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I temporarily pulled out the fuel sending unit to take a peak at the interior of the tank, it seems ok but I noticed the intake tube of the sending unit didn't have a strainer. For a late 70s 98, what do you suggest using?
Did the strainer deteriorate and fall to pieces in the bottom of your tank? I suggest using the OE fuel sending unit. I doubt they're reproduced though. You might have to get your's rebuilt.
Did the strainer deteriorate and fall to pieces in the bottom of your tank? I suggest using the OE fuel sending unit. I doubt they're reproduced though. You might have to get your's rebuilt.
I couldn't tell, I can take another look at it this weekend. The unit itself looked really clean. Is it possible to use a strainer that's "close enough" to the original part and put it over the inlet tube? Or does it need a full rebuild because of the missing sock? When I started it a couple months ago I didn't pay attention to the gas gauge so I'm not sure yet if the unit as a whole is still good. It's going to be a few weeks before I'm able to start it up again to know.
If you're going to go through all the trouble of dropping the tank, just put in a new sending unit, and you're good for another 50 years. Rockauto has SpectraPremium (among others), which is a great brand, for less than $50.
You don't say what year your "late '70s" 98 is, so this is for a '79 98.
You can take them apart, clean the contacts, and reassemble. Not a major problem. If you replace it, you'll need to know whether you have a fuel return line or not. I.E., 3 tube vs. 2 tube unit. If you have a 2 tube unit, you can just cap the return line on a 3 tube unit, but you can't go the other way.
You likely have a 3/8" hole-sized sock on it. Although the socks are discontinued from GM, you can get them cheap from Jeg's.
GM p/n 5651702, aka Delco TS1000.
Specs of the TS1000 sock: it is 4-5/16" long, and the hole is for 3/8" tubing. It's nominally about 0.360" roughly which means a fairly tight fit for the tubing.
Closest I've found is a 3/8" x 5.00" long sock. At Jeg's for fairly cheap. #78538 for the part number. The opening for the tube was a tad larger than the Delco one, probably due to the stamping of the hole. It's got more of a flanged hole than a stamped through hole. Hard to describe, but there are slits in the flange that is pushed in during the stamping on the Jeg's unit but not on the Delco. The Delco seems to be a hair better on quality. The hole has a nominal diameter of the Jeg's unit is 0.363", some places just a hair larger, but should generally fit the tube and remain tight when installed.
The sending unit shouldn't need replacing if the tubes aren't corroded and the unit still works. As stated, you can take the float level cover and clean the contacts for the rheostat. But if it's still working and in good shape, just send it. Check the rubber gasket though for cracks/potential leaks. It's fat enough to just squeeze in your hand and check for cracks. Gasket (o-ring) is GM p/n 3893116 superseded to 22515965.
As far as the missing sock, it doesn't have much effect on the sending unit, unless it clogs the tube. It just lets debris/dirt get sucked up into the fuel pump. The sock is just a gross pre-filter for the pump, and the carb filter is your fail safe. Of course without the sock, it can be more problematic for the fuel pump and carb filter.
Last edited by 69HO43; June 17th, 2024 at 06:51 AM.
I will say this for the sending unit. If the current one works, I would keep it if it is original. That would mean it was made in the USA. A new one is going to be made in China. That is what I would do. I bought a sending unit sock a few years ago. There are several listed on Amazon.
If you're going to go through all the trouble of dropping the tank, just put in a new sending unit, and you're good for another 50 years. Rockauto has SpectraPremium (among others), which is a great brand, for less than $50.
You don't say what year your "late '70s" 98 is, so this is for a '79 98.
It says it's for 24 gallons, is that the size of the tank it was meant to go with? Admittedly I'm a bit skeptical about aftermarket part durability, granted they can't always be avoided but my default tends to be avoid them as much as possible. Is that brand any good?
Originally Posted by 69HO43
You can take them apart, clean the contacts, and reassemble. Not a major problem. If you replace it, you'll need to know whether you have a fuel return line or not. I.E., 3 tube vs. 2 tube unit. If you have a 2 tube unit, you can just cap the return line on a 3 tube unit, but you can't go the other way.
You likely have a 3/8" hole-sized sock on it. Although the socks are discontinued from GM, you can get them cheap from Jeg's.
GM p/n 5651702, aka Delco TS1000.
Specs of the TS1000 sock: it is 4-5/16" long, and the hole is for 3/8" tubing. It's nominally about 0.360" roughly which means a fairly tight fit for the tubing.
Closest I've found is a 3/8" x 5.00" long sock. At Jeg's for fairly cheap. #78538 for the part number. The opening for the tube was a tad larger than the Delco one, probably due to the stamping of the hole. It's got more of a flanged hole than a stamped through hole. Hard to describe, but there are slits in the flange that is pushed in during the stamping on the Jeg's unit but not on the Delco. The Delco seems to be a hair better on quality. The hole has a nominal diameter of the Jeg's unit is 0.363", some places just a hair larger, but should generally fit the tube and remain tight when installed.
The sending unit shouldn't need replacing if the tubes aren't corroded and the unit still works. As stated, you can take the float level cover and clean the contacts for the rheostat. But if it's still working and in good shape, just send it. Check the rubber gasket though for cracks/potential leaks. It's fat enough to just squeeze in your hand and check for cracks. Gasket (o-ring) is GM p/n 3893116 superseded to 22515965.
Good catch about the O-ring, I forgot about that. The tube on the sending unit looked clean, no corrosion on the outside at all. Thanks for the input. When I get everything back together I'll know whether or not it's working correctly, especially now that I know how much gas is in the tank.
Asking if the Spectra Premium brand is good is like asking if the Pope is Catholic.
Spectra Premium is one of the best aftermarket brands out there. I have put Spectra Premium brand fuel tank sending units into three different cars, a '67 Delta 88, a '73 Delta 88, and a '78 Toronado. All were drop-in replacments, and all have worked fine.
Spectra Premium is a Canadian company, with the parts made in Canada, so we can avoid the dreaded "made in China" syndrome that afflicts to so many people these days. Yes, Chinese-made components can be of poor quality. So can parts made elsewhere. As has been noted many times, sometimes you have no choice but to buy made-in-China parts if you want a new part because that's all there is. This is particularly true for brake parts.
Anyway, that's not the case here. Buy one of these, put it in your car, and never worry about the fuel gauge again. I never have.
June 15th, 2024, 11:24 AM
