Putting my 3GM30F back together and my Yanmar Service manual(older version) states to coat both sides of the head gasket with Three Bond 50. Of course it appears that this product is no longer available. I spoke with the local Yanmar Service Manager and he says that they don't put anything on the gasket; apply dry and follow proper torque specs. Any comments and recommendations from anyone who has replaced the head gasket would be greatly appreciated. I want this rebuild to be perfect. Thanks as always.
YANMAR 3GM30F Head Gasket
- Thread starter Rick2413
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Maybe the gasket is different than the original? Is there a soft coating on the gasket that kind of looks like the coating on a scratch off lottery ticket?
I haven't messed with this yet, Rick.. But it could be that the old gasket had asbestos in it and it had to be modified to get the asbestos out. I know on the 3 GMF (not 3GM30F) that the gasket now has a different part number than it used to have. Hermit may have the answer... if there is a soft graphite coating on it, it probably is a new design (Grafoil) and doesn't need any compound gook on it.. Three Bond 50 is an RTV gasket material that is a high temp non solvent type RTV.. probably like Fel Pro Black RTV or Permatex Blue .. I would go with the mechanic's recommendation IF the gasket has a graphite coat and if it doesn't have the graphite, I would coat it lightly with FelPro. Good luck with that one!
we split a 2gm that also states no head gasket cement.
We put the head back and torqued it to spec. It leaked. Went back to Cummings a and told them what had happened. A older gentlemen said put a little cement on it and torgue to spec.
5 years now no leak. I found the yanmar manuals are very inaccurate with info.
Try and find the info for the main bleed screw in a 2/3gm older manual.
Good luck.
We put the head back and torqued it to spec. It leaked. Went back to Cummings a and told them what had happened. A older gentlemen said put a little cement on it and torgue to spec.
5 years now no leak. I found the yanmar manuals are very inaccurate with info.
Try and find the info for the main bleed screw in a 2/3gm older manual.
Good luck.
After your responses I had another look at the gasket and it does have a shiny graphite side to it(the down side). I think I'll hold off for the weekend to see if any of our forum diesel mechanics has any advice before bolting it down.Thanks for your input.
On every gasket on my ysm12 I coated them with antiseize except the head gasket because it had the scratch off lottery ticket coating on it.
That was on the advice of the most respected engine builder in san antonio.
That was on the advice of the most respected engine builder in san antonio.
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