The Stovebolt Site Forums The Shop Area The Electrical Bay Fuel Sender hitting tank?

Gents,

I finally have everything working correctly, now that I have time due to retirement and when I filled up, my tank goes to 1/2 full. When I pull the sender out of the tank, the needle moves all the way to full. I’m curious if I have the sender float pointing the wrong direction. I assume it’s hitting the tank. Once the tank gets to below half full, the needle is correct.

Thoughts?

Chris

PS: all stock (12v) gauges/wiring/sender. Works perfectly outside the tank (with truck wiring) and below 1/2 tank.

1951 3100

Re-clock it and see what happens.

Did you orient the new unit in the same direction as the one you removed? It should be oriented side to side, not front to back.

Been there.

The hole pattern doesn’t line up at all positions. Gives very limited clocking options.

After consulting some folks here, I gently bent mine with a couple crescent wrenches so that it lined up nice and parallel.

Otto,

I’m not sure if it’s the same as I put a new tank in years ago and I’ve been fighting it ever since. I finally had time to address it.

JW51,

I’ll try another position and if needed, I might attempt the slight bend.

Thanks,

Chris

My ‘56 was the opposite… it was good from 1/2 to full, but would only drop to 1/2 tank. Removed the unit, bent it a little, and then it was like yours! …good only from 1/2 to empty. Removed it again and bent it slightly back to find that sweet spot. Reinstalled and works perfectly, now.
Greg

Yeah, the float is probably hitting a baffle inside.
Reclocking it,the holes don't quite line up.
On my panel I was able to widen one hole on top
of the sending unit and able to tighten it down.
There is of course a gasket and the head of the bolt still covered the hole.

Every sender I've played with in the last bunch of years, can be clocked on the itself.

I don't know about AD but TF sender 5 hole pattern is keyed. Only goes in one way. I'm noting you say stock tank, stock sender and stock gauge. Ay any rate with a long skinny tank there are only two ways to try. A piece of wire or a flashlight should identify baffles.

"Works perfectly outside the tank (with truck wiring) and below 1/2 tank."

I don't understand that statement? Works perfectly outside the tank, still wired to gauge and still grounded to truck chassis, but only below 1/2 tank? What does that last part mean? Did you move float from stop to stop and observe needle? needle goes from empty to full as you move float?

As I recall, the screw pattern allowed for installation in two positions. I installed my new tank and sender in 2021 so I can't remember exactly. It seems like I stuck it in two different ways and chose the best one.

I could be misremembering completely, though.

Here's the original tank. It has a keyway.

Bartamos,

I bench tested it, then hooked it up to the truck wiring, without the sender in the tank and retested it. The needle moves all the way from empty to full. I was trying to tell everyone that everything works, until the sender is in the tank. In my opinion, everything (wiring and all parts work) else has been ruled out.

When the sender is in the tank, I can fill the tank all the way up and the gauge reads 1/2 tank and does not move. Once I get just below half tank of fuel, the needle starts to bounce (float is moving again).

So, the only logical reason, in my mind is that the float is hitting something and the sender range of motion has been restricted (ie side of tank or a baffle).

Chris

Is the tank behind the seat?

Otto’s post aligns with my recollection from last fall. I believe the sender will line up at two positions. In my case, one was totally lousy and the other was slightly less lousy.

NDKid’s diagnosis and logic makes sense to me. One other thing to check if you haven’t already: Make sure the float isn’t leaking.

Bouymaker,

That unit is completely different from the earlier trucks. The '51 doesn't have a pick up tube like yours. The fuel line is fed by gravity from a hole in the bottom of the tank. The sending unit only has a float arm attached to it, no fuel supply mechanism at all.

I agree it seems like it's hanging up. The only other thing that could be diferent after install is the ground. But I think I read that you have a ground wire from one of the flange screws. Just keep in mind the flange is isolated by it's gasket and the tank is isolated by pads and so on. Your test may have bypassed those grounding difficulties and therefore would not catch it. Don't know how you did the installed ground vs tests. Did this exact setup ever work installed?

As mentioned, check the float for a leak. The floats they put on the new senders have had an issue with the "solder". I don't believe that it is solder at all. I have had three of them leak right out of the box. I now use a phenolic plastic float used on Jeeps. It has the same diameter as the brass float and clips right into place and they work. All three of my ADs have them now.

My old and new floats can be removed and rotated 180 degrees.

The tank is behind the seat. The float is good and the grounds are good. I’ve tested them to ensure that I have overkill with the ground and it runs to the negative battery post.

I’m going to work on spinning the sender 180. If that doesn’t work, I’ll bend slightly and report back.

Thanks for confirming that I’m not crazy!

Chris

Update: I attempted to turn the sender 180 degrees in the tank and the I was unable to get the screw holes to line up due to the float hitting the side of the tank. I placed the float back to the opposite side of the filler neck. I then bent the float rode (after hinge) slightly away from the tank side. I now have full movement of gauge and sender.

Everything works perfectly!

Thanks for all the help!

Chris

Good deal.

Which direction is the float lever pointing, driver side or pass side? Which direction did you have to bend the arm? Toward the rear of truck?

The float is on the drivers side (away from fill neck). I had to bend it towards the rear of the truck very slightly. Maybe 2-3 degrees.

Chris