[rodneyU900]

All,

I’ve a new to me Case 406. When I got it, the engine ran great if it was under no load. No problems revving to any RPM. However, driving up any incline, the machine would lose power dramatically and RPM’s would drop quickly. Second gear would be required to climb any hill (in high range).

the fuel filters were like new, but I replaced them anyway. The small sediment bowl off the tank had just a bit of crud, not nearly enough to restrict flow. I removed the tank and cleaned, but it was in good order. There is no obstruction in the air intake. The pick-up tube is clear (though there is no screen or anything).

I’d been running fuel cleaner while the truck idled for long periods. It ran out of fuel. I topped up and primed with the manual pump and it started and idled just as before.

Today the truck started and died. Will not start. Have any ideas? Is it possible the lift pump is hosed? Seems to be no air in the lines. I thought the lift pump is mechanical and not sure how/why it would fail?

thanks

 

[Mog70]

Similar symptoms have been experienced with the priming lift pump loosing it's seal see thread below for pictures of the pumps there is also some good diagnostic information in this thread.
419 keeps running out of fuel
I have replaced mine with the newer spring return pump and completely solved all my fueling issues (for 7 years now), but you could also have issues with the suction tube developing pin hole leaks near the top or a fuel line between the pump and the tank leaking. The area between the lift pump and the tank is the suction side so any leak would not manifest as a fuel leak since this hose is under vacuum.
Personally the new manual priming pumps are so much easier to use they should be upgraded as a matter of course on any new to you old mog.

If you suspect the lift pump (or area before the high pressure injection pump), a gauge could be installed on the fuel filters or inlet to the high pressure injection pump to monitor lift pump pressure if pressure drops with power you got a problem before the injection pump, if pressures don't drop look towards the injection pump or somewhere else.