This add on --not factory--lift pump pumps 1 gallon in 3 minutes... QUESTION If I am just running the electric lift pump with key on tractor not running----Should I see the diesel fuel recirculating up thru the filters thru pump etc. and back into the tank???? I am NOT SEEING the fuel going back into the tank in a NONRUNNING situation. Thanks for the previous help--much appreciated......... len in michigan
Actually I don't think so. With the mechanical lift pumps when you prime them they come up to pressure and just hold there.
Lan is correct.. the injection pump only returns what the pump doesn't want/ need.. IN a "non-running" situation.. why would it?
ON THIS JD 644 A--Where would I install a check valve if I think the fuel is returning to the tank and draining the system..........??
In the non-running situation--I have the key on and the electric fuel pump is pumping fuel out of the below fuel tank------where is that fuel going????
The fitting on top of the injection pump where the return line hooks up IS a check valve, assuming the glass ball and spring are still there and in working order. The pump may be pulsing but it's probably not actually pumping any fuel anywhere, just holding pressure. Unless the original mechanical pump is still in line then it could be filling the oil pan with diesel if the diaphragm is rotten.
I KINDA THOUGHT it was just holding pressure--Thank you for that information. The mechanical pump has been removed.. I am thinking the check valve is not working properly as the system rather quickly drains itself. Could I just install a check valve or a ball shut off valve just above the injection pump----is that where it should be located????
Ball valve would work until you forget to open it. Adding a check valve would add back pressure and may cause the injection pump to malfunction. Only takes a minute to remove that return fitting and check it over, a few bucks for a new one. Really though I kinda doubt that the system would siphon fuel out of the pump, it would have to suck air someplace to allow the fuel to drain back to tank. Are you having to bleed it to get it to start or?
Do not have to bleed the system.--Maybe low compression. It takes just a wiff of ether thru the factory installed system in the cab. Then shut it down and it will restart. Let it sit for an hour and it will not start again.