Clutch slave cylinder is leaking?!?

Clutch slave cylinder is leaking?!?
No drippings on the floor. I found this while I was looking for the coolant leak. Who knows when it started, but no longer than a month.
The clutch lever is not engaging first 30-40% - I thought It's something else.

I wonder if this is in a similar location and possibly the same job ?

https://www.st-owners.com/forums/showthread.php?155031-ST1300-Clutch-Slave-Cylinder-Replacement&highlight=

Has the fluid level in the master cylinder dropped? If so, the slave is leaking, but I would guess just looking at that, that it is. This job is nothing like the 1300 job posted by Kevcules. Quite simple compared to that. Check your Service Manual.

It sure looks like you've got a leaking clutch slave cylinder there Afan - but at least on an ST1100 it isn't too hard to get at. The parts aren't that expensive - my ST1300 slave cylinder cost about $75 Canadian late in 2016 (a couple of months ago).

The ST1300 setup is entirely different - the slave cylinder is on the backside of the engine about 6-8" above the centre stand pivot, instead of on the front behind the radiator as it is on the 1100.

Aside from the access to the cylinder, the article that Kev posted may give you some helpful tips because the basic principles are exactly the same between the two bikes.

Pete

Kevcules said:

I wonder if this is in a similar location and possibly the same job ?

https://www.st-owners.com/forums/showthread.php?155031-ST1300-Clutch-Slave-Cylinder-Replacement&highlight=

Click to expand...

God, the post is huge!
Probably will solve my case. Hm... Somehow I missed it...

Thanks!

Bush said:

Has the fluid level in the master cylinder dropped? If so, the slave is leaking, but I would guess just looking at that, that it is. This job is nothing like the 1300 job posted by Kevcules. Quite simple compared to that. Check your Service Manual.

Click to expand...

Yes, sightly under

MaxPete said:

... but at least on an ST1100 it isn't too hard to get at. The parts aren't that expensive

Click to expand...

Thanks Pete. At least one good news today. While trying to find coolant leak I found there is a gas leak and clutch slave cylinder leak. I call it very successful day.

Anybody interested in 1998 ST1100?!?

Yeah, a bit of bummer, but look at it this way: if you fix these things, it will likely be for the last time and also, you'll have been all over the bike so when you are done, you should have a great ride that will be safe and reliable for a long time at a tiny fraction of the cost of a comparable bike, bought new.

It truly is a piece of cake to do. Just did this back in the fall. it is much easier to do it if you know it is happening. What you dont want to have to do is borrow a trailer to go pick it up from downtown Indy with no assistance. Replacement will take around an hour or two. most of that time will be cleaning up where you took the old off and scraping off the old gasket. or and make sure you have a thin walled wrench for the bolt head. Otherwise you may find your self attempting to losen the exhaust.

MaxPete said:

Yeah, a bit of bummer, but look at it this way: if you fix these things, it will likely be for the last time and also, you'll have been all over the bike so when you are done, you should have a great ride that will be safe and reliable for a long time at a tiny fraction of the cost of a comparable bike, bought new.

Click to expand...

True. That's why I invested in December almost $1,000 in new final drive & new Michelin RP3.

Afan said:

True. That's why I invested in December almost $1,000 in new final drive & new Michelin RP3.

Click to expand...

Well, there ya go - nearly done for now then.

I rebuilt my slave cylinder a few years ago, just as a PM measure ( and to P.O. Mr. Bush ).

It's an easy task - just a gasket and two seals ( one big & one small ). You may be amazed at the gunk inside the cylinder. Just clean it up and polish the walls and piston with some #400 & #600 wet-or-dry. Don't clean-out the groove in the piston with anything that may scratch the groove- use wooden toothpicks if necessary. Be careful to note which way the lip on the big seal that seats in the piston is oriented.

After you re-assemble and bleed, there should be about one-half inch of "play" at the very end of the clutch lever before you start feeling some resistance.

The time you spend doing this will be about the same amount of time you would need to kill in the service department waiting room if you had bought a new bike and were waiting for a warranty repair , but you will have more fun rebuilding your slave cylinder.

While you're at it, might I recommend a rebuild of your clutch master, if it hasn't already. At least open it up and clean the gunk out of the master bore. There's junk in there that can block ports which cause the cylinder to build pressure. My brother-in-law had that happen on his brake master and it caused him to have to pull over and bleed fuild in order for the wheel to move. Once we figured out the problem opening up the master and cleaning it out fixed the issue and new seals didn't hurt either.

dkruitz said:

While you're at it, might I recommend a rebuild of your clutch master, if it hasn't already. At least open it up and clean the gunk out of the master bore. There's junk in there that can block ports which cause the cylinder to build pressure. My brother-in-law had that happen on his brake master and it caused him to have to pull over and bleed fuild in order for the wheel to move. Once we figured out the problem opening up the master and cleaning it out fixed the issue and new seals didn't hurt either.

Click to expand...

My experience with several older bikes is that the old seal usually looks like new and can be re-used. It's more important to clean out the gunk and maybe polish the bore with some 400 & 600 wet-or-dry.

Last night I took off the clutch slave cylinder - and it was nasty!
I cleaned it, and looks ok and still in good condition except rubber parts. So, I'm ordering the parts and (11 and 16) but on the fiche there is no part that I had in the service manual I looked at last night (and the book is still in the shoppe ). It's a screw with two rubber (?) rings I wanted to replace too. I checked on several different websites (online stores) but none of them have it.
Anybody knows what am I talking about and what's the item numbers?

Nope.

Afan said:

Last night I took off the clutch slave cylinder - and it was nasty!
I cleaned it, and looks ok and still in good condition except rubber parts. So, I'm ordering the parts and (11 and 16) but on the fiche there is no part that I had in the service manual I looked at last night (and the book is still in the shoppe ). It's a screw with two rubber (?) rings I wanted to replace too. I checked on several different websites (online stores) but none of them have it.
Anybody knows what am I talking about and what's the item numbers?

Click to expand...

Your red arrow indicates the point where the hydraulic line attaches, with the banjo fitting. It needs two copper bushings. Your original bolt should be fine.

Bush said:

Your red arrow indicates the point where the hydraulic line attaches, with the banjo fitting. It needs two copper bushings. Your original bolt should be fine.

Click to expand...

Yes, exactly. Thanks. Now, where (on fiche) I can find the item numbers for the copper bushings? Or Menards/Home Depot are good enough?

The copper washers should never be re-used. The parts illustration shows them as #18 part no. 90545-300-000. There are two washers needed at each end of the hose. It's the same part number for the washers used on the front and rear brake hoses connecting the master cylinder and caliper(s). There's a total of 14 of these washers on the bike. I always keep extras on hand.

You may want to disassemble the clutch master cylinder and clean it up if not replace the piston set while you're at it. Good Luck with your project.

STrolln_01 said:

The copper washers should never be re-used. The parts illustration shows them as #18 part no. 90545-300-000. There are two washers needed at each end of the hose. It's the same part number for the washers used on the front and rear brake hoses connecting the master cylinder and caliper(s). There's a total of 14 of these washers on the bike. I always keep extras on hand.

You may want to disassemble the clutch master cylinder and clean it up if not replace the piston set while you're at it. Good Luck with your project.

Click to expand...

I think it's not #18, that looks different, and not the place I was talking about. And when looked the part # on ronayers.com there is no ST on the list?!?

BTW, I took off only Clutch slave cylinder assy (#7) To take the rest off (the cover with the Honda name on it) I have to take off the right exhaust pipe, right?