Community Forums

4x4van · 06-08-2017, 11:18 AM

I would be worried that an emergency inline pump, when not being used, would create some restriction that could accelerate the demise of the in-tank pump.
"If" you can draw fuel through a failed in-tank pump, then the easiest way would be to install 2 T's in the main line, with a shutoff valve between them on the mainline. Plumb the new pump between the T's in a bypass line. While the in-tank pump is working, the valve is open, allowing fuel to flow to the engine. To use the backup pump, simply close the valve and power up the pump.

If you can't draw fuel through a failed in-tank pump (as your RV repair place claimed), then the generator pickup is all you've got to go with. The pickup tubes on my last RV's in-tank pump were all the same size, not sure if that's the case with yours.

ransil · 06-08-2017, 01:24 PM

If you are worried about it just replace it now otherwise I would not worry about it.

badturks5 · 06-08-2017, 05:01 PM

Quote:

Originally Posted by dix39

We have a '94 454 TBI Flair with a little less that 50k miles on it. The fuel pump is in the tank, not the easiest thing to change along the roadside or even at home. Lately I've been thinking about adding a backup pump located outside the tank and wondered if anyone here had already done this or could offer advice?

Thanks,

Steve

I have done that many times with low psi TBI Chevy systems. Just be sure the pump is set form the right psi otherwise also use an in psi regulator. I put the unit by the inline fuel filter. Make sure you use a key on hot and not only hot during cranking. Also make sure you put an inline fuse where you can reach it. Last have a good clean ground. It will last for years,,,,,, do this only after the main pump fails. If you just put it on for just in case you are asking for trouble. You will end up starving the engine for fuel under heavy load

dix39 · 06-08-2017, 10:30 PM

My first thought was to do as 4X4 van suggests which would not be in in line until needed. If fuel cannot be drawn through the existing in-tank pump I will explore doing the same thing with the gen line if it is large enough.

IMHO, anything mechanical can fail at any time, usually at the worst possible time. I'm trying to avoid that possibility with the fuel delivery system because of the difficulty of changing the in-tank pump, and to avoid being "dead in the water" in the middle of city traffic or out in the middle of nowhere.

I will have to sort out pressures and other issues relating to adding an additional pump. I have factory shop manuals to help me with this. My intent was to add the pump "in case" for the reasons above. It will not be running or in line until needed and therefore I don't think it will interfere with the fuel quantity being delivered by the in-tank pump, but maybe I'm missing something. I haven't done this before.

badturks5, did you pull fuel through the in-tank pump?

Thanks for the help and good advice.

Steve

Demascus49 · 06-23-2017, 02:27 AM

Quote:

Originally Posted by Sbrownstein

I experienced cavitation and pump failure at high temperature with my 1997 Bounder. Never ran with less that 1/2 tank when it was hot and managed to avoid replacing in until I traded it on my new coach in 2015. Some have had success adding an external pump on the fuel rail with a crash switch. I think they use this pump. https://www.napaonline.com/en/p/BK_7356878

It certainly ain't cheap but apparently works. Replacing the pump can be difficult depending on your specific coach. On my Bounder it was between welded jack supports and a real project to fix. Glad I managed to live through it.

I too have a 97 bounder, the levelers stands are a pain in the ass to get off. Especially the first time since 1997. Took us three weeks and two cans of PB Blaster, 1/2" breaker bar and three foot cheater pipe on that. Wish there was an access hole to get to it. Ugh! Oh the real killer is you can't find a new sending unit to go with the new pump. ( Mine was damaged. )