Please help fuel guage not showing proper fuel levels

[Diseazd]

All you need to do to replace the sending unit is to tap off the lock ring.....remove sending unit and O ring. Slide in new sending unit with new O ring and tap on lock ring......hook up wires. If reversing the wires fails, check for current to unit. If that fails order new parts (readily available) and install.

[Reverend]

My old Volvo 745 had a funny issue. When driving the fuel tank "fills up" by it self. It was always funny to watch when pointer started to rise in the middle of highway all the way up. Hope you'll get it fixed!

[raltz]

yup i replaced my sending unit and all works now, thank you everyone for all your help!!!

[tlorber]

Just out of curiousity, how empty does the tank [actually] need to be in order to pull out the sender unit and not have gas pour out?

[DatsunDoug]

This is almost always the sending unit, or a bad electrical connection at the sending unit. I have never seen a early Z gas gauge go bad!

[Bonzi Lon]

Just out of curiousity, how empty does the tank [actually] need to be in order to pull out the sender unit and not have gas pour out?

If you are trying to change out the sending unit while still in the car, I would suggest the tank as low as possible, say 1/4 tank or below. If you drain the tank before working on it you will get some of the gunk from the bottom of the tank. When refilling after being drained dry you will need at least 3 gallons of fuel to get to the bottom of the pick up tube.

Bonzi Lon

[tlorber]

Thanks for the input.

[raltz]

i had completely drained my tank, and removed it from the car, more work than just leaving it in the car, but made it easier to work on,

[Jetaway]

If you are trying to change out the sending unit while still in the car, I would suggest the tank as low as possible, say 1/4 tank or below. If you drain the tank before working on it you will get some of the gunk from the bottom of the tank. When refilling after being drained dry you will need at least 3 gallons of fuel to get to the bottom of the pick up tube.

Bonzi Lon

1/4 tank sounds about right for low enough, but since the only reason to be screwing around with the tank sender is that the gas gauge isn't correctly displaying how much gas is in the tank, determining when you have a 1/4 tank left is not all that easy because, well, the gauge ain't going to tell you.

I don't know about the 3 gallons needed to reach the pick up tube. I drained and dropped the tank to get at the vent tubes and didn't put in more than 1 gallon, probably closer to 1/2 a gallon when I was done and had no problem starting up and running over for a fill-up. I have an electric pump (mechanical pump was removed) mounted by the tank on my '72. If you have only a mechanical pump, maybe it needs the extra pressure created by the extra gallons to get going.

Chris