In line aux tank fuel pump

[burlman]

I recently bought and installed a 60 gal, gravity feed, RDS aux tank for my F350. It works great, with one problem. Having a "continuously" full fuel tank tricks the truck's on board computer into thinking I have a problem, and the check engine warning light comes on. I'm thinking of installing an in line pump that I can control from the cab to fix this. Let the OEM tank empty naturally then turn on the fuel pump to refill as necessary. I've heard good things about Holley pumps, and nothing but bad things about Mr. Gasket. Does anyone have any suggestions or other solutions? Thanks.

John

[dcg9381]

John I've used holley pumps with success on TBI applications (pressure between a carb and EFI). For a fuel transfer situation, I think these are overkill and I'd likely use a simple Airtex type pump. I think AirTex builds the pumps that are used on Onans. Low pressure, not huge volume. Cheap, easy to install. Amazon has the Airtex E11015 for about $30.

I've read about people having Ram's reprogrammed to account for the larger tank size. I don't know about the Chevy (or associated costs) - but that might be an option too if the gravity feed is working just fine and you'd like to get your miles-to-empty to display correctly...

[bsmith0404]

Check with ATTA, if I remember correctly they have a solution to the Ford check engine light issue with aux tanks.

As for the two pumps, I'm assuming you're talking about the small green Mr. Gasket fuel pump part #12D, I went through 2 of them. The first one lasted about 15k miles and only failed because I forgot to turn it off and the tank had run dry so I burned the pump up. The second one lasted about 3k miles.

I now have the Holley version that looks like the same pump, but black housing. It looks like it's the same, but actually operates differently. That one has been running now for about 50k miles without a problem.

To be honest, the pumps don't really run much. If you have them installed correctly, all you need to do is turn the pump on for a few seconds to establish a syphon and it'll just about drain the entire tank into the main tank while you drive. Every now and then it'll break syphon and you just have to turn the pump back on for a few seconds to get it going again. I reset my gallons used setting on the truck when I refill the tanks so I know how much fuel is in the aux tank since I never added a gauge to it. When I've used 65 gallons and the main tank is full, I know I've drained the aux tank.

[burlman]

Thanks for the inputs, guys. I went ahead and bought a Holley and will connect it to one of my Upfitter switches in the cab. I'll let you know how it works out.

[bsmith0404]

Does your tank feed into the filler hose or the overflow hose on your main tank? The best way is to feed into the overflow. ATTA makes an adapter with 2 nipples, the downstream one for the fill coming off of the pump and the upstream to for an overflow to return back to the aux tank. That method will help maintain the syphon better. On the most recent trip, I drained the aux tank three times (3400 miles) and probably only used the pump for a total of 10 minutes.