oil leak question.

[rsoffar]

this is not my bike but i dont know what the part is called so thats why this pic is here... the little silver part right in front of the sprocket cover on this bike.... what is that called? and does that have a gasket behind it? i have a pretty nice little oil leak and it seems to be coming from behind that part.

[Slide Panda]

Crankshaft cover.

It doesn't have a normal gasket but there is an o-ring that sits in side a recess.  Pop it off and have a look.  I can't think of a reason why that seal should fail, since it's not really stressed.  Perhaps it's not tight enough...

Taking it off won't do any harm at all - though if you do have it off, expect a little oil (few drops) to run out, so have a rag handy.

[uclabiker06]

The silver thing directly in front of the sprocket cover is your slave cylinder.  The silver thing in front of that is the crankshaft cover.  Slave cylinders are notorious for leaks and your best bet would be to replace it with an aftermarket one (i.e. STM, Yoyodyne, Evolozione, or if money is no object NCR).  You need to clarify weather you are referring to the slave cylinder or the crankcase cover.

[rsoffar]

slave cylinder is what im talking about... thanks.

if i pull it off is there gonna be oil going everywhere?

and im not certain that is the source of my leak but im pretty sure... its leaking enough to be running down my kickstand and dripping off the front bolt of my rearsets....

[Slide Panda]

Well 1st you need to be sure it's oil.  As mentioned the stock slaves have been known to leak.  A lot of the time this is caused by the push rod turning, due to a worm throw out bearing in the pressure plate.  That turning push rod eventually causes leaks in the seal around the slave piston. 

So make sure what the fluid it - oil or brake fluid 1st.

If it's hydro you'll need to replace that seal around the piston - but it's probably easier and just as expensive to get a used OEM slave.  And there's the alternatives mentioned by UCLA.  And if it's hydro, you'll want to have a look at your push rod and pressure plate, if you can get at the latter.  Look at the push rod for signs that it's been turning.  And if you can get at the pressure plate, have it off and check for any roughness in the bearing as the plate turns.

If it's oil - there's a few places it could be coming from around there and you'll need to hunt it down. 
There are seals on the push rod that wear over time and can leak oil - especially if the push rod has been turning

There's seals around your main output shaft.  Not known to leak - but it can happen.

And, as I learned recently it's not uncommon for a leak to develop between the main case and the alternator cover - right by that slave.  The action of the slave pulling on the cover, slowly weakens that seal over time.  I just took care of this exact problem on my bike.  My 1st thought was the seals on the push rod is it *appeared* oil was coming out from behind the slave - but it was just getting up there due to the freak nature of oil when it's leaking.

[rsoffar]

well i just cleaned it all up and did the foot powder test and it seems im leaking where the main case meets my left and right covers and from the slave cylinder. lucky me lol   

[uclabiker06]

Perhaps it's not tight enough...

Before you do anything it would be wise to check the torque on the slave cylinder bolts to make sure they did not vibrate loose.  Then take it for a ride and if there is no leak, then your bolts were too loose; problem solved.

[Slide Panda]

Before you do anything it would be wise to check the torque on the slave cylinder bolts to make sure they did not vibrate loose.  Then take it for a ride and if there is no leak, then your bolts were too loose; problem solved.

Huh?  The bolts that connect the slave to engine case would have no effect on anything leaking.  One can, in theory, totally remove the slave - leave the push rod in place and run the engine w/o leaks.

rsoffar - give it another cleaning - make sure to pull off the slave, it's rubber booty and all and get in that recess with towels and such.  When my bike had it's leak, the leaks was behind and below the clutch slave - but oil managed to work uphill and get into the cavity where the push rod passes through.  Leaking oil does some freaky stuff - like traveling uphill