Those of you running a Fuel Sump

For those of you that are running a Fuel Sump:

Are any of you having a priming issue with frame mounted lift pumps?

Problem:

Truck has 1/2 a tank of fuel

Have an AD II 165. Truck started giving issues of low fuel supply. Limped to work and replaced filters as it had been a while. Filled both filters and let system run, started truck. Runs good. Let it idle for a bit, and truck dies. Filters are empty. Check supply line to pump, I have fuel. Fill filters again, but won't push fuel to injection pump.

I have a spare Raptor 150 that has been my back up, and throw it on with a stock filter housing. Pump primes, and truck starts perfect. Let it run. No issues. Figure I'm done. Shut truck off, clean up. Go to double check and pump has already lost prime, and will not pick fuel up.

I remove fuel line from the sump, and I have fuel there. I pull line from lift pump, and nothing. Let it hang low, and I have fuel.

That whole gravity bleed, liquid won't run out if nozzle is higher than level of liquid is giving me an issue.

Ideas?

Thanks,

Ray

I haven't had any problems with my sump, and frame mounted Fass, even at less than 1/4 tank. Sometimes it takes a second or two of the pump running to build pressure before I start the truck, but never had an issue with it not bleeding at all. Maybe installing some sort of check valve would help?

Before I put an actual pressure regulator after my ppump and removed the overflow valve I would have a problem loosing prime if I had less than a 1/4 tank and parked somewhat slanted. It would pick fuel up right away and re prime but it would push some air through the lines and hard start.

That being said I never had a problem with more than a 1/4 tank, and zero issues at any fuel level once I put the regulator on.

Also this is not an Airdog setup

Did you clean the tank before installing the Sump? I'd drain the tank for a bit to see what all comes out into a clean bucket. I know the AD150s have a viton ball that is supposed to hold prime. I imagine the ADII and raptor are the same way.

cumminsman315 said:

Before I put an actual pressure regulator after my ppump and removed the overflow valve I would have a problem loosing prime if I had less than a 1/4 tank and parked somewhat slanted. It would pick fuel up right away and re prime but it would push some air through the lines and hard start.

That being said I never had a problem with more than a 1/4 tank, and zero issues at any fuel level once I put the regulator on.

Also this is not an Airdog setup

Click to expand...

I have that same issue. I'll try the regulator install to see if that fixes the issue.

Thanks!

hydroshok said:

Did you clean the tank before installing the Sump? I'd drain the tank for a bit to see what all comes out into a clean bucket. I know the AD150s have a viton ball that is supposed to hold prime. I imagine the ADII and raptor are the same way.

Click to expand...

Sump has been on for nearly two years now. With the Raptor pump, I use a factory 12v filter housing, and see some sediment in the bottom from time to time during a filter change. No large particles stuck in the rotors on the Raptor though.

I removed all of the straps that keep the line from the sump to the Raptor safe and tight, and then let the line hang, but still connected. I went back to the truck about 3 hours later, pulled the line loose from the lift pump and fuel began rushing out. Connected and all is well.


Thinking age of hose may have allowed a collapse issue? I can't officially say. I hate when issues work themselves out without a known fix.

My OFV went on my P-Pump last night. Here is a simple test to see if it is your return line or an issue with the viton ball/spring in there. I kinda felt like Macgyver when I rigged this up. Just remember to take the blade out first...