Oil Gauge Install Questions

[RT66DOC]

My truck---> '96 12v, 5sp, 4x4, w/lousy factory oil pressure gauge. Took it to Cummins SW in Albuquerque where they put a mechanical gauge on it. At idle: factory gauge-36 lb, mechanical test gauge (accurate to +/- 1 lb. ) - 58 lbs. They said it's probably a bad sender. Drives me nuts... after the oil is hot, the stock pressure gauge is all over the place - flicks back and forth between 0 and 45 depending where your right foot is. Anyway, I would like to run a mechanical oil pressure gauge out of the port on top of the oil filter housing (the one next to the turbo oil feed line).



Does anybody know the thread size of the plug in the top of the oil filter housing? It would be nice to know what size fitting to get before I go shopping.



Also, where's the best place to hook up the gauge light so the brightness is controlled by the dash light dimmer on a '96?



TIA/Cheers



Tom

 

[illflem]

The filter port is 1/8" NPT, the same size that comes with most gauge tubing kits. The problem with using this port is that in order to get in the cab by the shortest route you have to run by the very hot turbo/exhaust manifold area. You should use copper tubing for this area, something I don't like in a diesel because the vibration tends to flex the tubing till it breaks. Nylon tubing works great but you have route it around the hot spots, no big deal except that most tubing kits don't give you enough tubing, you need to buy it in bulk. Napa sells high quality tubing by the foot for cheap though. You might be better off to use nylon from the stock sender location. It will be more out of the way and can follow the factory wiring. The sender port is also 1/8, but you will need a sender socket to remove your faulty one, about $10 from most auto parts. Sure you don't just want to buy a new sender? If you do the Dodge sender is best but more expensive, folks have had cheaper aftermarket senders fail rapidly.



The dimmer circuit under dash 12v+ is the tan wire, you can find it in many places from behind the light switch to the stereo area. I've found the easiest place to tap in is in the wire bundle about a foot to the left of the stereo.

 

[Tim1]

Hey Tom, I used a length of grease hose to get to the firewall, then I used copper tubing to go to the guage. Don't use the plastic stuff, it leaks! Plastic has its place, but not here.

Tie the grease hose up with ties, works great. Tim

 

[illflem]

I have to disagree about the nylon tubing leaking. Copper tubing hasn't been used on OEM mechanical pressure gauges since the late '50s for good reason, nylons better.

 

[RT66DOC]

Thanks for the replies, guys.



I'm thinking of using a VDO (Cockpit Series) gauge - seems to match the stock ones. I found them for a pretty decent price on egauges.com - <$30 as I recall. They also have kevlar tubing kits with AN fittings - different lengths and verrry pricey, but they look trick. Whaddya think of kevlar vs nylon???



Cheers

 

[illflem]

Never used kevlar but it sounds strong. Are you going to install the new gauge in the stock oil pressure gauge location?

 

[RT66DOC]

I thought I'd put the new gauge in one of those single gauge mounts that replaces the top of the steering column cover - see last edition Geno's Garage catalog. Maybe I'll just paste a NRA sticker over that old oil gauge.



Besides kevlar, egauge also has braided stainless plumbing for mechanical gauges. Any opinions on that?