My mallory 250 fuel pump took a dump the other week. It still works but pressure was very low, i just wondered if i could breathe new life into it. They do a rebuild kit for around 60 dollars, should i tackle it or just buy a new one ?
Mick

that pump has an internal pressure regulator with a dedicated return port. this is a gerotor type pump and imho is one of the better electric pumps on the market. i would disassemble and inspect it, unless there is some unusual damage and/or you've been pumping trash through it it is well worth rebuilding. this is assuming the motor isn't damaged.

there are two different variations of the 250. one with the pressure adjustment screw on the side (older) and one with the adjustment screw on the bottom (newer).

how do you have the system plumbed?

I run a single #12 to a robb mc filter then pump single #10 to the reg with 2 #8 to the carb and a #8 return from the tank.
I will check which pump i have tomorrow.
Mick

so you're using a return style regulator up at the carb as opposed to a dead head style regulator at the carb with the return coming off the pump?

if you are returning from the regulator at the carb i would check to make sure that is functioning properly first before i went after the pump.

i ask about the pressure adjusting screw because the new/old style pumps take different rebuild kits.

this is old style below



this is new style below



if you're using a return style regulator the center port shown with the label above it should be plugged and iirc there may be a steel plug that is installed in the regulator portion of the pump so maximum pressure is pumped to the return style regulator at the carb

I'm using the larger holley reg with no return, just the return from the pump to the tank.
Mick

Does that pump have a screen in the inlet?

Might check that.

it did from the factory. i would rule out the regulator at the carb before tearing into the pump. if the holley regulator is ok then the regulator in the pump may be suspect. the internal pump regulator is set at 15# from the factory which means you should see 15# at the inlet into the holley regulator