Fuel system priming

[Paddy]

Hello all,

It's been a while since I've had to prime my KAMA 454 fuel system. Attached is a photo of the injector pump. Just to the right of the pump is a banjo fitting with a bleeder valve. I pump with the bleeder valve open until clear fuel comes out? I wasn't getting much after 20 pumps. Or is it that small hex bolt with slot screw just the right of the 3 out put lines? I understand once I see fuel without bubbles, I'll need to bleed at the injectors while cranking.

As a side note, I'm thinking of changing the paper cartridge fuel filter to a spin on type. Wix 24770 looks like a good fit. Has anyone done this and id so, how to you bleed the fuel filter? The old one on the tractor has a bleeder on top.

Paddy

 

[Bob Rooks]

The banjo bolt with the plain hex head bolt (on right) is actually a spring loaded ball-check valve built into the banjo bolt. This also serves as a pressure regulating valve for the fuel cavity in the injection pump. Where is the return fuel line that comes off that banjo bolt? If you want to bleed air from the fuel cavity use the slotted hex head screw to the left of the barrel and plunger assemblies.

Curious why you want to change fuel filters. They are both paper elements. Did you compare micron ratings?

 

[Paddy]

Bob,

Thanks for the heads up where to bleed. I did back off the small bolt on the right banjo fitting and found the spring and ball inside. So assume I loosen the hex/slotted screw while pumping?

When I pulled the fuel filter down to replace, I noticed a bunch of rust partials on the clean side of the filter. It must not be sealing well. The spin on type will have a fresh gasket each time. Spin on Filters can be bought with differing micron levels. What level do you recommend?

I saw where someone installed one of these WIX filter bases with a brass shutoff with a bleeder. So I should be able to shut of the fuel after the filter, change the filter. Then turn the fuel back on and bleed it right to the ball valve.

 

[Bob Rooks]

You can install stop valves on each side of the filter head, and fill the new filter with clean fuel before you install it. No bleeding necessary unless you want to.
I have a 2 micron Racor filter/separator on mine. Most spin-on filters are 10-25 micron.
"So assume I loosen the hex/slotted screw while pumping?" Correct. Actually you don't even have to do that. Just pump until the plunger gives resistance and you should be good to go - provided you filled the new filter with fuel.

 

[Bob Rooks]

So where is the fuel line that attaches to the banjo fitting with the ball-check?

 

[Paddy]

Bob,

The fuel line from the filter goes to the bottom of the primer pump at a banjo fitting. Then goes to the banjo fitting with the spring ball valve. On the other side of the injector pump, it loops down on the left side back the primer. I assume just a loop.

 

[Paddy]

Bob,

The fuel line from the filter goes to the bottom of the primer pump at a banjo fitting, two barb banjo fitting. Then goes to the banjo fitting with the spring ball valve. On the other side of the injector pump, it loops down on the left side back the primer. I assume just a loop.

 

[Paddy]

Bob,

The NAPA 3528 is also 2 micron. So should be good to go.

 

[Bob Rooks]

Bob,

The fuel line from the filter goes to the bottom of the primer pump at a banjo fitting, two barb banjo fitting. Then goes to the banjo fitting with the spring ball valve. On the other side of the injector pump, it loops down on the left side back the primer. I assume just a loop.

Ok, I just didn't see a hose on it. This is a trick that only the Chinese seem to do - run the fuel return line back into the lift pump suction. I caught that on mine and corrected it with bypass valve return to the tank. Not absolutely necessary, but it allows fuel contaminants to settle out in the tank and be filtered again, and to cool the fuel.