Fuel Sending Unit

[Andyboy]

I'm replacing my 62 gmc fuel sending unit that has a v6 305. I got my new unit in but the fitting is smaller then the old one. Can I change the hard line coming from under the truck to the tank or should I get another sending unit? Thanks for any info.

[jbgroby]

No go to napa for the adaptor, I just had to do that. Just take the hard line and the sending unit with you, in order to get the correcct size.

[Andyboy]

are you using it aready? I ask because I used an adapter for my other truck and couldn't get it to stop leaking.

[Andyboy]

What if I Change the hard line from the fuel filter to the tank from I think 3/8 to 5/16, and change the inlet fitting and leave the outlet fitting a 3/8. Will that affect any thing?

[jbgroby]

Originally Posted by Andyboy

are you using it aready? I ask because I used an adapter for my other truck and couldn't get it to stop leaking.

I have not tested it, but the fittings are flaired and I also used a bit a teflon tape. It should not leak. ON the other question, you could change it out with a different size tubing but why spend the extra money and go through the BS of bending, the fitting only cost $2.00 I think.

[Andyboy]

Thanks for the info jbgroby, The fitting adaptor was fast and easy.

[jbgroby]

COOL,

Jake

[Surfdaddy]

Did you get a OEM replacement or a universal. I'm gettin mine this Friday and if I have to get an adapter I would like to know before I try and put it in. I already found out he hard way that I needed and adapter when I replaced the rear brake cylinders. This would save a bunch of running around.

[jbgroby]

Sirf,

IF yu are going back with 100% EOM gauges and such, you will need to buy an off the shelf stock unit from ay of the part suppliers. BUT

If you use after market more modern guages you will need to have the OEM Fuels sending unit modified by changing out the resistor.

I bought the modified one from Mayeda Motor Sports. He removes the older 30 ohm and replaces it with a 0-90 ohm resistor. I think he is a member on the board

[Surfdaddy]

I'm planing on staying OE. I'm going to Truck Shop to pick up some of the items I forgot including the sending unit since it's sure to be bad after sitting for 20-plus years with a full tank of gas. These last two weeks has been the trans work then I'll move on to the fuel system.

[Andyboy]

surf, I ordered mine from the truck shop and ordered part number 60-10713. The one for the 60-66 truck, it had the gasket, filter and float. It is the 30 ohm.



I'd get in trouble also if I lived that close.

[jbgroby]

MY credit cards are SO glad I don't live close to them.

[iehotrod]

i PURCHASED ONE FROM THE TRUCK SHOP IN ORANGE CA. AND HAD NO PROBLEMS WITH FITMENT. BUT I STILL DONT GET A CORRECT READING ONTHE GAUGE... HAS ANYONE HAD THIS HAPPEN TO THEM BEFORE?

[Rich 5150 69]

Does your gauge ohm match the sender...? 30 vs 90 in either direction.

[iehotrod]

Dang it I threw the box away. I did request it for the 62 which I understand them are 30 ohm. How can I test it?

[Rich 5150 69]

You can test with a volt ohm meter. Do not exceed 1.5 volts battery power or damage to the gauge will result, test them separate.

[iehotrod]

So I should disconnect the + coming from the gauge and the ground? then place the red cable from the reader on where the gauge wire would go and the black wire from the reader to the ground on the sending unit? It should read what 30 ohms? Sorry I am not tech savy I just remove and bolt on type of guy still learning.

[Rich 5150 69]

Just test each part as a individual, pos to the lead, and gound the neg, remove the tank sender and move it though its range. The gauge, test with the gauge disconected from the harness.

[iehotrod]

Awsome thanks will try it as soon as I get it back.

[Surfdaddy]

I figured that since right now things have been real busy I can buy everything now. But come next month we will finish the projects and everyone will be will be hiding and dodging the grim reaper, since they are talking 37% layoffs. They way things work you eighter have the money or the time but never both. So I'l buy everything while I have the money because pretty soon I'll have all the time.

[Andyboy]

Yeah surf, It's hard everywhere. I'm there now and it's tough. Good luck.

[Andyboy]

OK I hooked everything up and the gauge is still stuck on Full. When I bought the truck It was stuck on full. So Is there something I'm missing?

[Surfdaddy]

Does that mean that there is a bad ground ? I seem to remember something like if the gage reads full and gauge moves when power is applied usally there is a bad ground. either on the gage or the sending unit. However, I may be wrong since I haven't had to deal with this in a very long time. By the way I have the same thing. The gauge reads full eventhough I know there isn't a full tank. that's why I'm replacing the sending unit. I may have the same problem afterwards.

[Surfdaddy]

I got the new sending unit and connected it to the wires and it moves correctly. The fitting is wrong so I'll get teh adapter from either NAPA or Carquest. I would check the wires to the gauge and see if you have a bad connection or you something. Trace them to the fuse box and see what you find. On my tank since it had 20+ yr old gas in it I thought for sure the tank was going to be rusted through but it was like new inside. The thick brass conductor on the sending unit had stressed and cracked and that was the problem with the gauge.

[Andyboy]

That's great, I'm glad it worked out for you. I still can't figure mine out. The needle doesn't move at all. The back of the gauge has alot of wires wraped up, so I'll check the fuse box again.