Fuel Gauge question...again

aaluck

Well-known member

Equipment
L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
946
771
93
Snowdoun, AL
I have a L4400HST. The fuel gauge is stuck on full when ON and empty whenever OFF..

I pulled both wires off of the sensor and the tank stayed FULL. Touched the wires together and the gauge goes to EMPTY. Apart again...FULL, over and over. From what I can gather this means the problem is NOT with the sending unit.

That being said what is the problem and more importantly how do I fix it!!! (Sorry the question mark does not work on this keyboard).
 

lunasdude

Member

Equipment
Kubota BX1880, FEL, quick con pto, box bld, land plane, flail mower
Dec 22, 2018
55
4
8
Los Lunas, NM USA
I have a L4400HST. The fuel gauge is stuck on full when ON and empty whenever OFF..

I pulled both wires off of the sensor and the tank stayed FULL. Touched the wires together and the gauge goes to EMPTY. Apart again...FULL, over and over. From what I can gather this means the problem is NOT with the sending unit.

That being said what is the problem and more importantly how do I fix it!!! (Sorry the question mark does not work on this keyboard).
Could be (if you're sure it's not the sending unit) the float.
OR could be a wiring issue such as a short etc.
I would start there, trace wires from the sending unit to the dash make sure no breaks etc.
Then I would check the float, then the sending unit again.

The first solution is free, the second $ the third $$.

Hope that helps!
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
30,231
6,395
113
Sandpoint, ID
I have a L4400HST. The fuel gauge is stuck on full when ON and empty whenever OFF..

I pulled both wires off of the sensor and the tank stayed FULL. Touched the wires together and the gauge goes to EMPTY. Apart again...FULL, over and over. From what I can gather this means the problem is NOT with the sending unit.

That being said what is the problem and more importantly how do I fix it!!! (Sorry the question mark does not work on this keyboard).
You've got it backwards, your results of touching the wires together and the gauge moving 100% means it's got a bad sending unit!
 

Mark 99

New member

Equipment
L3901
Oct 3, 2019
12
0
0
Hillsdale MI
I don't know if this applies to your situation but my 3901 had an issue and after parts, troubleshooting, and time I got to the bottom of it. The gauge would not come off the full mark until the tank was over half empty. I discovered the tank was engineered this way. The top of the tank is several inches above where the sending unit mounts so by design that's all that can happen. I believe it was an engineering trade off to be able to stuff a large enough fuel capacity in a very limited space. Pull sending unit attach wire put through range of motion and see if gauge follows.
 

aaluck

Well-known member

Equipment
L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
946
771
93
Snowdoun, AL
You are correct. I had it opposite of what it was and checked again last night. Open=empty, closed=full.

I ordered a generic Bosch sending unit on Amazon for $16.00 (used, like new) and will see if it works. If not, may bite the bullet and spend the $90.00 for the Kubota one
 

aaluck

Well-known member

Equipment
L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
946
771
93
Snowdoun, AL
Quick update.

It turns out that I busted knuckles, contorted my arms and legs trying to reach everything for nothing. The gauge was actually "working". It appears that it must fall below almost 1/2 tank of fuel for the gauge to actually move. Not sure why, but that's how mine works.
 

dlsmith

Well-known member
Lifetime Member

Equipment
BX2230, LA211
Nov 15, 2018
1,235
789
113
Goshen, IN
Fuel gauges and politicians can be believed to be correct about the same amount of the time. Rarely if ever, and mostly be accident.
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
555
83
USA
I really dislike fuel gauges in general. Last tractor I had, the gauge quit and I used a wood stick to check the level......:D
 

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
6,040
3,316
113
Texas
I really dislike fuel gauges in general. Last tractor I had, the gauge quit and I used a wood stick to check the level......:D
We never trust fuel gauges in airplanes. Dipsticks are used when accuracy is necessary. (Fuel does not determine distance or work-accomplished. It only equates to time-in-service.)

Ive determined that in the average useage to which I put my tractor, compactor, RTV, etc., Im burning about X gals/hr. Its a simple matter to note the time on my watch or hour-meter to know about how much fuel is remaining. I keep a log of how/when I use my tractor and what I accomplished during that time. Makes interesting reading months down the road, and has been especially useful when trying to recall when I did such-and-such or performed certain maintenance.

Just a suggestion. Hope it helps.
 
Last edited:

Roadworthy

Well-known member
Lifetime Member

Equipment
L2501 HST
Aug 17, 2019
1,649
526
113
Benton City, WA
There is a float somewhere inside your fuel tank. It could be sticking rather than traveling smoothly down as the fuel level drops. I have no idea how accessible it is in your tractor but I think you'll find your problem there.
 

GreensvilleJay

Well-known member

Equipment
BX23-S,57 A-C D-14,58 A-C D-14, 57 A-C D-14,tiller,cults,Millcreek 25G spreader,
Apr 2, 2019
11,430
4,911
113
Greensville,Ontario,Canada
I set the one in my diesel forklift to say 'empty' when really 1/4 full. If you've ever run a diesel out of fuel you KNOW why !
 

angelo c

Member

Equipment
Couple a wheel barrows, shovels and beer
Dec 23, 2019
49
2
8
Neshanic NJ
We never trust fuel gauges in airplanes. Dipsticks are used when accuracy is necessary. (Fuel does not determine distance or work-accomplished. It only equates to time-in-service.)

Ive determined that in the average useage to which I put my tractor, compactor, RTV, etc., Im burning about X gals/hr. Its a simple matter to note the time on my watch or hour-meter to know about how much fuel is remaining. I keep a log of how/when I use my tractor and what I accomplished during that time. Makes interesting reading months down the road, and has been especially useful when trying to recall when I did such-and-such or performed certain maintenance.

Just a suggestion. Hope it helps.
I got a few hours in a C182m with bags in the tanks...boy were they fun to watch on a long ride....only ever "coughed" when we were on T/O or over water....then the "wrinkles" would let the water loose.....fun.
 

GeoHorn

Well-known member
Lifetime Member

Equipment
M4700DT, LA1002FEL, Ferguson5-8B Compactor-Roller, 10KDumpTrailer, RTV-X900
May 18, 2018
6,040
3,316
113
Texas
I got a few hours in a C182m with bags in the tanks...boy were they fun to watch on a long ride....only ever "coughed" when we were on T/O or over water....then the "wrinkles" would let the water loose.....fun.
LOL. Yep, and anytime youre flying and notice that you are making fuel (increasing or stopped decreasing fuel indications) are a sign of a blocked fuel vent. (The bladder-tank is collapsing.) Mud daubers did that to me once in my Baron. Went-around one night to avoid deer on my grass runway and just as I pulled up the right engine quit! :eek:
The pump simply couldnt suck enough for the increased-power of the go-around.
(Sorry for the hi-jack.). (Thats an aeronautical term too!). :D
 
Last edited:

aaluck

Well-known member

Equipment
L4400HST, Bush Hog 276, RDTH60, Speeco PHD, etc
Oct 9, 2019
946
771
93
Snowdoun, AL
There is a float somewhere inside your fuel tank. It could be sticking rather than traveling smoothly down as the fuel level drops. I have no idea how accessible it is in your tractor but I think you'll find your problem there.
That's what I originally thought but I removed it completely and it is smooth and without any issues. After I reinstalled it I can push it down gently with a stick and it returns to the top of the fuel.