Ford 4500 injector pump fuel line questions

MikeMyhre

Member
I have replaced my injection pump and I am back to trying to bleed the system again (not an easy tractor to bleed). I found one small leak in the fuel line feeding the banjo bold on the side of the pump and I am looking for a replacement. Original would be good, but I could go to a banjo adapter to standard plumbing lines. If anyone has any ideas of where to get a replacement, that would be good.

I am also trying to understand the fuel flow. I have a single line coming from the tank to the fuel filter. The filter shows two outlets that go to the side mount banjo bolt (by the bleed screw) and the other one to what I would have thought would be a pump output, not inlet. Is one of these a 'clean' fuel return line even though the filter arrow shows 'out'?

As for bleeding, since the 4500 is a gravity feed system, I think it would be a good idea to put an optional electric fuel pump on the tank side of the filter. When I put an air compressor in the fuel tank to give extra pressure, it often adds bubbles (unknown vent?). I am thinking a 'T' inserted in the tank to filter line that has a check valve on the extra leg of the T where a fuel pump could be added when bleeding. Right now as I open the injector pump bleed screw, and crank the engine, I just get dribbles timed with the engine crank. I have seen this before on the old pump before I got it started. Many told me I still had a bubble in the pump and I think they were right. The question is what is the easiest way to get rid of this bubble?
Thanks,
Mike
 
The banjo fitting is return to filter. The supply is on rear of pump.The supply pump has plenty of flow to supply pump, fuel cools and lubs pump. When running there is pretty siginfant fuel flow back to tank
 
I have a 4600, and my son has a 4000, pretty much
the same as your 4500, except ag versions. No need
for an electric fuel pump. My 4600 has gone more
than 10,000 hours without one.
Are you bleeding the fuel filter first, and then the
pump?
 
(quoted from post at 12:05:19 10/05/18) The banjo fitting is return to filter. The supply is on rear of pump.The supply pump has plenty of flow to supply pump, fuel cools and lubs pump. When running there is pretty siginfant fuel flow back to tank
Thanks for clearing that up!!
Does that mean I should bleed fuel out the banjo before using the tiny bleed screw? I have the feeling there is a big bubble in there somewhere with no way out.
 
(reply to post at 12:07:38 10/05/18)
bleeding...
Yes. I bleed the filter first, then crack both nuts loose on the injection pump to allow the lines to drain air. Then open all injectors and bleed screw. Then crank the engine, dribble, dribble, dribble, in time with the engine cylinders from the small bleed screw. When bled right, the small screw will shoot 5 or 6 feet when cranking. Now nothing. Until that has more pressure, I won't get any fuel to injectors.
 
What is the filter brand? If NAPA/WIX did you make the common mistake of placing an extra O ring in the filter top outer groove? That's the fuel inlet, and must be open. Many service calls made to correct that problem.
a281747.jpg
 
(quoted from post at 13:24:43 10/05/18) What is the filter brand? If NAPA/WIX did you make the common mistake of placing an extra O ring in the filter top outer groove? That's the fuel inlet, and must be open. Many service calls made to correct that problem.
a281747.jpg
I think I have made that mistake before. This time I started it and warmed it up. Then swapped the injection pump. Never touched the filter. Should have only needed to bleed the system (assuming the new injection pump is good).
 
What is the filter brand? If NAPA/WIX did you make the common mistake of placing an extra O ring in the filter top outer groove? That's the fuel inlet, and must be open. Many service calls made to correct that problem.
a281747.jpg
 
I have the feeling there is a big bubble in there somewhere with no way out.
I got the new filter assembly and installed it. I also bought a small electric fuel pump and put it on one of the extra ports of the filter assembly (inlet). I turned off the tank valve (gravity feed) and turned on the fuel pump to force fuel into the injection pump in an attempt to force fuel in and air out. With the small bleed screw removed on the injection pump and the fuel pump on, I got fuel to shoot out the bleed screw port about 5 feet. Turned the fuel pump off and opened the tank valve. Started cranking and it was still just a dribble out the bleed screw port. This is when my starter died and I had to wait a few days for a new one. Installed the new starter. Same deal, still no significant flow through the injection pump. I decided to try fuel pump on, tank valve off, while cranking, but that didn't help either.

Any ideas on how I can better bleed the injection pump? It was running fine before I swapped it out. Since I have had problems bleeding the old pump in the past, I don't suspect the new pump is damaged or defective, just needs to be bled.
 
Mystery solved and backhoe running again!!
So the injector pump I got on Ebay (claiming to be new) had a siezed low pressure pump.
This morning I took both my original pump and the 'new' replacement injector pump to a Injector repair shop. He took it apart and found the shear shaft had broken and the rear end seized. He then took my original pump and did a quick inspection/filter/gasket replacement.
I installed it in the backhoe this morning and bled instantly at the pump and within 15 seconds at the injectors. Cranked it over and it started within 5 or 10 seconds!
I can't believe I wasted a week on the bad pump. It was shinney on the outside, how could it be bad... ;-)
Thanks for the replies.
 
(quoted from post at 06:05:48 10/20/18) Glad to hear you got it working.
Thanks Sean,
Your post helped me understand the fuel flow which saved me a lot of time. Thanks!
I also got a good education at the Injector Pump service shop.
Understanding how it is supposed to work is a HUGE help.

Mike
 

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