Stihl MS 460 Oil Leak - not what you may think...

[WoodTruk]

So my trusty 460 just developed the ol' weeping seepage the other day. I did all the standard things of checking the cap gasket, blowing out the vent hole etc. but it kept doing it...not a lot, but enough to make a mess.
Finally in desperation, I started taking things apart to see if there was a small crack in the oil tank somewhere. And then I found it.
Let me preface this by saying I have a 3/4 wrap bar and a metal guard plate on the bottom sold by that dude on FleaBay (highly recommend it, btw). Anyway, after taking off the bar and guard, next were the buffer mount screws. Once those are off, the strip that goes up under the saw can be lifted away a bit without taking off a lot of top-end stuff. There, underneath the T27 bolt holes for the handle and guard on the bottom was a small pinhole that had been rooted out by those bolts sticking through too far. So beware...check that they don't over-travel and punch into your tank as every time you set the saw down, the buffers flex and it's like a little Gremlin in there with a hammer and punch. It took about a year for it to dig and bang all the way through.
I do have a question though...what do you guys recommend to patch the hole? Thought about silicone or JB Weld or some such. There won't be any load on it other than plugging the hole. Haven't fixed it yet and all it would take would be a dab of it. What would seal it up and be resistant to heat and oil?
I've ground down the bolts so it won't happen again.
Thanks!

 

[1Alpha1]

Some good quality silicone sealer should do the trick.

Proper site preparation is the key.

 

[WoodTruk]

Thanks Free Will.
So silicone will hold up against the oil? In that case, maybe I'll try forcing a bit through the hole so it'll kinda 'barbell' through and hold.
I've cleaned it about 5 times with carb cleaner. Think that'll work or should I use some kind of detergent degreaser, brake cleaner, or alcohol?

 

[happysaws]

Brake-cleaner or alcohol, a brass wire brush and compressed air should do it.

 

[Big_Wood]

my favorite repair for things like this is JB stick although, it would be better on a hole that is bigger. i clean everything up good and then mash the JB into the hole. then from both side i form a lump of JB bigger then the hole. once cured it can't go out either way because of the lumps formed on either side. i've never had things leak afterwards. i've used other stuff like seal all and silicone but they usually eventually fail even if surface prep is done 100%.
i did a buddies 372 a while back, same thing with to long of handle screws and rubbing a hole in the oil tank. his literally blew a hole out of it though. probably the size of a nickle. JB stick weld repaired it and it's still fine today. i installed the proper length screw and he was good to go. this is on a production falling saw that see's use every single day too. i'd not hesitate to do the same thing to mine if it ever happened even if i had spare cases sitting around.

 

[StihlNick]

I have used JB weld on oil tanks no problem and has held up to this day almost 2 years. Good engine degreaser and if you can score the surface a bit with some 80 grit or whatever you can fit in there..