Added an oil pressure gauge and kept warning light

[Bighorn]

I added an oil pressure gauge to my M1009 and plumbed it into a tee so I can still have a functioning low oil pressure warning light.
Things got a little kooky when I discovered the oil switch is threaded 1/8-27 npt and NOT the 1/4 npt I thought.
Turns out the 6.2 block actually has a 45 degree fitting threaded into the oil passage under the oil switch.
That fitting is 1/4 x 18 male thread where it goes into the block and 1/8 x 27 female thread where the oil pressure switch goes.

I bought a 1/4 x 18 brass tee and a 1/4 nipple.
Lucky for me the gauge came with a bushing that adapted it to fit the 1/4 x 18 tee.

A little re-work of my plan and I have an oil light and pressure gauge.

I know, it should match my volt meter in color.. I like the white gauges better.

View attachment 699845
Here is the crazy 45 degree fitting that was threaded into the block of my 6.2. Note; It is 1/4 - 18 male where it goes into block and 1/8 - 27 female where the warning light went.
This necessitated a re-work of how I planned to put things together but achieved the same result.

View attachment 699844
Here is how it ultimately went together.
That tool at the bottom is my well worn Basin wrench. You can find them in the plumbing aisle. Mine has 25 years of plumbing work on it but was just the tool to remove the stock oil pressure switch. That and some PB blaster.

View attachment 699846
Installed and working. Yes, I used teflon tape knowing full well that the switch uses the block connection to ground to illuminate the idiot light. Call me an idiot, but the pipe threads make more than enough contact slicing through the teflon tape to make contact.

View attachment 699847
CUCVRUS would never approve!
I know there is a slight difference in color between the oil pressure gauge and stock 28 volt gauge on the right.
Sue me.
(All in fun my friend.. still looking for those WYO plates for you)
I like white backed gauges.
All that was left was to tap into the dash light wires to light up the gauge.
Oh yea, make sure to test everything out by running the engine to check for leaks before you close up the dash.
I routed the oil line to the gauge around the big wire harness and through the speedometer cable grommet.
Wanted it to always be visible for inspection in case of leaks.

 

[Ilikemtb999]

Looks good. Did you use the typical plastic tube that comes with gauges? I'd just keep an eye on that or replace with braided line.

 

[Bighorn]

Looks good. Did you use the typical plastic tube that comes with gauges? I'd just keep an eye on that or replace with braided line.

I used the plastic tube.
But you are right, it will get swapped out at some point with braided line.
On the plus side, that Fluidampr harmonic balancer has taken all the shake out of the belts and motor when at idle.
That, and I seem to have 40 psi of oil pressure at idle but it had only been running 10 minutes.
I'll be watching to see what it is after the 10% grade climb back from town next time I do the shopping.

 

[Rustyshackelford]

When I did mine I bought the upgraded copper tube and man it leaked so much at the gauge. I redid the fitting 4 times before I got sick of having oil all over my cab so I switched to an electric gauge.

 

[Bighorn]

When I did mine I bought the upgraded copper tube and man it leaked so much at the gauge. I redid the fitting 4 times before I got sick of having oil all over my cab so I switched to an electric gauge.

The only way copper or rigid metal tubing will be durable is if it were bolted down tight.
The problem comes between the engine and cab.
Vibration and flex will eventually crack the tubing without some form of flexible joint.
Stainless flex line is really just plastic or rubber tubing with a case of stainess abrasion protection.
As a plumber Ive seen many kitchen leaks where someone's water filter system had soft copper tubing fatigue and crack because an undercounter garbage can or the cabinet door hit the tubing constantly.
Plastic tubing solves most vibration and fatigue issues but is vulnerable to heat.

 

[ridenby]

I added an oil pressure gauge to my M1009 and plumbed it into a tee so I can still have a functioning low oil pressure warning light.
Things got a little kooky when I discovered the oil switch is threaded 1/8-27 npt and NOT the 1/4 npt I thought.
Turns out the 6.2 block actually has a 45 degree fitting threaded into the oil passage under the oil switch.
That fitting is 1/4 x 18 male thread where it goes into the block and 1/8 x 27 female thread where the oil pressure switch goes.

I bought a 1/4 x 18 brass tee and a 1/4 nipple.
Lucky for me the gauge came with a bushing that adapted it to fit the 1/4 x 18 tee.

A little re-work of my plan and I have an oil light and pressure gauge.

I know, it should match my volt meter in color.. I like the white gauges better.

View attachment 699845
Here is the crazy 45 degree fitting that was threaded into the block of my 6.2. Note; It is 1/4 - 18 male where it goes into block and 1/8 - 27 female where the warning light went.
This necessitated a re-work of how I planned to put things together but achieved the same result.

View attachment 699844
Here is how it ultimately went together.
That tool at the bottom is my well worn Basin wrench. You can find them in the plumbing aisle. Mine has 25 years of plumbing work on it but was just the tool to remove the stock oil pressure switch. That and some PB blaster.

View attachment 699846
Installed and working. Yes, I used teflon tape knowing full well that the switch uses the block connection to ground to illuminate the idiot light. Call me an idiot, but the pipe threads make more than enough contact slicing through the teflon tape to make contact.

View attachment 699847
CUCVRUS would never approve!
I know there is a slight difference in color between the oil pressure gauge and stock 28 volt gauge on the right.
Sue me.
(All in fun my friend.. still looking for those WYO plates for you)
I like white backed gauges.
All that was left was to tap into the dash light wires to light up the gauge.
Oh yea, make sure to test everything out by running the engine to check for leaks before you close up the dash.
I routed the oil line to the gauge around the big wire harness and through the speedometer cable grommet.
Wanted it to always be visible for inspection in case of leaks.

Nice. Fix the dang pictures!

 

[M543A2]

Another nice thing to add is a pressure switch that senses oil pressure loss. We put them on our performance cars and other motors with electronic fuel and ignition controls we wish to protect against dropped oil pressure ruining a motor. Summit Racing has Stewart Warner pressure switches in many types. We normally use item #76576 in the Summit inventory. It has a 1/8 pipe thread, male on it. You have to wire a bypass push button to energize the ignition system by bypassing the switch until oil pressure builds up to close the pressure sensor switch, then release the bypass button. We have had problems with valve trains, an adjuster coming loose, that lets a lifter pop out of the bore. the switch will kill the motor before any damage can happen due to the resulting pressure loss. The literature in Summit does not mention it but the ones we have are pressure adjustable via a screw in the top under a rubber cover.

 

[Tinstar]

I just tapped into the oil sample port and it works like a charm.
No delay and no oil in cab.

AutoMeter Setup

 

[ridenby]

View attachment 706791
I just tapped into the oil sample port and it works like a charm.
No delay and no oil in cab.

AutoMeter Setup

My M1028 is not equipped with one of those. Dangit.

 

[Tinstar]

I thought all CUCVs had that oil sample port beside the radiator?

 

[sneekyeye]

If they start to leak, people just remove them.

 

[Tinstar]

If they start to leak, people just remove them.

???

 

[sneekyeye]

Sometimes those sample ports will leak and they'll end up being capped off, or taken off is what I meant

 

[Tinstar]

Sometimes those sample ports will leak and they'll end up being capped off, or taken off is what I meant

Ah
Ok

I have read that also.
Glad it’s there.
Made install super quick and easy.