Pressurized tank leak around pump

[Rick Hessler]

Did full kit rebuild of tank.  Still leaks around the pump.  Leaks a little during initial pump up. I heard that’s normal? Seems to leak a little when the engine is running. Makes the  top of tank wet with fuel. Did I miss something on rebuild of is this normal too?

[Steve D]

Hey Rick, Any leak on these tanks is not normal, meaning if something’s leaking it can be fixed. If yours has the metal push rod, and you say you did a full rebuild of the tank which would include a new diaphragm, then the leak could be coming from the hole in the diaphragm where the 2 cupped washers are and the push rod threads pass through. I borrowed the 1st picture here from one of crosbyman’s posts but your info is at the red arrow.

 

[aquasonic]

The two steel disks, No. 27 in the parts diagram above, can sometimes have rust and scale, but usually can be cleaned up. The side that makes contact with the diaphagm needs to be clean and smooth in order to make a proper seal. The nut and lock washer, No. 33 & 32 need to be snug also, and a drop of locktite on the threads helps keep it from backing off.

The button, No. 25, needs to spin freely on the shaft, No. 26, or over time, depressing the button can actually back off the nut and lock washer. The tiny cotter pin, No. 25 fits into a channel in the stem, and goes around the stem, not through it. This allows the button to spin freely.

Any leak in a gas tank is obviously dangerous, and every tank should seal up 100%. Anything less will lead to stale gas in a hurry, and you will forever be replacing your fuel. With a properly sealed tank, I’ve had fuel regularly last a year, with the addition of fuel stabilizer in pressure tanks.

 

[Rick Hessler]

Thanks for the great info. Tearing into again right now. I’ll update

[Rick Hessler]

Ok.  Pulled apart, 600 grit sanded both metal discs, put on some gasket sealer, works like a champ.  Thanks folks!  Still have to run it in the water but am confident already.

[boscovius]

I’m glad this subject came up as I was unaware of the need for sealant.  I had wondered about using gasket sealant on the main cork gasket but hadn’t seen any mention of it.  I bought a couple of those awesome little brass floats so I’ll be going back into my tanks again anyway to install them.

[reivertom]

Thanks for this thread. It’s been 25 years since I have rebuilt one and I had forgotten this. I have about 4 tanks to get back working.

[boscovius]

Holy Mackerel!  Has anyone bothered to look up what 3M 847 gasket sealant costs these days?  It’s frightening.

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