Leaking Oil Pan Drain Plug

[canzelc]

Any body have any suggestions on how to fix a leaking oil pan drain plug? I put a new to me used bronco pan on the 91 Mustang motor I swapped in. Ever since I installed the motor it has leaked from the drain plug. I just drained the oil and replaced the aluminum crush washer with a copper one one the advice of a friend and it leaks worse. After it was leaking more I tightened the plug to 40 ft/pnds (spec is 25), still dripping.

Any ideas?

 

[EricLar80]

They sell repair kits:
https://www.youtube.com/watch?v=n45dU6wGZq0

 

[KyddsPly]

Pull the plug again and check for a crack at the hole. If all is good, use a fiber based washer.

 

[KyddsPly]

Pull the plug again and check for a crack at the hole. If all is good, use a fiber based washer. Shoul be good to go.

 

[DJs74]

Depending on what you find when you re-inspect and if you still have a problem, you can search for what's known as a "stato-seal"

A stato-seal is a metal washer with a molded rubber seal on the ID, they are made as one piece. The rubber ID has a raised lip on both sides and will seal around the drain hole and the metal washer will serve as a positive stop so the torque will not squeeze the rubber seal out. Basically, when you tighten the drain plug down and reach the limit of the metal washer, the rubber will have the right amount of compression to seal around the hole without migrating / displacing itself.

I've used them in a lot of applications where a compression seal is needed but there is no metal lip or groove present to maintain the seal from squeezing out. They work the same as bronze type washers but better IMO because they are an elastomer seal - just be sure to choose the right material for the job... oils and fuels need NBR or FKM material. Water applications are safe with EPDM material.

Sources: McMaster-Carr, possibly your local hardware store or local automotive stores



DJs74

 

[canzelc]

I just looked at the McMaster-Carr website and I think the stato-seal will work and for a good price as well. Does anybody know what the bolt size the drain plug is? I am guessing it is a 9/16", but I am not sure not sure. I may have to pull it out to verify.

Thanks

 

[DJs74]

I just looked at the McMaster-Carr website and I think the stato-seal will work and for a good price as well. Does anybody know what the bolt size the drain plug is? I am guessing it is a 9/16", but I am not sure not sure. I may have to pull it out to verify.

Thanks

I would just pull the plug and measure it with calipers or a ruler. You'll want the ID of the stato-seal to fit snug on the drain plug - not tight enough that you have to force it over the threads because you might damage the rubber seal surface but not so loose that it shifts side to side.
Once you know the plug diameter, choose the stato-seal with an equal to plug diameter or a few thousands bigger than the plug thread size.

I assume your plug has a larger diameter bolt head and/or washer which will work well with the stato-seal - if not, use a large flat washer too. The stato-seal will not like being twisted on too much. The best case scenario is that your bolt hex head will turn on a metal washer and the stato-seal will remain stationary while its being compressed.

Good luck,

DJs74

 

[66broncoCT]

On my 300 the plug was 1/2-20. Advance auto parts sold a set of 4 oil drain plug seals that had a copper washer, the stato seal, a plastic seal and a fiber washer for $4. Mine had a worn out plastic seal so I replaced it with the stato seal.