Oil cooler pipework leaking - how to seal

[Iain]

I have a male-male threaded adapter going into my sandwich plate, M16 to 1/2 BSP, then two 90 degree 1/2 BSP unions coming off that to my cooler.

They keep leaking from the unions (not sure which, assume 90 degree to thread)

I've had them off, cleaned them up and refitted with PTFE tape but not sure if this was the right thing to do?

What should I try next? Is there a proper oilproof sealing tape I can try?

[scott.parker]

lol there was me thinking you had such a nice job done there, looks like you got the same issues as me..

Mine are leaking form the solid to rubber joint.

[MK999]

As long you put PTFE on in such a way it seals the threads and doesnt end up flapping off into your oil system it'll be fine. Check out plumbers jointing paste if it still leaks (not sure if it's oil proof, do your own damn research lol), but PTFE should be fine.

[brainsnova]

There's gas ptfe tape which is like insulating tape thickness so you dont have to wrap the threads a million times

[Iain]

No Scott my usual shoddy job with flattering WIP pictures to make it look good I'm afraid lol

I think it's this stuff I used, bought for when I was making my air compressor lines: http://www.screwfix.com/p/no-nonsense-ptfe-tape-pack-of-10/51030

Yes I wrapped it around the threads so none will be in the oil system, but I've read it's not oil-proof so was looking for an oil proof sealant recommendation

[mowgli]

If there is a bsp or jic thread, they are designed so that the male & female cones get pulled up so tight that they can't leak on the cones, the threads are not what seals.

If you are winding a male thread into a block, you need a copper washer or better still, a dowty washer (it has a rubber seal built in) between the union & the block. Again, tightness is the key.

Ptfe tape is nasty crap & oil never seems to like it

[Iain]

Duh good call Mowgli, yes I can see the cone that seals up. So it's probably the male into the sandwich plate. It has a copper washer on however it's a slightly larger OD than the original washer so may not be sealing correctly against the slightly corroded face. I've cleaned it up a bit so I'll refit it with some sealant on the threads and hope for the best!

[Iain]

Didn't work.. I'll try those dowty washers.