qmikep

I have the cummins b series manual however it doesn't list sealants for a bunch of gaskets. This concerns me as I've never had the much luck with gaskets installed dry on other things(transmissions, cases etc.) I was hoping to get some advice on what you guys use on your engines. I am currently replacing the following do to leaks:

- Timing gear housing to block .

-Oil cooler gaskets

-rear main seal housing gasket.

-tappet cover gasket

-oil pan gasket

The timing gear housing to block gasket is specifically concerning as it is quite a lot of work to remove the pump, cam and everything else to replace it. The gasket is a pinkish paper cork looking material and I do not want to have any leaks from there any time soon. The rear main seal housing gasket is a similar pinkish material however it appears to have strips of blue rtv or similar pre coated on it. (all gaskets are genuine cummins).

Second in line of difficulty is the oil pan. All the manual says it to put a bead of silicon at the joint where the block, oil pan, and timing case or rear seal housing meet. However the manual lists nothing on the pan gasket itself.

Any tips on sealant to use as to have a leak free engine would be most appreciated!

Angry Johnny

If your surfaces are clean and flat you don't need any sealant. I never use any except a little RTV where pieces are joined like the manual says.

torquefan

The general guidelines are:

paper gaskets should usually be coated with a liquid or spray sealant before installation.

composition gaskets should usually be installed dry. This includes most gaskets that our engines use; they are often paper with a bead of sealant already added.

rubber seals, such as o-rings, should be lubricated slightly before installation, unless the manual says otherwise.

as mentioned, a small bead of RTV sealant should be added where a gasket goes across a joint between two parts.

I often use a few small dabs from a tube of yellow weatherstrip adhesive (contact cement) to glue a gasket in place if it is at risk of slipping during installation.

This is how we were all taught in tech school, years ago. As with most things, specific manufacturers' instructions should take priority.

Jim Lane

When I was a mechanic for La County we used GasketCinch on Cummins and Detroit engines, like everything else, it has to be applied correctly to work.

death row dave

CORRECTLY is the answer . A touch to much of RTV squeezed out and ends up in a piston squirter ( Oiler ) will make for a super bad day . Follow directions by the word results will great . THE RIGHT STUFF is the best I have found in a long time . The old BTS shake so much that I use blue Locktight on every fastener . Most , leaks come from fasteners loosening from vibrations and gasket shrinkage .

edwinsmith

Don't these engines have full flow oil filters? If so then the filter should catch stuff like this. However I have seen oil pumps jammed up with debris and the distributor/cam gear destroyed in a ford.

death row dave

edwinsmith

My question is: If the engine oil is full filtered, meaning ALL oil is filtered before going to the oil galleys and then to the crank and piston oilers, then how does excess RTV sealant get to the oilers to clog them up? This assumes the correct oil filter is used. If you're not using the correct filter then .

death row dave

cougar

Dave, some people won't believe it until they see it for themselves. I've seen it on failed aircraft engines. Both Continental and Lycoming engine manufacturers have put out service warnings about it. That is why I don't use it on engines, period, ever. How it gets there Ed is very simple. I gets into the oil system after the filter everywhere an oil galley pass through a gasket or a fitting or plug that has RTV on it. What I do use is a silicon grease called DC 4 on gaskets and o-rings, sometimes a waxier grease referred to as fuel lube if the gasket or o-ring needs to be held in place. The advantage is, the gasket comes off clean when removed or if you need to move (as in re-time) something it doesn't tear the gasket when you rotate the item. Otherwise, on rough or uneven surfaces I use aviation permatex.

edwinsmith

Yes. I understand about it going onto surfaces AFTER the filter. I was trying to elicit that info is all. I didn't mean to be disrespectful. Sorry Dave.

Edwin

death row dave

patdaly

Very few people realize most every engine has a bypass oil filter, and as little as 30 percent of your oil can actually be run thru the filter.

The bypass valve not only protects the engine in the case of a plugged filter, it is a relief when the oil is too viscous ( cold ) and would otherwise overpressure.

No need to apologize Dave, this is how some folks learn things.