Rusted tanks

[1978C201964]

Hi guys and girls. Name is Chuck. New to the forum and glad I joined. The pdf files are awesome. I recently bought a dead horse(1978 C-20) and hauled it home on the trailer. After looking it over I found that both 20 gallon tanks were rusted out (non-repairable) . Since then a lot of parts are on order. I rebuilt the Quadrajet (750cfm) and removed the old Edelbrock (600 cfm) from the 454.Now I'm installing the new tank. I just need the truck usable for local stuff so I have no reason to replace more then one tank as of yet. Is it possible to just hook up the one tank and add another later when I can afford it ? I know I could add a rear tank and eliminate the other two, but I'll eventually go back with both side tanks. This is getting costly fast so hooking up just one tank now is all I can afford. Btw, I cleaned out the steel lines and added a 100 micron fuel filter before the mechanical fuel pump. Any help would be appreciated, I'm not a real Mechanic. I mostly lie under the truck to keep the Florida sun off of me.  Added the frame photo after I cleaned/painted under fuel tank mounting area. What is the stamp for ? Added the fuel valves too after tank removal. This was all cut away before i removed it.Any chance I can bypass this equipment and just plumb the new tank in ?

[Mike81K10]

Welcome from Alabama! You can simply cap off the lines used for the other tank for now to include the selector valve. New tanks are a little over $100 and make sure you clean out your fuel lines and tank selector valve. I had badly rusted tanks and my whole fuel system was contaminated with rust and has to be replaced. Some pics of it is on my build thread.

[1978C201964]

How do I access your build thread ? Btw, already bought one tank and a ton of other crap to try and breath life into this beast. The carburator rebuild was my 1st. Made sure to add well plugs and and atp plug to the carb before rebuilding.

[Mike81K10]

Members Rides, 81 K10 Build, and there are many other build by others as well.

[1978C201964]

Thank You Mike .

[Mike81K10]

Post some pictures of your truck. Save your pics as JPEG and adjust size so they are not larger than 500KB. Then click on Attachments and other option and attach. You can edit a previous post and add pictures to previous posts by clicking modify on the post you want to edit.

Once again, welcome to the truck forum!

[1978C201964]

What is this ?

[Mike81K10]

Appears to be an air tank. It appears to be under your truck (is that correct) and is it hooked up to anything? I am very surprised to see your chassis looking like it is in new condition.

 I do not understand why someone used two different (made for different year trucks) selector valves, together? The selector valves make no sense. The one to the left is the type in my truck 81 (used 5 wires from a 6 wire connector), the one to the right my have been original to your truck (believe it used two wires grnd and pwr) and someone else in this forum can tell you if that assumption is correct.

[1978C201964]

Like I said, I bought a dead horse. Just trying to breath life into it. I inherited some serious shade tree mechanic stuff. I'm going to attempt to bypass it all and install one tank on the right(passenger)side. Today I cleaned out the return line and re-mounted the main fuel line. Do you see any issues with bypassing it all and just hooking  up the tank ?I can't find a cannister anywhere and assume I will have to add a spring plug to the vent line. You are correct in assuming the tank is under my chassis . It is not hooked up to anything.Just has a plugged 5/8 line . I cleaned the frame with carb cleaner, and scuffed it. Then shot it with a rust inhibiting paint. The frame was just greasy.

[Mike81K10]

Go to Fuel Systems and Driveablity and start a thread for your fuel system build/repair. You will find many knowledgeable people that will provide some really good advice and there are already some posts with wiring diagrams and information that will be helpful. If you can, take pictures of your fuel lines at the tanks and where they were hooked up at the selector valve. Your system will be a little different than my 81 and that is a good reason for you to start a thread in the fuel section where people are familiar with your specific truck.

It is a good start taking that air tank out and I believe the single wire selector valve that was on the right side of the picture was your original valve. You will have a 3/8" fuel feed line, a 1/4" return line and a 5/16" vent line that goes to your charcoal canister. If you want to install just one tank, you should not need a selector valve, the 3/8" and 1/4" lines will run directly to your fuel pump and like I said, your vent line to your charcoal canister.

If you need a fuel tank, you can get one for about $130.00 from Tanks Inc. They are a very popular place to buy fuel tanks and other needed fuel system parts.
https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=282/category_id=64/mode=prod/prd282.htm

As I said, starting a thread under the Fuel Systems and Driveablity tab would be your best option and I will look forward to seeing it in that section.

[1978C201964]

Thank you for your time.

[Mike81K10]

Your welcome, continue to update your progress, provide pictures and if needed ask questions. If I cannot answer them others will.

[Chevygold]

Tank selector valve on the right is the one I have in my '76 Cheyenne, think it's power on for one tank and off for the other tank, I've just had both my tanks off as fuel filter kept clogging with white powder like cement, not sure what it was but only one tank was affected, renewed all the hoses while they were off as well as they looked like the originals and were showing signs of age, well worth doing as having experienced one car fire I don't want to go there again!!

Good luck
Graham