The Stovebolt Site Forums The Shop Area General Truck Talk fuel delivery problem last night

I drove the truck (51 3100) to the store last night, and on the way home, I ran out of gas After 30 years without a stovebolt, you would think that I would remember that those two marks on the gauge aren't for 1/4 tank and 3/4 tank, but since it goes all the way up to F when it's full, that's what I thought. Anyway, after calling a friend to bring me some gas, it wouldn't start unless I poured it down the carb, and then only ran till that was gone. The fuel pump is fairly new, and the PO told me he had this problem. So, my question is, since the tank feeds out of the bottom, I'd like to remedy that, and I'm wondering if the '54 sending units will fit (and work) in place of the bottom feed '51's. The tank is "new", as are the hoses, etc. I don't plan on running out of gas, and wouldn't have if I'd known exactly where empty is on the gauge (I know now!), but it would be nice to think that if I ever do, I won't have to worry about any crud in the bottom of the tank causing me to clean out my system, and call AAA to bring the truck home, like I did last night. A 2 mile trip. SO, will has anyone else had that problem? And does the '54 sending unit, which sends the gas out of the top and has a screen on the unit, work with the behind the seat '51 tanks? Thanks for any help on this, folks! Lee (note: I'll be outside under the truck for a while, so I'll get back in here after while)

The fuel pump shouldn't have any problem with sucking out the fuel out of the tank from the top.

But I don't know if the resistance on a '54 sending unit is the same as on a '51.

Yes, the '54 unit will work and the resistance is the same. (30 ohm)

Same electrical resistance, 0-30 ohms (GM up through 1964, supposedly).

Wow, sorry to hear that you ran out of gas. My 52 1/2 ton o fun is only driven locally and anytime I can find the time weather permitting. I top off my tank when it reaches half, this has worked well for me.

Now we're talking about the fuel system, just wondering how many gallons the tank size is on my '51 1/2 ton? Registration papers says 45 liters, which is 11 Gallon if i calculated it right. Is that right?

Standard 1951 cab: 17.5 gallons - 66 liters

Thanks TC!

Forgot to mark this, so here's the deal. Got up the next day ready to take the fuel line apart to "jiggle it a little" like the PO told me he and the PPO would do, which would make it get fuel again. I got in and tried once just for the heck of it and it fired right up. Go figure. Either the ride on the flatbed jostled it loose, or it sucked water off the bottom of the tank, or maybe I flooded it, I don't know. Anyway, it started right up with 2 gallons of gas in it, and a ride on the big red truck. But when under the truck yesterday, I looked up and didn't see a rubber grommet where the fuel line comes through the cab floor, and I also saw a radiator type hose clamp instead of a fitting. The hose seemed to be pressed hard against the hole perimeter, and I don't like that at all, but just the idea that it's put together with the wrong kind of fitting, off center, at such a critical place kind of gives me the creeps. Visions of flaming gasoline leaks under my butt fill my head. So, I'm now going to put all missing 'real' parts on where they aren't. Funny thing about all this is, it's the second time I've had AAA carry it home for me since December, and it stopped about 100 yards shy of where they picked it up before. (Died and wouldn't start while driving down the on-ramp to the highway. Turned out to be a bad wire from the ignition switch to the ballast resistor). Anyway, thanks for the info on the sending unit. The gas tank is new, the hoses are new, and I'll bet the same goes for the sending unit, but no screen over that feeder hole in the bottom of the tank seems like a bad design. I'm wondering if a tank screen like the one in my old diesel Mercedes 300D would work in these tanks? All I know is, it runs, and it keeps me busy!

A filter at the bottom can easily be added

..pic..

You can choose to use a clear filter if you suspect crud.

Dads50- Nice!

I thought I'd go ahead and put this on here. I took a picture with my phone while I was under the truck, and this is what I've got at the exit hole of the gas tank.

picture

If...and I say If....you set it up the way the truck came from
the factory, then it will perform the way it did when it was
new. Pipe nipple out of the bottom of the tank, fuel shut-off
for servicing, one addition I'm all for is, as Gus points out,
an inline filter after the shut-off, then run to the pump,
then run to the carb. The GM AC accessory glass sediment bowl
was installed on many with out an inline filter before the
pump but that can cause problems if crud gets into the fuel
pump and screws up the valves. I ran my 50, 216 as it would
have been setup from the dealer with the AC sediment bowl for
a couple of years and had to clean the screen in the fuel pump
a couple of times a year, then decided to add the inline
filter. I like a clear ones so I can see when it needs changing.
http://www.pbase.com/dennygraham/image/155908075

If you have a new tank there shouldn't be any crud getting in
the system all the way to the carb unless you are picking it
up at the gas station. If the tank is full and you're on
level ground, gravity is pushing the fuel, nearly up to
the top of the block. A good fuel pump should have absolutely
no problem getting fuel up to the carb in about 10 seconds
even if the truck has been sitting over the winter.

I installed a new dual action fuel pump for a friend a few
years back. The truck only ran a few miles and then it sat in the
garage the rest of the time. We went to start it recently and the fuel
pump was not pumping. I have a feeling that from sitting with
E10 in the pump that the diaphragm or valves may have swollen
or gummed up the works. I have the same fuel pump, put on at
the same time, on my '50, 216 and haven't had a bit of problem
with it, but I drive mine all the time.

dg

valve is now reproduced

...click...

That's good to know Gus, I've rebuilt mine a couple of times
using graphite valve packing twine. Just did it back before
Christmas this time. Might pick up a couple to keep on hand.
tks
DG