5 ton fuel tank selector valve cleaning/rebuild

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Finally finding time to tinker with the XM818.

With new batteries in her all the electrical seems A-OK. Even confirmed she has power to the Fuel Solenoid. So now chasing the fuel system.

The EMERGENCY Fuel Cut-Off Cable and Valve are both functioning properly and I've confirmed the Fuel Cut-Off Valve is in the "Run" position.

Primer Pump would hardly budge the Fuel Pressure Gauge's Needle, so I replace the Primer Pump's O-Rings. Now the Primer Pump will make, BUT NOT HOLD 30 P.S.I. with vigorous pumping..... even without cranking the engine AND without the glow plug energized.
Looks like it's on to the Selector Valve and Rubber Hose inspection/replacement as my next indicated step(s).

THANK YOU for the wealth of information archived in this thread. More on this as we progress towards "The Shepherd's" RESURRECTION !!!
Dash primer will not hold pressure since it will bleed off for starting while glow plug is energized.
Thanks for that input, tractors0130.

I added the BOLD and UNDERLINED condition into the quote above. I should have included that detail originally. The fuel lines simply do not hold pressure, seemingly indicating leakage somewhere else.
 

Rogarner

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I'm working on my M817 with dual tanks and selector valve, My question is about the return fuel line coming from the engine, dose it swap from tank to tank as you draw from the left or right tank? Common sense would lead me to believe it's got to work that way. If not the return line would over fill one tank or the other. I've done a good bit off digging and couldn't find anything about the return lines on a dual tank setup. So I was thinking maybe some of you guy that have rebuilt the selector valve may know the answer to my question. Thanks
 

86m1028

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Wanted to say thanks to this post.
Just picked up hose & o-rings.
Spent just under $30 for enough hose to replace all 8 hoses & they threw in the o-rings for free.
Now to go install it.
 
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gstirling

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Joesco - I just replaced my fuel filter (m936a1) and had a hard time getting fuel back to the engine. first air leak was at the bolt on the top of the filter - found this as it leaked fuel at first. then my priming pump quit working - and it was the second air leak source (I think). once I replaced the two O-rings in the manual prime pump, and refilled the fuel line - it fired right off, if it fires off tomorrow (i.e. fuel line does not drain down over night), then I will be certain I have found all the air leaks. good luck.
 

msgjd

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Haven't seen any mentions in this or other threads about the Anderson Brass Co. They made valves for the M809-series. They do sell the complete valves, and many of other designs. They also can provide you with the small internal parts. A couple years ago I needed a couple new stop-washers, the ones you see under the handle that limit handle travel. They sent them pronto, never bothered to invoice me nor ask for postage. I have also purchased different valves from them for use on custom projects. And as far as M809-series fuel hoses to/from the selector valves and the hose from the filter to the PT (injection) pump, I stopped buying NOS hoses due to their age. Most auto supplies or truck shops have Gates or equivalent diesel or biofuel-rated hose by the foot. The brass fittings on the M809-series are barbed and are re-usable. The originals might look crimped or special, but they are not. Just cut the old rubber hose off the fittings, and slide the new hose in place and you're good to go. Just make sure the hose bore has been flushed clean after assembly ;-)
 
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