The sump plug on my car has always leaked, even though the plug is new and new washers are used too. Perhaps the hole isn't dead square to the face or something I'm not sure, but has anyone seen any sump plugs with o rings, or used dowty washers before, or anything else?

Hope its not a crack in the thread of the box
Sometimes the crack will open up when the bolt is tightened. Have you tried non hardening gasket glue or hydraulic thread sealant.

A bit of gasket goo should work I usually use the blue or red stuff as shown here
viewtopic.php?f=25&t=47609

on 1 of my old cars i had a leaky sump bolt & i put the high temp locktight on it, worked a treat, just let it dry for 10mins before adding oil & then allow the required curing time

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I have used a white loctite thread sealer with great success.

I have put 2 thin o rings on the sump plug , they fit inside the copper washer and holds it centred ,
then I put one of those red fibre washers on , ( same size as the copper washer )
No leaks ,

Mark

dowty seals work great, you can get a self-centering one IIRC.
if nothing seals i glue in this one as you don't have to remove it again to change the oil, i'm sure you can find similar
http://www.limora.com/de/olablassventil-161968.html

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Rover 214 atm ....

Mine was not square and had a crack from where the case had hit the ground before i got it. Ended up having the crack plus hole welded up at work and the hole rebored. Then tapped out to take one of drmini in aust(Kev)'s steel adapters. Sealed the adapter thread to the box with loctite and the mating surface is perfectly square to the internal thread for the sump plug.

A bit of work but damn thing is never going to leak again that's for sure.

cheers
michael

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