Fuel Sending Unit 79 Aspen CONFUSED

[David Clark]

Sorry for all the questions. I just wanna make sure I do things RIGHT and not WRONG.

So I got the old tank off the 79 Aspy and pulled the Fuel Sending unit off. The Top is fairly rusted but the bottom (inside the tank) is clean. I was contemplating getting a new sending unit but (i usually order 99% of my stuff from Rock Auto) the one listed at Rock Auto for the 79 Aspy does NOT match the one I have on the Car. The one at Rock auto shows TWO tubes coming out of it, Mine has ONE tube coming out of it. and Two wires hookups. Round one and a spade one. (See Pictures). I tried Looking up a Sending unit for a 78 and earlier but they don't have them available. Tried Orielly's Site too and they show the same thing for a 79, the Two Pipe Sending Unit, And Nothing for 78 and earlier. ???

Do ya think it would be ok to just clean up the rust on the Old one and put it back in, It does work, I was just concerned about the Rust issue and the Rust Spreading to the rest of the tank if I reuse the old one.

Also, is there any thing out there that I can coat the new fuel tank with that will help prevent it from rusting all to hell like the original tank did??

 

[slant6billy]

Not sure if the picture is correct. That looks like a vent tube on the one pointing straight down. I think your tank has a vent tube already on the passenger side- correct?. You might be able to use it and just cap off the vent tube. I have mine capped off. I might suggest go with a store you can compare it at the counter- like Orielly's. when it comes in bring in your old one to compare. As for rust in the tank- Stabil has a new fuel additive for the ethanol water corrosion. Look for the gold/ clear stuff in the Stabil bottle. If you are hell bent on reusing the original, try some brake fluid mixed with trans fluid. I found the used fluid cleans up the corrosion. Just only use it on the circle and not the tube, sock, or float. after it is cleaned up use some rust bullet. Hell, I cut to the chase lately and just applied rust bullet and it returned the metal to clean.

 

[David Clark]

Thanks for the input. I have 3 holes on my tank, one for the sending unit, one for the Filler Tube, and one with a small plastic insert that has a hose coming off it (vent I would assume). The Fuel Sending Unit that Rock Auto shows says AFTER 4/79, so maybe mine was built prior to that. All I know is there's just one pipe on mine coming off the sending unit. I'll see if I can get the mass Majority of the Rust off this one with your suggestions.

Any suggestion on what I can use to Coat the tank with (Roofing tar LOL??) to keep the new tank from rusting when I get it on. Do they make a Tank Coating that can be applied to the tank?? I also noticed when I pulled the old tank off, some sort of pad in between the Tank and the Trunk Pan, any thing I can substitute that with without paying the 150 some odd bucks they want for a new pad. Does it serve a purpose other than keeping the tank from vibrating on the trunk pan??

Thanks again for the input. I want to do things Right and you guys are pretty knowledgeable on this sort of stuff (hell I just turn wrenches is all) and want this car to last another good 20-30 yrs after I get it fixed up.

 

[Aspen500]

It appears the extra tube is for a fuel return line. Most likely the kind that comes out of the side of the filter on some vehicles (my '81 Dodge truck was like that). My '79 was built in June of '79 but the sending unit I got (for the after 4/79) looked just like the original, but I bought it over 10 years ago. If you have the plastic roll over vent valve in the top center of the tank, then you have a post 4/79 production car. Pre 4/79 was a vent tube soldered to the tank and the roll over valve was near the right cowl area on the back of the rocker panel.
That extra wire with the eyelet is a ground (not like original). Mine has the ground wire on the flat terminal on the unit itself.
So,,,,,,,,,,I have a feeling that sending unit is made to fit with any engine and 49 state or California emission (maybe?), and they added the ground wire as a "problem solver". The return line tube can just be blocked off with a fuel resistant rubber plug and you'll be in business if you're not worried about 100% stock appearance.
I see this all the time at work. Replacement parts are made to fit as many years and models as possible and sometimes there's extra tubes, or wires, or etc.....and you use the ones you need and block or tape back the ones you don't.

 

[slant6billy]

When I moved my tank last summer for the ability of dual exhaust. I did not reused the insulator pad. I used a plastic cushion pad cut down. As for rust prevention- use rust bullet. 45 bucks a quart, but worth it

 

[David Clark]

Thanks for the Clarification, I do understand that some parts are made for many different applications, but some, while almost identical, aren't really the same. I've got my sending unit (the Top flat part) soaking in some Vinegar Right now to hopefully knock off some of that rust, it's deep on that thing, hell the pad I pulled out from between the tank and trunk pan was Drenched in water and funny thing is, it hasn't rained up here since we got the thing. Must not be very good ventilation on that Pad.

Thanks for the Suggestion on Rust bullet, will look into that. Deconstructor Jim is to be mailing off my Trunk Pan this week through Greyhound so hopefully by next week I should have it and be able to get it in.