My new oil pressure switch continues to allow oil by, dripping on my heat exchangers and smelling awful.

I finally got around to looking at the old parts diagrams and noticed that a sealing ring (Pelican part 900-123-007-30-M131) should be there. Does anyone know if this 25-cent part is something that is available at my local autoparts store or what material it is supposed to be made of? What are you using to seal the sender?

I hate to order a 25-cent part and have it shipped and really need to get this leak sealed up as I'm blowign a lot of oil through the leak and my wife is asking to get the car out of the garage due to the smell...

Oil pressure is on top of the engine, you are looking at the oil temp switch located in the toco plate on the bottom. Not sure about the seal, is it an o-ring or copper ring.

Good catch on the drawing!

My Switch is leaking at the top and am wondering what is good to seal it up...

Goto your local automotive store and by a 10 mm ID round gasket. Same
as the one used on brakes.

Whoa!!!!!!!!!!! STOP RIGHT THERE!!!!!!!!!!!!!!! The oil pressure switch has a tapered thread, and uses NO sealing ring. The hole is actually some weird 10mm tapered thread, but the switches aren't. Tapered threads are self sealing, and a gasket actually prevents the switch from tightening up on the threads. There are switches with gaskets, but they don't have tapered threads. If you have one of those, it's for a different application, and may not have the correct range for the system. If your OP switch still leaks when tightened properly, you may need to clean the hole and the switch, then apply some teflon sealant, sold in tubes in the plumbing section of your favorite hardware store. NOT TAPE! A more common solution is to simply replace the leaking switch, because the switch itself commonly fails by leaking between the metal parts and the plastic. Be sure to use an OE replacement so you can install it with a 24mm socket instead of water pump pliers, and so the range is correct. The Cap'n

Thanks Capn!

I'll try the tube sealant. I'll be at the Home Depot tomorrow for other stuff...

BTW: My switch is OEM and is as you describe. When I had my engine rebuilt, we noticed it then. We thought it was an old switch seperating and I later repalced it. Still the smae results. Maybe the PO overtightened it or something...

Its not tapered, its a 10 mm x 1 thread ,not a 1/4 28 tpi (its close to 10mm x1)thats why people are having problems cracking the case when they tighten it