Simple oil pump not so simple

[hvac/airplanes]

I replaced a seized oil pump today on an older oil furnace with same rpm, rotation, and gpm. Simple right? I called for heat and started the bleed and as I got a solid fuel column, system cut out on safety. Hit the reset button to finish the bleed and now it won't bleed, nothing comes out of my bleed port. When I installed the new pump, I replaced the coupling and verified the motor was turning the pump, it was. This pump is a single stage 2 pipe system (supply/return). This suntec pump requires a small plug (5/32) be installed in the return port before hooking up the return line, which I did. I also verified no obstruction from tank to filter by syphoning, yummy. The filter is also brand new and the cartridge clean. I tried several times to bleed with no sucess. Pump press. was zero with no fuel of course. What gives?

[dandyme]

hook a vacuum gauge on the inlet, see what's going on there.

we are not there, when you hit "the reset button" did the burner motor come on?

[beenthere]

Moved to Tech to Tech forum.

[hvac/airplanes]

yes, the burner motor comes on each time.

[snupytcb]

did you try supplying oil from a differant source? process of elimination.

[Joehvac25]

One I had one where the pump coupling stripped but only would disengage at a certain point, I kept manually spinning the blower wheel and finally I noticed the dead spot, I know you replace it but maybe have another look.

[Tecman1]

Sometimes it takes a few starts to draw a vaccume and start the flow from the bleed port. You can jump out the eye and let it run with the bleed port open without it going out on saftey. If still no luck verify gravity flow from the tank. There is the possibility of a bad pump out of the box or some problem with the coupling.

[beenthere]

WAG. The Op didn't close the bleeder as soon as the burner shut off and the oil dropped back into the tank. Now the pump gears are dry, and it isn't able to pull as high of vacuum to get its prime back up. Worse yet, probably didn't need to bleed it in the first place.

[MicahWes]

I agree with been there. It probably needs to be primed once or twice by pouring oil in the pump housing. If it is two-pipe, and the tank isn't terribly high or low in comparison to the pump, it shouldn't need to be bled after this.