I rebuilt by '01 24 valve truck and ran fine for a day. After driving about 5 miles to the store it started leaking on the passenger side at the oil cooler. Is there a particular trick to putting those on? Also another possibility is the AC bracket. When I put that on I didn't realize a gasket went in the block. I got that gasket and ordered the oil cooler gaskets to put in tomorrow. I'd appreciate any advice or insight on that.

Throw the silicone and copper spray in the garbage can and almost all your head aches will be cured......Put the gaskets on dry and clean and they will seal. If they needed something else to help them seal they would come with it already infused into the gasket.

Well i used a little sealant when i rebuilt my engine at 450k not a leak yet at 768k,guess i really messed something up!

Well i used a little sealant when i rebuilt my engine at 450k not a leak yet at 768k,guess i really messed something up!

I have seen 2 engines off the top of my head that failed due to RTV. 1 had so much rtv inside the engine is completely plugged the oil pickup screen, the other was used in place of a gasket on an oil cooler which you can imagine what happened. RTV doesn't hold pressure. lost all the oil and spun some main and rod bearings. Both do it yourself mistakes that could have been prevented with proper cleaning and gaskets. Where, what type, and how much sealant is the thing that most people don't have a clue on. In most cases it is best to leave it out of the equasion unless there is a need for a specific product in an area. Most leaks are caused by a dirty uneven surface and improper torques which cause warping ect. I do this for a living, these little 5.9 engines are like a lawn mower engine to most as I work on half million dollar v12 and v16 diesel engines so I know a wee bit about how critical leak free needs to be as "MSHA" Mine safety and health administration Can slap extremely high fines on companies for leaks on equipment.

Don't need to get in a p****ing contest over trying to help this guy,but if your read my post i said(a very thin coat) just enough to fill any small imperfections on either surface,not in place of a gasket.But i'm Impressed with the v12/v16 engines

I didn't use RTV on either gasket. After we took the first one off we could see where it failed. It was fiber and the second one is metal. It just seeped a little and only left a small puddle once. I don't know why I'm havign such a problem and not aware of a particular torque sequence.

not aware of a particular torque sequence.I am not sure myself just trying to cover all bases.

I didn't use RTV on either gasket. After we took the first one off we could see where it failed. It was fiber and the second one is metal. It just seeped a little and only left a small puddle once. I don't know why I'm havign such a problem and not aware of a particular torque sequence.

Generally, you tighten the bolts in the center and work your way out. So get them all a little tight, then tighten the top middle then bottom middle, then top left of middle then bottom right of middle... Just keep going top to bottom and left and right. Its the same way on things as thin as oil pans or as thick as the cylinder head.

Here is an oil pan example so you see what I mean.

As for gaskets with or without RTV, I think the application has a lot to do with it. Oil pans are warped a lot of times in between bolts so I always get some "The Right Stuff" and put thin coat on both sides of the gasket. As for the oil cooler, it is thicker so I don't think would need any kind of sealant.

That's my A *thin* coat of RTV like Blueox01 said couldn't hurt, but I think making sure the mating surfaces are perfect would allow for just the gasket without RTV. Did it leak out of the fiber or metal gasket?

The "Right Stuff" is the best of the best when it comes to a silicone type sealant.

I've cheaped out a few times and just found myself going back to buy it. That stuff is like 4x more than RTV but it's worth it. If you don't waste the stuff it actually goes a long ways.

The fiber gasket had a big leak and even leaked when the engine wasn't running. The metal one sprang a smaller leak that didn't make it to the ground and didn't use RTV or silicone on either one. But it started to only leaking periodically but still not making it to the ground.