are prone to failing at the weird gasket as some of the bolts go through two mechanisms.