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I've read a few of the tank removal threads on here, but I haven't come across any good high-level overview of the major steps, nor pictures for a later gas tank.
I've removed all the spare tire junk, siphoned all the gas out that I could, let the car run for 2 hours to try to get as much possible out of the tank and lines (2 hours didn't do it...!?!?), disconnected the battery, & removed the exhaust from the muffler hangers so they hang down a bit to make more room.
I struggled to remove the removable cross-member (lost a socket inside the frame rail for a while, then had to cut a bolt in half that was messede up- sparks and gas tanks are a scary combo) but it's fully loose now.
Specific questions:
Where are the bolts for the straps?
Do you have to remove one or more mufflers? (I've already removed them out of the hanger brackets so they're hanging down lower than normal)
Hose connections- where do which ones come off? -I can cut any fuel lines because I'm replacing them with Earls VaporGuard EFI hose, but I don't want to cut the line to the charcoal canister.
Electrical wires- where?
Yes, I have the AIM, but the quality of the drawings is pretty terrible.
We use a transmission jack to remove the tanks while on a lift. If you remove the fuel door, bezel and the boot, and slightly drop the tank you'll get to the hoses below easier. While if you remove all the items above you can still reach the hoses without dropping the tank, it's just easier if you drop it about 2" then you can reach them easier.
The strap bolts nuts are located in the rear crossmember... if you have the AIM... go to page 390 it shows a great view of where to access them at. Section 8A page 1 shows you a very clear view.
Once you remove the cross member and the strap nuts, you should be able to drop the tank without any issue.
Pretty sure you will have to drop the mufflers all the way down. I had to on my 79. I have the tank out now replacing the sock filter.
Definitely drop the exhaust. It clears up a lot of area. After pulling the the two hangars at the back it's only 6 bolts, 2 at the cross member and 4 at the cat (or pipe as the case may be).
We use a transmission jack to remove the tanks while on a lift. If you remove the fuel door, bezel and the boot, and slightly drop the tank you'll get to the hoses below easier. While if you remove all the items above you can still reach the hoses without dropping the tank, it's just easier if you drop it about 2" then you can reach them easier.
The strap bolts nuts are located in the rear crossmember... if you have the AIM... go to page 390 it shows a great view of where to access them at. Section 8A page 1 shows you a very clear view.
Once you remove the cross member and the strap nuts, you should be able to drop the tank without any issue.
Willcox
Thanks as always, Willcox! I checked the AIM and saw the cross member bolts for the straps; I did NOT expect them to be there, honestly a pretty slick way to do it.
I did not know that I had to remove the fuel door and boot first, I'll do things in that order.
I'm honestly a bit frustrated by the AIM; it wouldn't be that much more difficult to list things like bolt measurements, nor the order of dissassembly / reassembly in the diagrams. They're just diagrams and nothing more; glad I got one fairly inexpensively as had I paid full price I'd definitely feel ripped off.
Definitely drop the exhaust. It clears up a lot of area. After pulling the the two hangars at the back it's only 6 bolts, 2 at the cross member and 4 at the cat (or pipe as the case may be).
I've got an after market dual 2 1/2" exhaust with the Bowtie overdrives cross member so it's even easier for me to drop the exhaust- definitely a no-brainer, for me as it's only 2 more bolts at the diff.
Pretty sure you will have to drop the mufflers all the way down. I had to on my 79. I have the tank out now replacing the sock filter.
The two lines that run down the driver's side are fuel pressure and return and the line that runs back from the driver's side I'm assuming is the line from the evap canister, right?
(I'll cut the two on the passenger's side as I'm pulling them out and I'll be more careful with the driver's side, then.)
Thanks as always, Willcox! I checked the AIM and saw the cross member bolts for the straps; I did NOT expect them to be there, honestly a pretty slick way to do it.
I did not know that I had to remove the fuel door and boot first, I'll do things in that order.
