Oil Pressure with the Sending Unit

[Lynn Kirkpatrick]

Does anyone know how the oil pressure sending unit and gauge work?

My '68 BGT shows reasonable pressure at startup. But after warming up it reads low. I T-ed in a real pressure gauge connected to the same fitting on the block and the pressure is OK.

So what can I check at the gauge and the sending unit to see where the fault is? The sending units are $100+, and the gauges aren't available. If the gauge is faulty, does anyone repair them?
Thanks

 

[PAUL161]

Lynn, Before going off the deep end, see if you can borrow an old sending unit from someone and try it on your car. If it reacts exactly the same, then I would assume the gage needs rebuilding, if it doesn't, then your sender needs replacing.
And to answer your question, yes there are re builders for gages. PJ

 

[PAUL161]

Lynn, I never gave it a thought but, Advance Auto Parts sells Beck Arnley oil pressure sending units for under 20 bucks. Don't know if they'll work on a B gage, but for 20 bucks it's worth checking out. They come with various wire connectors, spade lug, button etc. Check out their web site also. PJ

Will a later model mechanical gage work?

 

[PAUL161]

Me again, I just heard that the new ones don't last very long. Evidentially their poorly made and very expensive. A suggestion came out of this conversation, that you should try and get one from a later car that had the electric gage. I think the 79 I had, had one. Can't remember for sure. It's a CRS thing! PJ

 

[Lynn Kirkpatrick]

Paul, I had tried to get the sending unit at Advanced. The local guys only had an oil pressure SWITCH. They could try to match up the fitting size and pressure range, but I think I'll try your idea of looking for a later year. Thanks