I am restoring a Tokheim 300 and the side apposite from the receiver side has a hole which looks like it is for a reset for the computer but this is done with the receiver handle when the nozzle is lifted out and flipped over. Should there be two ways to reset it or is this hole not used? It did not come with this handle or should it be there? I see some do have this handle. If its not to be used I will weld it shut. Looks like the same handle on my 39 model I restored. Thanks

It looks like a hex bolt head but is actually a breather.

Thanks. Now I know. Think I will weld it up.

That is a vent.

Larry

As Larry said, it is a vapor vent.

Jack Sim

LOL

Thats the air eliminater vent off the tokhiem suction unit. The suction unit had a float in the top that when it started it would let the air out until fluid filled the chamber and the float closed the air vent and let the fluid flow to the meter and out the nozzle. Most all suction pumping units had an air vent.

Gene

Not quite Gene

Yes ...that is the air eliminator vent..but your theory of operation is not correct.

The large float in the air separator part of the pumping unit would let air/fluid in, until the fluid pushed the float up to its closed position. The closed position was actually a mechanical valve ( part of the float assy.) in the bottom part of the float, where it screwed into the pump unit. The float never closed the air vent, it just closed the inlet where the fluid would enter the air separator part of the pump unit. During that operation, air would be released through the air vent.

You could actually run the pump unit with the air separator cover removed, after the float closed the fluid inlet..I;ve done this a few times while rebuilding pumps in the shop, just to see what goes on in there..

Thanks Tom , You are 100% correct.

Gene

IMO I would replace the air vent bolt instead of welding it closed.. The Pump dump website or Tom Buckles here on Oldgas should have that part.