Pressurized gas tank

[Vintage Boat Guy]

I've been refurbishing a few pressurized gas tanks and I was working on one from the early 50's. It pumps fuel fine and the rubbers are in good shape but when it gets pressure in it I get fuel on my finger as it comes out by the botton. Why is this happening? Photo is of the tank I was working on.

 

[Scott Danforth]

because the tank is rusty and has holes in it

 

[Vintage Boat Guy]

Tank has no holes its coming out up the plunger shaft

 

[F_R]

Poor sealing where the primer push rod goes through the diaphragm. There are a few requirements.

Diaphragm support washers should be flat in their center (they will deform when you tighten the nut)
Diaphragm support washers should not be rusted where they contact the push rod.
Bottom end of the push rod should be flat where it contacts the support washer.
You should put a small dab of fuel proof sealer on the end of the push rod where it contacts the support washer.

I see your push button is missing. But if present, it should spin freely on the push rod. This is to prevent unintentional rotating the push rod and unscrewing the nut off the bottom.

 

[jimmbo]

 

[JimS123]

When I refurbish tanks I buy the entire "kit" that replaces all rubber parts and gaskets. I would guess you have a bad o-ring on the shaft.

 

[jimmbo]

I tried posting this earlier, but... Blasted iphone

This is the oldest tank I could find, but your tank looks even older

I would suspect a tear/hole in the diaphragm. It doesn't look like there is any o-ring or seal on the shaft