73 fuel sending unit leakage/removal/ gasket?

[wa5ngp]

My 73 stock has developed some slight gasoline leakage around the gasket for the fuel level sending unit. I've looked at the arrangement a bit and gotten the wires off. Its not obvious how to remove the sending unit. It looks like a simple twist of that ring will get it loose. This does not seem like a very reliable way of securing something that is holding back a full tank of gas. It looks like if I grab that ring with channel lock pliers it would come loose with about a 180deg rotation. Is that right?

Don

[sblake01]

Turn the ring counterclockwise. It actually holds the sending unit rather securely and there isn't much pressure there. IIRC, the seal is an o ring or at least it is on a 280Z.

[wa5ngp]

Tks Steve, you've given me confidence to try it.

I was conerned that I was missing something. I'll run down the gas tank as far as I can then pull it. There is an old fashioned hardware store near me that has all kinds of O rings so I'm sure that I can find something close.

regards Don

[wa5ngp]

oh, one more question for you, does your 280Z have a voltmeter or ammeter? Have you happened to check the resistance of your sending unit?

Don

Don

[Sailor Bob]

Tip - Hydralics shops carry virtually all sizes of O rings (most anything an s30 might need). I got some for my steering knuckles at a local shop, they had a wall full of them.

[wa5ngp]

tks Bob, I hadn't considered that option. Good thing about those is that they would be more tolerant of petrochemicals too.

Don

[sblake01]

oh, one more question for you, does your 280Z have a voltmeter or ammeter? Have you happened to check the resistance of your sending unit?

Don

Don

280Zs have voltmeters. I've not checked the resistance on the sending unit but this scan should help. It's from the 78 FSM but the setup is the same for all years of the 280Z:




And for the o ring, the Nissan part number is 17342-18000. They cost less than $2 and they were still available about a year and a half ago when I bought one.

[wa5ngp]

tks Stephen,
That pretty much answers my questions. My 240z shows 30 ohms so I suspect its close enough. Now I'll see if I can mod that 280Z gauge to fit my 240z dash. Then I'll have a voltmeter instead of ammeter which no longer works due to my direct routing of alternator to battery instead of thru cabin.

Don