Oil Gauge Sending Unit Install

[JBeau]

While my car was not running over the summer (see other thread, issue now is solved), I decided to replace the broken clock with an oil pressure gauge that I had picked up a while ago. I got an "oil pressure port doubler" from Midwest-Bayless and managed to get both sending units installed and wired correctly. For those that are not familiar, this threads into the port for the oil light sender and allows for the installation of the sending unit for the gauge alongside.

The issue I am having is that whatever I try, I cannot get the whole assembly to stop leaking oil! The gauge sending unit is fine (I have it attached to the "Y" of the doubler), but I am losing oil from either the oil light sender or one of the two spots where the port doubler passes through the "Y" or threads into the engine above the filter. I have new crush washers at all locations and have everything fairly tight. I have the light sender attached to the end of the extension (sorry, I don't really know how to describe these parts well), since I thought that if there was a sudden drop in pressure that caused it to come on, it would be more accurate there. That location also allows me to install it off the car with a 21mm wrench and socket and install the whole assembly together.

Is there something I should be doing other than tightening the bejeezus out of this? I don't want to break or strip anything, and I am not sure how I can get things any tighter than I have them, since I don't think there's space for an impact. I have also added ptfe thread sealant as well when I installed everything as an additional measure of protection.

As always, thanks in advance for any advice you can provide!

[18Fiatsandcounting]

With new crush washers on the sending units, you shouldn't have to tighten the beejezus out of it. 20 ft lbs, even with your calibrated wrist, should be fine. I know you said that you had new sending units, but are these leaking out the end by any chance? I've seen relatively new units still leak at the terminal where the wire connects.

Don't use an impact wrench. Doesn't need to be THAT tight....

-Bryan