Putting a t fitting to run a mechanical oil pressure gauge and the stock one.

[Colton stephens]

So I’m having issues with my oil pressure sending unit and from research I’ve heard that the stock one isn’t the most reliable. I’ve also heard that putting one at the top of the oil filter housing reads higher pressure than the stock position. Some other people in other post have talked about putting a t fitting in the stock position to run both a mechanical gauge and a stock one. What are y’all’s thought on doing this and how should I go about it? So I put the t right in the block and run the 2 gauges off of that. Or a saw one person said he ran a line away from the block and put a t. What size t do I need and is there a certain material to use, what size line, what material do I use for the line, ETC.

 

[Cummins12V98]

My 98 oil pressure sending unit started to drop to zero when coming to idle with a fully warm engine at around 100k. I changed the sending unit and it's been fine for over 300k. It was a CUMMINS part.

 

[HHhuntitall]

Personally, I'd just change the sending unit.... if you're dead-set on a secondary guage, you can T the sending unit, but it's probably an O-ring fitting coming out of the oil galley... you'll need some fittings to adapt it to pipe thread... then if you want a mechanical guage, you need a pressure snubber; you don't want hot motor oil running into the cab, running down your leg if there's a breach. I'd use the fittings to another pressure sending unit for an electric guage, myself, if I had to run another guage. There's not a lot of room there, so a line may be needed to get the fitting where they'll clear for the sending units.... another reason I'd keep the stock setup....

A reading off the oil galley on the passenger side is usually a bit lower, as it's pumping oil to the rest of the engine, front to back, up and down... The reading off the filter head is higher because it hasn't dispersed at that point. It's not inaccurate, but doesn't reflect oil loss as quickly as the lower side....