I need to put in a new oil pressure sender, I though I remember that it wouldn't work properly if you used teflon tape on the threads. Is this true? Do you install this dry?

Kev

Install it dry.

Tapered threads, no sealent needed.

The general consensus here seems to be not to use tape (or lubricant) I really don't understand why not. Tape is not a sealant. It is to prevent the threads from galling allowing it to tighten tighter. Why is this any different from tapered threads in plumbing? There you will use a Teflon tape or pipe dope of some kind. All of these are thread lubricants.

I put case sealant on it just like all the other pipe-threaded plugs I installed on my engine.

Teflon tape is bad because it degrades with fuel or oil or continued heat, and can permit a leak.

Zach

That sounds more like it!

I believe the sender needs to ground to the case to operate correctly.

The sender has to ground to the case. I have the relocation kit so I used teflon pipe sealant and grounded the sender separately.

The sender needs to ground, so both sealant and tape cause problems. Worse, since they're tapered threads that slick Teflon tape makes it REAL easy to overtighten the fitting so much that you strip the threads. And there's no oversized sender, so it's not feasible to re-tap the threads the next larger size. More in magnesium cases, but still a serious bummer.

I use a small amount of permatex aircraft sealant. They are tapered threads (dimensionally the same as 1/4" NPT) so in theory they should seal when you tighten them, the problem is when the bore has had a sender over tightened.

when using a remote setup for a guage/idiot light....can you pleast post some pics of how you "grounded" the sensor.
I have done it, but I am hoping to see a more elegant solution.

Rich

Mark is 100% correct. It's a lubricant. So is a bar of soap. Get your mind out of the gutter! As Mark mentioned; pipe threads are tapered. (Know the ratio? It's 1" per 12ft.) The dope, tape or any other lubricant just allows the tapered threads to perform their original function with less resistance. Teflon differs from other types of lubs in that it can be used as a sealant. When there is a leak at a tapered thread joint, it is a funtion of the threads; not the pipe dope. Pipe dope will not seal "shit". However, with enough teflon tape applied, threaded diameters can be increased in size. This is where Teflon tape gets a bum rap. Anything, I repeat anything is dangerous in the hands of the ignorant. Notice I didn't say idiot. There are specific tapes designed for certain jobs and they are color coded. Pink is for gas. Also, the good stuff is thick. Not like that cheap stuff you find in hardware stores. And because it is gauged you know to use no more than 3 1/2 wraps! Do you know where to begin wrapping? At the starting threads. And don't put it on backwards. Yes, it matters. Clockwise, the same direction as the threads. Do it the other way and......."Oh my gosh. What happened to the tape. It came off!" As far as heat being a problem; I literally solder and braze (700F-1100F) within 1-2 inches of teflon tape threaded joints (and have done so for 30 yr's) with no resulting leaks. (remember the tape has already completed it's job at this point.) I wouldn't hesitate to used it any auto application; or Permatex A/C sealant or a bar of soap or a drop of oil (except on PVC, oil or petroleum based pipe dopes will soften PVC) Life is like a box of chocolates. Thats about all I have to say.

I believe in every rebuild kit there is a crush casket that is to be used between the oil pressure sender and the case. Please correct me if I'm wrong. Al

Mine worked with case sealant. I am using a paintball hose to remote locate a dual sender for the idiot light and the VDO pressure gauge. it is grounded to the case via the mount, which bolts to the case.

Works like a charm.

Zach

I used a grease gun hose. Someone (maybe Krusty ) gave me the idea on here. Works like a charm. I then used a conduit strap to hold the sender down. Looks ok. Better than the hose clamp thing I think. Total cost was like 12 bucks vs the 40-50 for the VDO one.