I'm honestly a bit frustrated by the AIM; it wouldn't be that much more difficult to list things like bolt measurements, nor the order of dissassembly / reassembly in the diagrams. They're just diagrams and nothing more; glad I got one fairly inexpensively as had I paid full price I'd definitely feel ripped off.
Adam
You have to remember, the book is laid out in the order the car was assembled... They are just diagrams but keep in mind these were the pages the line workers used (every day) to assemble the car.
While the AIM will show you good pictures, it won't tell you step by step on how to do a job. The factory service manual and supplement will go a long way when combining it with the AIM. For us, we have an unfair advantage, we've done this job over the years multiple times and know the short cuts.
You have to remember, the book is laid out in the order the car was assembled... They are just diagrams but keep in mind these were the pages the line workers used (every day) to assemble the car.
While the AIM will show you good pictures, it won't tell you step by step on how to do a job. The factory service manual and supplement will go a long way when combining it with the AIM. For us, we have an unfair advantage, we've done this job over the years multiple times and know the short cuts.
Willcox
Some folks on here push buying the AIM as if it were a service manual and the first thing a new Corvette owner should buy; some questions simply get answered with "bought an AIM yet? -If not get off the internet and go buy one!" (then you go and buy one and say "jeeze, that's a crappy, old, not-very-useful diagram. Now I need to go back to CF and find some who understands what an internet discussion forum is for and start all over again...".
Adam
Last edited by NewbVetteGuy; 03-27-2018 at 07:53 PM.
Some folks on here push buying the AIM as if it were a service manual and the first thing a new Corvette owner should buy; some questions simply get answered with "bought an AIM yet? -If not get off the internet and go buy one!" (then you go and buy one and say "jeeze, that's a crappy, old, not-very-useful diagram. Now I need to go back to CF and find some who understands what an internet discussion forum is for and start all over again...".
Adam
When I bought my '80 I bought the GM shop manual too. Now that was in August .... 1980. The shop manual has been very useful, but there are a couple short comings. First, electrical systems change very quickly. So I have found some of the electrical diagrams to be wrong. One i needed recently was the electric choke circuit which was wrong. The '81 manual had it right. The '82 went fuel injected so that took care of that. The other issue is that there are a lot of little details that just aren't spelled out. A recent post of mine was pulling out the speedo gear to plan for swapping the differential gearing. Book says remove the speedo cable coupling the remove the retention bolt. Well, where is that bolt? Very hard to see in that area and nearly impossible to get a hand in there. So then it's Youtube to the rescue. For what it's worth.
Cool - take some pictures of this process. I'll probably end up doing this at some point.
What are you doing with the old tank? refurb/replace?
I made a crappy, crappy video. I need to take a few more pictures and them post them over here in a new thread. I'll update this thread when I do.
I was able to remove the mufflers from the hangers and then loosen the connectors @ the diff -I didn't have to take the headers off of the heads nor disconnect the exhaust from the headers.
At first the tank wouldn't fit down between the mufflers but I jacked my jack up as high as it would go and that enabled me to stand the tank up on its skinny end and pull it out underneath the car with the exhaust still partially attached.
-My strap bolts were totally and complete rusted out- the driver's side froze up completely but I didn't quite realize it and I spun the entire strap around about 5 or 6 times and then the thing snapped in two... (I sprayed penetrating oil on it before but I probably should've zapped the thread with a wire brush first...)
The straps seem to be old sold in pairs and mine was missing the rubber anti-squeak pads (tank was dropped back in 2016 to get rid of 12-year-old gas by someone else who apparently never replaced the anti-squeak pads) so I'm going to have to buy a new pair, but they're surprisingly cheap. -Other than that pretty uneventful.
I got all the hardware wire brushed and the top half of the tank wire brushed. Hardware including the removable cross member has all been anti-rust painted and just needs a top-coat.
My Eastwood tank paint gets here on Wednesday and I'm trying to have the tank fully prepped ready by then.
I have a LOT of rust removal to do but there's nothing but great metal underneath so far. -I'll take some pictures around inside the cavity where the fuel tank used to be. Maybe I'll do a iPhone panoramic and post it on FB and link it here so you can really pan around and look at whatever you want in there.
