head gasket sealer
 

I’m doing another OM603 head today, actually putting a decent 350SDL head on a 300SDL. In the past I’ve always put the gasket on dry, but this time I’m considering using a sealer like Permatex copper spray on the head side. There are a few pits around water passages and the like on the replacement head. The ring where the gasket seals the combustion chamber is clean and smooth. I’m using the latest version MB gasket. Any opinions on using a sealer?

Opinions? Yea, don't do it.

Read the instalation sheet.."..Do not use a sealer..............."

If the corrosion enough to bother you, bead blast the area and apply JB weld to the pits.....smooth off when set with a fine sanding pad.



.

Thanks DK, I had to chuckle though when I read your advice then your Signature line. I've always put them on dry in the past, but I read an email from a shop owner recently that said he always used hylomar when replacing a gasket on a used head. I just don't have the time to go back and do this again and I don't have the funds to buy a new casting.

I've almost always had the head resurfaced anyway. If it's close to straight, a good machinist can resurface it while removing less than .005" of material.

The exception was my H-D Shovel. I never did resurface those heads, and had them off three or four times. Never a problem.

This makes me wonder if my '96 had this problem. Some of you may remember that I had what seemed to be a very tiny head gasket leak that would leave a small amount of residual pressure in the cooling system. Perhaps the original owner had a stuck glow plug and had to remove the head, and the new gasket didn't seal 100%. Just a guess but maybe that's what happened. I ended up using Bar's Head Gasket Repair and now I don't get the residual pressure anymore. I don't know if it's necessary to use a sealant on a new head gasket, but definitely make sure the contact surface is clean and smooth.

And use Victor Reinz gasket if possible, DRY!

http://www.peachparts.com/shopforum/showpost.php?p=890558&postcount=5

The head should always be checked for flatrness, or better yet just have it skim cut to assure flatness, this is routine where an aluminum head is removed and reused.