Simms-Minimec injection pump

[jhwis]

Changed the oil in the injection pump on a 7700. It was mostly diesel than came out. Tractor runs great. Don't know last time it was changed. What causes this and just keep changing it at regular intervals? Where does the oil go or does it just get diluted? Just curious.

 

[showcrop]

I used to change the pump oil in my 9000 after every other pulling competition. The fuel pushes past the plungers. My pressure was set to the max, yours should be much less. Is the thin wire seal still on the pressure adjusting screw? If not your pressure is most likely higher than when built. High pressure really doesn't hurt. It just makes smoke along with more power.

 

[Keith Williams]

On my 7000, I changed the oil at every oil change. I changed oil at 50 to 75 hours (yearly).
The pump housing is aluminum, so be careful how tight you snug the bolts!
It gets diluted by fuel leaking from the pump internally, so that will get worse over time.
It would be easy to miss, so who knows how long it has been since changed. It's good you found it!

YMMV

 

[shaun wallace]

It seeps around plungers when running. When gets to full it drips out the tube on rear of pump.

 

[Bern]

I used to change the pump oil in my 9000 after every other pulling competition. The fuel pushes past the plungers. My pressure was set to the max, yours should be much less. Is the thin wire seal still on the pressure adjusting screw? If not your pressure is most likely higher than when built. High pressure really doesn't hurt. It just makes smoke along with more power.

It's not a pressure screw, it's a volume screw. Turning this screw does not increase the pressure, it increases the duration of the injection event, which equals more fuel in the cylinder and therefor more power.