I cut the rubber lines connecting to the fuel out and fuel in as I'm replacing them all; I didn't cut the line coming from the charcoal canister, but I should have as the rubber is just super, super deteriorated and will need to be replaced.
Adam
Last edited by NewbVetteGuy; 04-02-2018 at 02:46 PM.
After siphoning out all the gas, I let the engine run until it died- trying to pull as much fuel out of the tank and lines.
-I also found out why my fuel gauge stopped working a couple months back- the little push-on wire connector that connects to the fuel sender had popped off and was just hanging there. The rubber "boot" around the fuel door was filled with super nasty stuff and I cleaned it out and it seems I got over zealous and popped the thing off. In retrospect that WAS about the time that the fuel gauge stopped working... *Forehead SMACK*!
Tip #1: When removing the gas tank cross-member have one of those magnets-on-a-pole ready. If you're anything like me you'll drop either the bolt or a socket into the frame rail just out of reach.
Tip #2: My Gymkhana steel leaf spring jacks the rear end up high enough that my jack fully extended won't quite reach the bottom of the fuel tank; have some boards at-the-ready.
Adam
Last edited by NewbVetteGuy; 04-02-2018 at 02:44 PM.
After siphoning out all the gas, I let the engine run until it died- trying to pull as much fuel out of the tank and lines.
-I also found out why my fuel gauge stopped working a couple months back- the little push-on wire connector that connects to the fuel sender had popped off and was just hanging there. The rubber "boot" around the fuel door was filled with super nasty stuff and I cleaned it out and it seems I got over zealous and popped the thing off. In retrospect that WAS about the time that the fuel gauge stopped working... *Forehead SMACK*!
Tip #1: When removing the gas tank cross-member have one of those magnets-on-a-pole ready. If you're anything like me you'll drop either the bolt or a socket into the frame rail just out of reach.
Tip #2: My Gymkhana steel leaf spring jacks the rear end up high enough that my jack fully extended won't quite reach the bottom of the fuel tank; have some boards at-the-ready.
Adam
Someday I will have to invest in in a tranny jack or something of that nature. Fortunately, my lack of any good ability to lift the car with the frame more than about 16 inches limits my need for much of a jack. But clearly the rear end and fuel tank and 40+ pound leaf spring all come into needing something, if not a jack. I have found a nice long piece of rope to be ideal. I can rig it the frame and when properly wrapped it can be used to slowly lower these parts and keep them well balanced. Starting and stopping the motion is easy and if a temporary full stop is needed it's just a matter of tying the rope off. It also leaves the floor clear making it much easier to move around.
I used a wire brush attachment on my 18v drill to wire brush the whole tank- for the small, rusty area around the lip where the two halves are welded together I used a dremel stainless brush attachment.
I rocked the tank back and forth upside down to get most of the last bit of gas out and uses a few paper towels to get the last bit of liquid out and dirt and rust bits in the bottom of the tank.
Then I cleaned the whole tank to prep it for paint with oil / wax remover and then with rubbing alcohol.
Taped off the top of the tank as shown in the photo below and applied 2-3 coats of the Eastwood Tank Tone paint. It has SUPER intense fumes but it dries shockingly fast. I think it looks great. It took 1 1/2 cans to paint the whole tank; some reviews online said 2-3 cans so I now have another 1 1/2 cans extra if anyone wants some.
The last photos show the completed tank with the 1982-style fuel pump hanger just fit into the hole. I'll have to get the hanger height and bracket figured out for my Walbro EFI pump and Holley Hydramat and post those pictures, too.
My new straps and anti-squeak pads aren't due here until NEXT week, but I have a lot of rust remediation and fuel line work to do, to keep me busy for a while...
Adam
Last edited by NewbVetteGuy; 04-09-2018 at 01:04 PM.
03-26-2018, 12:56 PM
79 Tank Removal Overview, Tips & Tricks
