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Hi all. Just plumbed in an external oil cooler (in addition to the stock one) for my Type 1 2276 in my Bus and need some help. I have 2 leaks:

1. Leak from cooling fan switch in an in line fitting (lines are all AN 8 braided with an in-line straight fitting on the cooler outlet with 1/8 NPT port for switch)

2. Oil pressure switch (leaks from T fitting with oil pressure sender)

The leaks are not significant however, they are leaks and I want to deal with them properly.

I am loathe to use PTFE in these locations, being oil lines so I wondered what you guys think is best to use for stopping these leaks. I have on the shelf - Locktite 609, Gaskacinch, PTFE (though would rather not use this) .

Any thoughts please?

Thanks

Rich

1. NPT to NPT really anything should work w/o drama, nascar seems to like jb-weld myself I have not tried this. Low risk whatever is closest

2. Straight thread? I am confused on what you have mixing tapered SAE w/tapered metric (they as with NPT BSPT looks the same from a distance). Normally cases are metric M10 tapered if you have ignored that minor detail I would be tempted to try loctite 518 or 515. This is higher risk as you are mixing standards

I haven't mixed anything size wise...

All of my oil lines to cooler are AN8 BUT the port for the fan switch is 1/8 NPT.

For the pressure switch, I have a straight fitting from the port on the case into a T and it is at the T into the pressure sender where it is leaking - not at the case

Thread tape or liquid sealent are required on NPT fittings otherwise they tend to leak due to the design.
Good Luck
Kenric

We use Teflon pipe thread tape on our NPT fittings and it works for us. I do not recommend JB Weld unless the threads are damaged somehow.

Aviation Permatex works as well.

The main warning is not to make the rookie mistake of applying tape or sealant to your electrical oil pressure sensor threads -- they won't ground.

I've had good luck with Permatex high performance thread sealant as well over the years on NPT fittings, not AN/JIC

Tom

FJCamper wrote: ↑Wed Jun 03, 2020 9:33 am The main warning is not to make the rookie mistake of applying tape or sealant to your electrical oil pressure sensor threads -- they won't ground.

One of the main things one has to think about. Very good point FJ.

Lee

For anything oil - locktite blue. Super clean fittings with final acetone wipe, then a bit of locktite on the threads. Won't affect ground connection and once cured won't leak (or vibrate loose). Easy to disassemble if necessary, just need to lightly run an NPT tap in to clean up the residue and wire brush the external fitting, re-clean and re-assemble. Good for brake line NPT fittings too.
Jeff

Cheers for the replies fellas and - sorry it's taken me this long to actually get back to this - havent been able to get to work on the bus much where it is stored with all the virus restrictions! Ended up removing the damn t piece from the case and went with a stock switch with a light smear of Permatex thread seal. Same for the oil lines fittings at the cooler thermostat. All good now.