DUMB MECHANICAL OIL PRESSURE GAUGE QUESTION

[CFD244]

Hi Folks

Does the 1/8 feed line to an aftermarket mechanical oil pressure gauge need to be primed before connecting it to the gauge or does it get connected dry? In all honesty, I don't ever remember priming one.

Thanks
FABO

 

[70SwingerGuy]

deleted

 

[harrisonm]

I have often thought that, but I have installed several, and they all worked fine without priming.

 

[GTX JOHN]

They do not require priming.

 

[halifaxhops]

USE A COPPER LINE not plastic!

 

[CFD244]

USE A COPPER LINE not plastic!

I always wondered how the solid line deals with engine movement?

 

[abodyjoe]

USE A COPPER LINE not plastic!

i prefer the braided lines.

 

[azaustin]

i prefer the braided lines.

Where do you find braided lines for oil pressure gauges?

 

[halifaxhops]

I always wondered how the solid line deals with engine movement?

I put a safety loop in the engine compartment to handle that. I have had a few plastic lines fail inside the pass compartment, usually not pretty. Now all I use are the ones with a sensor wires and gauge.

 

[abodyjoe]

Where do you find braided lines for oil pressure gauges?

can get it anywhere.. Summit Racing SUM-G2961 Summit Racing™ Gauge Accessories | Summit Racing

 

[4spdragtop]

Good question Troy, I've never primed/bled the air out. I'm also on year 13 of using plastic with our mech. gauge.
Personal choice.

I always wondered how the solid line deals with engine movement?

 

[Kendog 170]

I too had plastic for years without an issue but went to copper with a loop like Halfaxhops does on my last build.

 

[azaustin]

I’ve had plastic lines break under the dash as noted in someone else’s post. Pretty nasty. The copper loop is a good trick, but I’m going to go with the braided SS lines. They look good, and you can get various lengths to fit your needs (thanks abodyjoe!)

 

[Hellrats]

I had a plastic line break and spray hot oil all over my leg. Never again. Mine is an electric gauge from now on.

 

[Scody21]

Where do you find braided lines for oil pressure gauges?

Summit. Use AN-3 hose and the fittings that go with it. Will have to get gauge adapters

 

[Oldmanmopar]

Good Braided is the smartest way to go (Fragola) . Copper cracks off at the fitting and plastic fails after sitting against things when hot. Nothing worse then a spray down in the car while driving. Just think about it. 60-80 psi. Oil spraying everywhere ! . Why take chances?

 

[GTX JOHN]

I always wondered how the solid line deals with engine movement?

Never had an issue but no reason you could not put a loop
in the line for movement.

NHRA requires a solid or braided steel line = NO Plastic stuff.

 

[SSG_Karg]

Summit. Use AN-3 hose and the fittings that go with it. Will have to get gauge adapters

Got a link for the gauge adapters? I have the braided line on the shelf but have never been able to find an adapter that would work with my gauge.

 

[MechNerd]

If you're concerned about air, you can do a quick bleed behind the gauge. Warm up the oil and crack the brass nut until you don't see air (plastic lines). You might get a few drips, but keep a rag under the gauge and you should be good.

 

[Scody21]

Got a link for the gauge adapters? I have the braided line on the shelf but have never been able to find an adapter that would work with my gauge.

https://www.holley.com/products/plumbing_an_fittings_and_hose/adapters/gauge_adapters_and_fittings/parts/968603ERL

 

[RustyRatRod]

All I have ever run is the plastic (nylon) and never had an issue. We even used it on the track and no one ever said a word. I always run it along the wiring harness and zip tie it every few inches. I keep it away from anything hot and sharp. I have however, seen copper line break and it had more than one loop in it. If you don't want the nylon line then I would go with braided.

 

[CFD244]

All I have ever run is the plastic (nylon) and never had an issue. We even used it on the track and no one ever said a word. I always run it along the wiring harness and zip tie it every few inches. I keep it away from anything hot and sharp. I have however, seen copper line break and it had more than one loop in it. If you don't want the nylon line then I would go with braided.

I was going to run the nylon, but some of the previous posts have me second guessing that. Once the compression nut is lightly seated, how much additional tightening torque is required to secure it without pinching the line.....1/4-1/2 or more?

 

[RustyRatRod]

I was going to run the nylon, but some of the previous posts have me second guessing that. Once the compression nut is lightly seated, how much additional tightening torque is required to secure it without pinching the line.....1/4-1/2 or more?

I probably go down 1 full turn. Possibly more. I seat the piss out of it. Never had an issue.

 

[1971 CY Dodge Dart]

I used a plastic line when I installed my oil pressure gauge a few years ago but switched to a braided line shortly after. With the plastic line the gauge worked fine. After switching to the braided line my gauge bounces around all the time now and doesn’t give a solid reading. Anyone have an idea why?

 

[Scody21]

I used a plastic line when I installed my oil pressure gauge a few years ago but switched to a braided line shortly after. With the plastic line the gauge worked fine. After switching to the braided line my gauge bounces around all the time now and doesn’t give a solid reading. Anyone have an idea why?

It could be that the hose is leaking at one of the fittings, for -3 and -4 there should be olives in the fitting. We pressure test all of the braided hoses we assemble. We use -3 for brake lines on the race cars and once in a while we have an issue with the olive not sealing right.