Vaccuum at fuel filter water drain- prove anything?

[ericp351]

Hi all, hope basic question- my A2 needed lots of cranking for a cold start yesterday. 1/2 way thru- engine off-I cracked the (military/big) fuel filter water drain. Was sucking air in. Does that prove any trouble? Thought that that might prove suction lines OK. Note that that filter was new 100 miles ago + reassembled carefully. Thanks.

 

[Jbulach]

If it’s the big filter mounted on the fender behind the tire, and before the lift pump, and your fuel tank is lower on fuel, probably not. Likely just the fuel draining back the line and down the pickup tube. However, my last battle of the war on fuel flow and pressure problems, was smallish chunks of the old rubber fuel return dip tube, partially plugging my pickup tube while going down the road, and loosing power or dying. So, I wouldn’t be afraid to pull the tank and hot pressure washing every last little speck out of it. Also if you have a rubber dip tube replace it and the pickup with stainless while you’re in there.

 

[ericp351]

If it’s the big filter mounted on the fender behind the tire, and before the lift pump, and your fuel tank is lower on fuel, probably not. Likely just the fuel draining back the line and down the pickup tube. However, my last battle of the war on fuel flow and pressure problems, was smallish chunks of the old rubber fuel return dip tube, partially plugging my pickup tube while going down the road, and loosing power or dying. So, I wouldn’t be afraid to pull the tank and hot pressure washing every last little speck out of it. Also if you have a rubber dip tube replace it and the pickup with stainless while you’re in there.

Thanks for fast reply. Tank is full, truck slightly parked nose high. Runs OK post start. Wondered what "Normal" should be at that drain-yes, the big filter, aft of fr tire, should be at "engine off, cranked a bit". Thinking holding vac and no water, no fuel OK, but wanted to ask 'old-timers'.