Oil Pressure Gauge (accessory)

[Charles Reese]

when the accessory oil pressure gauge is used, what is the usual routing of the copper tubing from the block to gauge?

[James Rogers]

Charles, I route the line around the back of the block and just under the throttle assembly and up the steering shaft to the gauge. Mine is mounted in the dual mount that straddles the column under the wheel. Make sure you use copper line, the plastic line will get into the exhaust and melt at just the wrong time.

[Dennis L Oberer]

Mine is the same as James Rogers installation.

Dont use a gauge that measure more than 10 pounds or the needle wont even move.

My experience on a conventional A engine is that you get about 6-8 pounds when the 30 weight oil is cold and stiff and then down to 0-2 pounds when the oil is warm and thinner.

The A is a volume not a pressure pump. Take out that inspection plug that is on all A blocks in the area just below the centerline of the valve cover and you can pump out the oil pan of an A in about 2 minutes with it at idle.

All the oil pump does is take the oil up to the valve chamber where it drains down to the mains and the timing gear. Some works its way up to the distributor but not often.

IMHO

Dennis L Oberer
Green Bay WI

[TomW]

The gauge on my truck (installed over 50 yrs ago) is mounted just under the speedometer. The line runs straight back from the gauge along the under side of the wiring conduit for the instruments (visible if you lean down and look) and then goes out through the terminal box to the engine compartment where it runs over and down between the choke rod and the manifold to the block.

[Glenn C.]

Charles the recomendation of James is correct, other than a person should also slide the copper tubing through a length of braided loom to prevent wear, and possibly tie it back using very small black tie-wraps under the throttle linkage.

[rob mcdonald]

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I have used plastic tubing and brass fittings on the three A's I have owned. The current 30 coupe is routed to the gas line up to and through the vacuum brass fitting close to the sediment bowl then across the inside gas line to a dual gauge under the speedometer. I use two wire ties on the gas line and the line cannot get close to the manifold. Depending on where you route the tubing I would go by James' advise and use copper if routed close to heat. However the first installation I used plastic was in 1999 and it is still intact.

[B0B]

I had an oil pressure gauge in my Model A with the plastic tubing ...The tubing broke off right behind the gauge and I had oil running all over the front floormat area and me too! I have an oil pressure gauge in the Model A I have now BUT I bought adapters at the auto store for each end of the tubing that adapt to STEEL 3/16ths inch hydraulic brake line it works great ! A 4 foot section is just the right length ...B0B in Michigan

[pooch]

Does the gauge plug into the inspection plug?

[Stillrunners]

yes...could someone show where an oil gauge could be can/should be installed?

thanks

[spinelll]

This is how my line is routed. It's highlited in red.

[josh1331]

ISN'T THERE A BETTER BRAIDED LINE THAT SELLS IN SOME AUTO SUPPLIERS MAGAZINES THAT WOULD BETTER? i SAW ONE AND WOULDN'T THAT PROVIDE A SAFE PASSAGE AS COPPER BREAKS AND OIL WOULD LEAK ALL OVER i THINK. iM THINKING OF PUTTING ONE IN ALSO BE TIMID ON COPPER?? ANY SUGGESTIONS/JOSH

[Special Coupe Frank]

Originally Posted by Charles Reese

when the accessory oil pressure gauge is used, what is the usual routing of the copper tubing from the block to gauge?

I hate to be a pest, but why is the needle not pointing to "0", with the gauge not-installed, and no pressure on it ?

[josh1331]

Bob: On the 3/16 hyd line for oil pressure, what size fittings are nec/?
Josh

[rob mcdonald]

Originally Posted by josh1331

Bob: On the 3/16 hyd line for oil pressure, what size fittings are nec/?
Josh

You are after 1/8 tubing plastic or copper with brass fittings. Go to Brattons online catalog and the photo shows exactly what you need. Also it is a less expensive cost than to try to find this size tubing locally. The ferrules are both plastic and brass. The pressure is maybe two pounds when the oil is hot and max of 10 pounds when cold. The only breakage is from over tightening these small fittings with brass or plastic. This is finesse touch. You lightly tighten and if you have a small leak you barely move the fitting 10 degrees out of 360 per snugging up.

