gas tank pressure pump

[AHa]

Can someone describe to me how to install a gas tank pressure pump? On this pump, there was a ball bearing in the bottom connection (I dumped it out on the ground and lost it).

 

 

Edited June 17, 2022 by AHa (see edit history)

[1912Staver]

It just connects to the top of the gas tank, above fuel level. It is a good idea to place a T fitting in the line and install a pressure gauge on the dash . A few pounds pressure is good, but you don't want to over pressure the system. Some of the better ones have a built in pressure limiter, but most just rely on the driver keeping an eye on the gauge. Yours looks like it already has a T, one branch to the tank, the other to the gauge.

Edited June 17, 2022 by 1912Staver (see edit history)

[AHa]

I have heard you need a check valve in the line, is this incorrect? My gas tank does not have a provision for a line to the top of the tank, can I not plumb the pump into the gas line?

[Mark Gregush]

Many would have been installed in the dash or mounted to side of seat so you could add pressure to the tank as needed. Guessing should have that ball check valve to prevent fuel from back flowing into pump. For the early Dodge setup as an example, there would be two lines, one for fuel to carb the other to pump up the tank. If your tank does not have a 2ed line, could be the fuel cap had the fitting?What are you putting it on? How new? 

[alsfarms]

My system has a ball type check valve in it to stop you from pulling pressure from the tank when you pull out the handle, then when you push in the handle the pressure pushes the ball off the seat and allows one way pressure to go to the tank and pressure gauge from the pump.  Hope this helps.

Edited June 18, 2022 by alsfarms
clarity (see edit history)

[1912Staver]

Any factory ones I have seen are connected to the top of the tank. In theory I guess you could T into the liquid filled fuel line, but I think that would tend to introduce air into engine side of the fuel line, possibly starving the engine for fuel. Probably safer to solder a female threadrd boss to the top of the tank like factorys did.

[roysboystoys]

I read a mention of a pump with two lines. Any readers here know what this fits?

I've had it for sale for awhile , but it would help to know the application.

I also have a single line pump I posted photos of , I don't know it's application either.

Thet look like dash mounted pieces.

Thanks for any help.

[hidden_hunter]

Here’s how it’s setup in the early 20’s Cadillacs 

[Rusty_OToole]

The ball bearing you lost is the one way valve, you probably figured that out by now.. You have to have it for the pump to work. Any bearing supply place will have a bucket full of them, or you may already have one in the form of a bicycle bearing or the like.

Early cars and race cars that had pressure systems had heavier gas tanks to hold the pressure, and then they only used 2 or 3 pounds of pressure. Once you pump up the air pressure it will hold for a long time you don't have to keep pumping it up. The more air space on top of the gas the longer it will last.

Royboy are you sure that isn't an oil pump? Some early cars and motorcycles had them, you gave the motor a shot of oil every few miles.

[Oldtech]

The second one (Roysboystoys) looks like a primer pump like Buicks had - only it's not Buick,  or a Lube pump. Do the threads just lock the pump or do you have to turn it all the way.  If it threads all the way it's a grease or oil pump.

[AHa]

Thanks to everyone who offered help. I think I now understand how this was designed to be used. The bottom connection, that had the ball bearing in it, was designed to go to a pump on the motor, or, an exhaust outlet. The air from one of these two sources would push the ball bearing up where it would continue out the side connection to the gas tank. The pump would be used to pressurize the system to start the car, then the pump on the motor, or exhaust gas pressure, would take over. The ball bearing would be forced down on its seat when the pump was being used and would seal the pressure in the system until the auxilliary source took over.

[1912Staver]

Some did have a air pump on the engine, and the hand pump was just for starting. But others just used the hand pump and the driver had to add more pressure from time to time. I think the ones that used exhaust gas were the least common. My Packard truck has a small air pump driven off the camshaft, but very few other engine I have seen have this feature.

[Mark Shaw]

On 6/17/2022 at 10:12 AM, AHa said:

I have heard you need a check valve in the line, is this incorrect? My gas tank does not have a provision for a line to the top of the tank, can I not plumb the pump into the gas line?

The ball bearing you lost is the ball check valve.  It allows air to exit when the plunger is pushed down, but stops air from entering from the bottom when the plunger is pulled up.  Replacement air enters from the top of the cylinder.

[Mark Shaw]

2 hours ago, 1912Staver said:

I think the ones that used exhaust gas were the least common.

I agree.  Fortunately, early Buick engines had carb heat supplied via exhaust from a threaded port on the exhaust manifold that can be adapted to pressurize the fuel tank.  My 1913 Model 31 manifold heat has been re-routed via copper tubing with an inline spark arrestor to the gas tank filler cap.  The gas cap and vent are sealed and a removable fuel tube is at the end of the exhaust tube to allow removal of the gas cap. 

 

This setup has eliminated the necessity of backing up hills to keep fuel supplied to the carb when the tank is low on fuel.  There are no moving parts, and it is completely safe when exhaust gasses displace the combustable air in the tank.  The spark arrestor functions to prevent combustion with the small amount of air in the tank after re-filling. 

[hidden_hunter]

7 hours ago, 1912Staver said:

 

Some did have a air pump on the engine, and the hand pump was just for starting. But others just used the hand pump and the driver had to add more pressure from time to time. I think the ones that used exhaust gas were the least common. My Packard truck has a small air pump driven off the camshaft, but very few other engine I have seen have this feature.

 

The Cadillacs had a hand pump for starting then an air pump that’s gear driven off the engine. They also had a compressor running off the gear box 

[roysboystoys]

On 6/18/2022 at 7:57 PM, Oldtech said:

The second one (Roysboystoys) looks like a primer pump like Buicks had - only it's not Buick,  or a Lube pump. Do the threads just lock the pump or do you have to turn it all the way.  If it threads all the way it's a grease or oil pump.

Thanks for reply. The threads on the round handled one lock it down, it is released to pump or siphon. looks like the connectors on the end are one intake and one outlet.

The other T handled pump is spring loaded, when you pull back on the tee handle it compresses a spring.

The photo barely shows a second connector on the side of the body , one inlet and one outlet?

The round handled one might be a primer for diesel tractors?

I may have over priced these , but it seems like someone would want them.

I had a Dodge one that was sold quickly.

My earliest car was a 1929 Hudson , so no hand pump , I'm ignorant but learning.

Thanks for the input .

Sorry to hijack the thread , but I got no input on " What's it" when I asked a few months ago.

 

Edited June 20, 2022 by roysboystoys (see edit history)

[RAH]

Guys, Also consider the volume of air space will affect the pressure. On my '15 Dodge Brothers I do NOT completely fill the tank with fuel (round tank) as the volume of air decreases rapidly initially as the fuel in the round tank goes down. Also, if the tank is filled to the top it will have a tendency to pull fuel back the air line and that ball check on the hand pump may allow fuel to dribble down the dash and floor. Don't ask how I know that! Actually it was a faulty leather seal on the pump handle inside the pump. Just saying Volume and Pressure are interconnected.