Questions about gasket sealants

[Motorhead]

I am doing an OIL cooler replacement on a friends 1992 W250. While we are there, I am going to do the Killer Dowel Pin check and tab. I ordered all parts for the oil cooler and front timing cover gasket from Cummins. The timing cover gasket is the metal type. What type of sealants are recommended for this gasket and for the oil cooler? I bought some non hardening Permatex gasket maker. Any other recommendations?

 

[Motorhead]

Guess I take this question to another generation forum.

 

[DVolk]

You can use rtv if you like a thin coat . The book actually calls for copper coat of which tends to be a slittel slimey

 

[Motorhead]

Thanks for the recommendation. I have used Copper Coat for many years.

 

[cerberusiam]

I use a thin coat of RTV to hold it in place and help sealing.

 

[Motorhead]

Thanks, This is one of those jobs I only want to ONCE. That's why I am asking about the proper sealants. One nice thing about working on a first gen is LOTS of room under the hood.

 

[ENafziger]

I used copper coat on mine recently. The local Cummins dealer had a good Fleetguard product made to flush the coolant system of oil residue for this exact situation (I'm assuming the cooler cracked and sent oil into the coolant and coolant into the oil).

--Eric

 

[Motorhead]

I used copper coat on mine recently. The local Cummins dealer had a good Fleetguard product made to flush the coolant system of oil residue for this exact situation (I'm assuming the cooler cracked and sent oil into the coolant and coolant into the oil).

--Eric

Eric, I saw you write up on your cooler leak. The truck belongs to a long time neighbor. This cooler hemorrhaged oil into the cooling system too. It looks like it cracked right where the cooler feed tube is brazed to the cooler plate. One thing I noticed on the new cooler is that the cooler plates themselves is now fixed to the cooler plate by copper braze. I ran two loads of Cascade through the engine then a gallon of Fleetguard restore. I said to my neighbor that it is a good time to check the KDP to see if it has migrated out and to put the tab on it. It had only migrated a little bit and I made up a tab and put Loctite on the bolt. The Permatex Gasket maker isn't a silicone. it seemed more like Copper Coat in consistency.

 

[B.G. Smith]

I have used copper coat and had good results with it. I also have just coated the gasket on both sides with wheel bearing grease and it seals plus seems to keep the gasket from becoming brittle over time. bg

 

[Motorhead]

B.G., I have used grease a lot on paper gaskets. It does keep them supple and I have never had one leak when I used grease. The timing cover gasket was a stamped steel with a coating on it. I'm sure you could probably put it on DRY on a NEW engine and NEW timing cover but with a 1992 and 216,000 miles on the clock, I chose to use the sealant also.