Quote from: Motofun on April 10, 2026, 06:52:29 AMspot on...and hose off that leaking brake fluid before it destroys the paint  (probably too late) 

DOT 5 for me, no need for me to worry!

Quote from: red on April 10, 2026, 10:19:55 AMIt would be my choice to replace a bad clutch slave cylinder with a new one, and maybe rebuild the old one when and if time permits.

I've recently acquired a Bridgeport vertical mill and may try to put a stainless liner in my OEM one like others have done.  As if I'll ever get through my project backlog and actually do that...

It would be my choice to replace a bad clutch slave cylinder with a new one, and maybe rebuild the old one when and if time permits. That old thing has probably done enough, so far, and I would not go to any real trouble to "save" it now. Any corrosion or gouging inside the cylinder would be more trouble that it is worth, to me. I would favor a new one especially if it came with an upgrade steel inner lining.
If you favor SpeedBleeders (.com), this would be a good time to add one there. Those folks will know which one you need.

I've had poor luck with the stock slave cylinder even when the bike was pretty new.  Seems like every couple of years I'd have to pull it off and apart, clean up the corrosion, and put it back together.  Last time it only lasted a few months and I ended up buying a new Oberon slave cylinder.  So far it's great.  I think you can also get a new slave from RPM if the corrosion inside the cylinder is too bad.
https://www.oberon-performance.co.uk/yamaha/yamaha-clutch-slave-cylinder

https://www.rpmracingca.com/proddetail.asp?prod=Clutch%3A5EA-16381-00%3A36y-16381-00
RPM also has a rebuild kit for the slave.
https://www.rpmracingca.com/proddetail.asp?prod=Clutch%3AS%2FK&cat=39

spot on...and hose off that leaking brake fluid before it destroys the paint  (probably too late) 

Rode the bike yesterday and noticed the clutch would only disengage the tranny at the very end of the clutch lever travel, which was something new.  By the time I got home, the clutch would not disengage at all and I had to limp home in second gear.  Clutch lever felt very spongy with little resistance.  I opened the clutch reservoir and the level was low.  Refilled and bled the system with a vacuum pump multiple times - unable to generate any resistance at the clutch lever or to get rid of air in the system.  I then took the slave cylinder off and found brake fluid on the engine side of the cylinder.  That should be dry correct?  If there is brake fluid there, I assume it is leaking past the slave cylinder seal.  In my little brain, that would explain the loss of brake fluid and inability to bleed the system.    I believe I need to replace the slave cylinder seal and dust boot, clean up any rust on the cylinder and housing, reassemble, add fluid, and bleed.  There is a an oil seal on the clutch rod but I didn't see any oil when I took the slave off so I don't think I need to replace that oil seal.   Does my  diagnosis and logic sound right, or am I missing something ?

it's giantkillers fault I have one..

zero26tb4u,
With a breaker bar and a cheater pipe, I would hesitate to hit the cheater pipe with a hammer. I would get the bolt hot, as you did, but I would want the hit the bolt head as if it was a nail once or twice, then trying the breaker/cheater again. Sometimes a powered impact driver can get things going, if you can manage that.
As things worked out, nothing succeeds like success, so cheers for that much, certainly. Glad that the bolt was stronger than the thread-locker, for you. Sometimes it is the bolt that loses the contest. D.A.M.H.I.K.

I know this is an old thread but when looking for information about replacing the left side crankcase seal that resides behind the ignition coil pickup this was the thread I ended up on and I thought I'd add some of the information I didn't find here but ultimately discovered.

As of this moment I have not removed the offending leaking seal as the new one hasn't arrived yet but I figured I would move forward with removing everything in front of or outboard of the seal in preparation of the job. So I started with removing the bolt that secures the pickup rotor to the crank and that is where my questions began because that bolt was ridiculously tight, so tight in fact that I began to wonder is this thing loaded with red loctite or reverse threaded. It is not reverse threaded but it was loaded with red loctite, something that no one else posting about this repair ever mentions, and even after heating the bolt with a small tipped torch, just to keep the heat on the bolt, I still had to smack the back of my 14" breaker bar that I had added another 14" of steel pipe to for additional leverage with a hammer to get this thing to move. So, if any one is having difficulty getting that bolt out, I hope this helps. 

Quote from: zero26tb4u on April 07, 2026, 08:58:53 PMLooks like the 12th to the 17th or 18th for me.

Rumpty too?