KZ400 S2 clutch pushrod leak

Hi there,

I've just gotten my KZ up and running after it sat idle in someone else's garage for 5 years or more and it is leaking oil from the clutch pushrod entrance.

Thanks to the ideas here I tried fixing the leak by glueing on a second oil seal as suggested by Ibsen:

kzrider.com/archive/viewthread.php?tid=29005

Unfortunately, this hasn't stopped the leak. I have checked the new seal and my glue is holding as it should, the oil is definitely coming out from between the pushrod and the seal. The seal itself "feels" good. It isn't as tight as it was when I first put it on there, but that is understandable as it is now covered in oil, and it does look like a great improvement over the original seal which was significantly damaged.

Also, there is a LOT of oil coming out when the engine is running, maybe 10mL every minute.

My question is: does anyone here know of a reason why there might be a pressure build-up behind the seal? As I understand it, the oil shouldn't be under any pressure as it feeds through a long shaft, past a ball-bearing, past the clutch actuator, and even then it ends up in what is pretty much a sump. Yet, the oil seems to be almost pumping out of the seal. I feel as though there is something going on behind the seal that is my problem, or at least is making the problem a lot bigger than just a lousy seal.

Any thoughts, ideas or experience you have would be a big help. Thanks.

Update: hi there, still trying to figure this one out. A friend suggested that my crackcase ventilation might be blocked, so I pulled off the head cover. Lo and behold, it was practically brand new! I guess the last owner must have tried fixing this bit already.

So, I'm still left with the massive oil leak. All I can think of now is that I need to beef up the seal so I'm going to glue on a 1/2" length of brakeline hose from a car.

Anyone got any other ideas?

Is the push rod worn down from use? I'd have somebody measure a new one and compare yours.

It doesn't appear to be worn down in any way as it is uniform along its entire length, although I could take a micrometer to it to make sure. Thanks for the idea.