an archived post that might be of interest:
I found this on another site sounds like cheaper and better fix than replacing
the fuel sender all the time.
Fuel Sender Part #: 04797738, cost is reported to be in the neighborhood of
$40. Expansion and contraction of the plastic tank can wear the pivot screw
slot that allows up/down motion. If the screws were to stick at the upper
portion of the slot, this effectively changes the pivot point elevation of the
sending unit float, causing low fuel readings with half a tank of fuel. After
repeated failures, some have begun experimenting to find a better fix. the
'sliding mechanism' that allows the pickup point to stay at the bottom of the
fuel tank Here is one posted to the TurboDiesel mail list:
Subject: my fuel sending unit repair kit
Some time ago I posted my fix for the inadequately built fuel-sending unit for
our Dodge Rams. I have assembled an instruction sheet and the parts I used to
fix this. I am curious how many readers would like to obtain these kits. I can
send you one for $3.00 postage and handling along with a self-addressed
envelope. Just let me know and I will let you know where to send your request.
Send email request to email@example.com
Here is my suggested fix again if someone missed it.
Out of all the posts that I have read regarding the fuel tank-sending unit I
was wondering if anyone has taken a look at its design. Mine went out and I
replaced it myself, was not too hard to do. After I replaced it with an
identically designed item I took the old one and found out what contributes to
the failure of this part. I will try to explain it and a possible fix. The
plastic pivot arm is held in place on the metal stem by a plastic tab on the
rear edge that wears on the main body of the unit. This wear allows the
contacts on the arm to leave the contact on the resistor that sends the signal
to the gauge. Result is the fuel gauge no longer works.
Either the fuel tank must be removed or the bed of the truck needs to be moved
back for access to the fuel tank module. The fuel lines are removed by
pressing on the tabs of the connector while gently pulling on the fuel line.
Both lines are removed this way. The connector stays on the line going into
the module. They are different sizes so when you reinstall them they can not
be crossed up. The electrical connector is removed by using a small
screwdriver prying sideways and removing the red clip that locks it in place.
On the front of the connector, the module side, there is a tab that needs to
be pressed down to unlock the connector and then it is removed by pulling on
the connector not the wires towards the frame. Remove the rubber hoses that go
to the fuel filler neck and slide them up on the filler neck tube to get them
out of the way. There are two nuts holding the fuel tank straps, remove these
while supporting the tank with a floor jack or anything suitable. Slowly lower
the tank and pull it from under the truck. The module can be removed by gently
tapping on the ears of the retaining nut, with a hammer and punch, in a
counterclockwise direction, making note of its position for reinstallation.
Take care not to damage the rubber seal under the nut as in can be reused.
I noticed on the module, there are three screws that were showing some wear on
the slots that attach the lower part to the upper part. I used three washers
that would fit the shoulder of the screw to reattach the lower part to the
upper part so it would not slide. I measured the nearly empty tank where the
module is installed up to the neck where the retaining nut is including the
rubber gasket and made the module the same length. My measurement was 14
5/16". I could not figure out why this needs to move up and down. In fact this
caused a hole to be chaffed on the return line in the center of the module.
Thank goodness it was not the pick-up line I would have had to replace the
whole module $400 I think. With an empty tank the module will be touching the
bottom of the tank but when the tank is full it will be pulled away with the
weight of the fuel.
Now for the suggested repair action.
The plastic pivot arm has a center stem that extends above the outer body
about 1/8". Remove the pivot arm by carefully prying between the main body and
the rear part of the pivot arm where the tab is. Trim the top of the center
stem of the pivot arm level with the outer body, with a sharp razor, taking
care not to break it. While the arm is off you may want to gently bend the
contacts out away from the arm as to allow for better contact with the
resistor. Reinstall the pivot arm by carefully pressing it back on the metal
stem make sure the holding tab is behind the tapered edge of the main body
where it is held on. Place a Teflon washer on the metal stem with a P-nut, one
of those push on washers that lock when installed. Make sure you push the
P-nut down far enough to prevent the contacts from loosing its contact to the
resistor, taking care not to allow the pivot arm to bind, you can use a small
socket to do this. This will allow the weight of the float to be placed on the
Teflon washer and P-nut instead of the tab on the rear part of the pivot arm.
The metal stem diameter measures 3/32". The float arm can be easily removed
from the pivot arm by pulling it away from the arm on the contact end and out
over the center stem, then when done reinstall after you are done.
I would like to mention C. J. Johansson, which his suggestion was to
manufacture a new pin and machine, threads on the top and use two nuts to lock
the pivot arm down on the resistor. His pictures are very clear and show the
center part of the pivot arm that I trim off.
Install the tank in the reverse order you removed it. Making sure the
module-retaining nut is positioned in the same place it was removed from. Fill
her up and check for leaks!
This should be a better fix than replacing a $42 dollar part each time your
Huey L. C, Jr.
From: Don B
You really can fix it for about one dime!! I just did it and it works so far.
The hardest thing is removing and replacing the tank. Did it alone.