[MikeK]

Originally Posted by B0B

I had an oil pressure gauge in my Model A with the plastic tubing ...The tubing broke off right behind the gauge and I had oil running all over the front floormat area and me too! I have an oil pressure gauge in the Model A I have now BUT I bought adapters at the auto store for each end of the tubing that adapt to STEEL 3/16ths inch hydraulic brake line it works great ! A 4 foot section is just the right length ...B0B in Michigan

Steel line is great, but 3/16 is way overkill. 0.060 steel cap tubing is plenty. I have always used flow restrictors on remote pressure gauge apps, they will reduce a major flood to a dribble if the line breaks. You attach it at the source, so you need a 1/8 male x female pipe thread restrictor. One with a 0.018 hole is plenty. They're cheap- less than $10 in brass, about $14 in stainless. LINK- Flow Restrictors

[Charles Reese]

Originally Posted by Special Coupe Frank

I hate to be a pest, but why is the needle not pointing to "0", with the gauge not-installed, and no pressure on it ?

never a pest! good eagle eye!! i had not noticed and do not plan on using but was interested in its installation. would need some calibration in order to use

[Special Coupe Frank]

FWIW on the "copper vs plastic" discussion...

Years ago, I had a '61 Willys 4WD pick-up, that now belongs to a good friend...

Anyway, the original owner fitted it with a Stewart-Warner mechanical oil pressure gauge, that was originally plumbed with plastic tubing. The oil pressure tapping was on the same side of the block as the exhaust.

One night, as I was driving, I smelled hot oil, and noticed there was no pressure on the gauge... the plastic tubing had melted.

I went to the local auto store, and purchased a gauge installation kit with copper tubing, and threw the plastic away.

The copper has held-up fine for twenty some years ( the truck is still in service ).

I prefer metal lines. Plus, they look more appropriate on an older vehicle.

Good luck !

SC Frank

[rob mcdonald]

I sincerely believe some are over reacting to plastic tubing leaking, melting, breaking or whatever. Also on a model A you do not need a flow restrictor because you have very low flow. If I have a leak I want to know.
The photo provided above shows a safe location for installation. I spent my working life in the plastics industry. I hope this helps....

[MikeK]

Originally Posted by rob mcdonald

I sincerely believe some are over reacting to plastic tubing leaking, melting, breaking or whatever. Also on a model A you do not need a flow restrictor because you have very low flow. If I have a leak I want to know.
The photo provided above shows a safe location for installation. I spent my working life in the plastics industry. I hope this helps....

Go for a drive with a broken oil line from your Model A dumping inside the car. If the line breaks or disconnects behind the gauge, even at 2 psi you will quickly have a big mess. A model A pump is low pressure because there is little output restriction, but it is NOT low flow. I too want to know if I have a leak, but a few drops are sufficient evidence. I don't need a pint to tell. Also, if the line breaks at the block without a restrictor, you may lose several quarts in an hour's drive. Since you worked in the plastics industry, perhaps you could recommended a specific type of strain-relief fitting to prevent vibration failure, and what type of nylon tubing? Type H, T, ?? Something else?

[rob mcdonald]

There are five main classes of nylon: 6/6, Nylon 6, Nylon 6/12, Nylon 11, and Nylon 12. My guess is Nylon 11 extra flex extruded tubing because it has high chemical resistance properties and a long molecular chain when extruded for strength and flexibility.
Also Nylon 11 is also much less rigid than the type 6s of the resin. It allows for a lighter weight tube wall, greater flexibility and smaller bend radius.

There is a reason nylon is used for high strength fishing line, ropes, brush fibers for street cleaners, to tooth brushes, molded trigger springs for power tools and flexible tubing because these items are resistant to breakage after flex testing of millions of cycles.

The tubing also maybe polyethylene as it is the base material used in the red gas jugs you buy for your lawn mower and in the modern cars that have been using plastic gas tanks in place of the traditional steel. Polyethylene is also used in rope, the PEX hose for use in homes that will not break when full of water and frozen or when used with maximum temp for water heaters and heaters of homes via tubing in floors.

Another formulation of PE is used in the trash bag industry where the higher quality formulations are difficult to break even after stretching 10x1.

There are so many formulas of these base plastics that I can only guess which is the one being used

None of the quality formulations for tubing require strain relief fittings. Plastics is often miss used and therefore must be correctly applied. The materials coming from the Far East are some times of poor quality and poorly identified as to application.

If you are interested in knowing the actually plastic being used ask the suppliers: Mikes, Bratton’s, Snyder’s, Mac's and others what plastic tubing they are selling for this application.

Or buy the copper line that is rugged yet subject to stress hardening if not properly supported to dampen vibration.

The model A oil pump has a high volume but as the oil heats up the pressure drops to very little depending on where measured. If measured at the discharge close to the pump the pressure may be only 5 PSI when hot but only 1-2 PSI at the gauge mounted under the speedometer. When located on the top of the steering column the pressure may be zero.

Fact; with the flood oiling system the gauge PSI will diminish due to the length of the tubing, and the height of the gauge above the engine.