fuel gauge not working properly

1959 - 1978, M151, M151A1, M151A2, Technical questions and discussions, regarding anything related to the M151.
Tech3140
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Re: fuel gauge not working properly

Post by Tech3140 » Sun Mar 27, 2022 4:30 pm

Yes, rule of thumb: always Carry a fuel stick.

Yea, the float is out of Adjustment. For me, I’m weird this way, at the fuel level, my gauge needs to say full. At 2.5 gal, my gauge needs to say Empty.

Yep, sender unit needs to really be adjusted. Working on that tonite. After a few Gin and Tonic drinks (Hic...).


Rickf
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Re: fuel gauge not working properly

Post by Rickf » Sun Mar 27, 2022 4:49 pm

Yea, THAT"S a good time to be bending things carefully. :roll: :lol: By the way, make sure that when you are testing the sending unit out of the tank you do not touch the wrong wire to the wrong thing since you will have a huge open hole in the top of the tank. Probably be a good idea to put a piece of wood over it.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Hanselandgretel
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Re: fuel gauge not working properly

Post by Hanselandgretel » Sun Mar 27, 2022 5:30 pm

Good airplane driver trick, don't trust the gauge!

Tech3140
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Re: fuel gauge not working properly

Post by Tech3140 » Sun Mar 27, 2022 6:59 pm

Point taken. Yes, any spark with an open fuel tank would really ruined my day. Like stepping on Dog Doo Doo or a land mine. The end results would not be pretty.

Tech3140
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Re: fuel gauge not working properly

Post by Tech3140 » Sun Mar 27, 2022 8:13 pm

Now this sucks.
The NEW fuel sender is eather bad or it’s not for the 151s.
When the float is all the way down (Empty), it works just fine. But at the top (Full), it shows 3/4.
Checked wires? Yep. Check grounds? Yep, did that too.
Cover the hole with a Board, like was suggested? Yep, did that too.
No go. Gauge still says 3/4. Ok, look for the old fuel sender. Think I could find it ??? Nope, it’s gone AWOL.

Crap

Fil Bonica
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Re: fuel gauge not working properly

Post by Fil Bonica » Mon Mar 28, 2022 8:03 am

Dont feel bad .
A common fault with senders.
Is it NOS or repro?

If it is a repro set it aside and try a NOS one and see if it reads correctly.
Pay attention to grounding in any event.

Good Luck

Fil Bonica

Rickf
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Re: fuel gauge not working properly

Post by Rickf » Mon Mar 28, 2022 9:17 am

If it is a repro gauge then it is probably junk but if it is a NOS gauge then see if it stops moving the gauge before you are fully at the top of the travel on the arm. If that is the case then it could possibly be corrosion on the wiper in the housing. I don't have one here to look at but if you can get the housing cover off then it is easy to see how it works, just a brush on a series or wires. If the wires are dirty you could get this problem. If you can't get the cover off but it has an opening spray some contact cleaner in there and work the arm back and forth over the bad spot. even if you cannot get spry in there try working the arm back and forth with it dry and that might wake it up IF it is dirty contact. If it is a broken wire you are out of luck. If the arm is going all the way up before the gauge stops at the 3/4 then I would return it if possible. If not then take it apart and see if you can move the wiper to suit the gauge, you have nothing to lose at that point.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone


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