leaking fuel sending unit

[gbafus]

I've discovered that the gas tank sending unit is leaking on my '58 Biscayne. I'm planning to replace the unit & it's gasket. I have read on other forums that it is difficult to get these to seal properly. Any suggestions would be appreciated. Gas is too expensive to be leaking on the ground! Kinda unsafe, too.:eek: According to my shop manual, it's possible to change the sender without dropping the tank, once it's drained. Can anyone confirm this?

 

[jim_ss409]

I don't know about a 58 but on a 62 you can change the sending unit without dropping the tank. It's a little tricky to get the "o" ring seal positioned right because you can't see what you're doing real well. But it can be done even with as much as 2/3rds of a tank of fuel. But again I'm referring to a 62 model, the 58 may be different.

 

[gbafus]

I don't know about a 58 but on a 62 you can change the sending unit without dropping the tank. It's a little tricky to get the "o" ring seal positioned right because you can't see what you're doing real well. But it can be done even with as much as 2/3rds of a tank of fuel. But again I'm referring to a 62 model, the 58 may be different.

I think they changed the design in '61, but thanks anyway. I suspect it will be tough to see mine to install it, as well.

 

[58impala]

I just changed the sending unit last week on my 58 Impala and it's no big deal. The unit is accessable without dropping the tank. Be sure to drop the fuel level in the tank below the sending unit hole or jack up the front of the car. My new gauge came with a thin rubber gasket but the gasket from the old unit was cork and thicker. Since one of the screws was broken off (tank was rusty, gonna change it out) I decided to reuse the cork gasket. I cleaned it up with lacquer thinner, along with the tank flange, applied some aviation permatex to all surfaces and reinstalled it. Tanks is now 3/4 full and no leaks after a week. Check the new unit with an ohm meter before installing it to be sure it works correctly. It should read about 30 ohms on the high side and about 1 ohm on the low side. Make sure before removing the sending unit that you tape up both wires or disconnect the battery. Any sparks can be a disaster.

 

[gbafus]

Make sure before removing the sending unit that you tape up both wires or disconnect the battery. Any sparks can be a disaster.

Thanks Jim. EXCELLENT advice!!! I would have forgotten that Oh....I'm thinking I'll need to break down & finally buy a set of clutch head screwdrivers. Correct?

 

[58impala]

Clutch head drivers are useful on these old chevy's but my sending unit had phillips head screws and I believe that's the way they were originally. !0/32 screws I think.