Fuel Tank Removal "How To"

[esmit208]

ARGNIEST

It sounds like your biggest concern is re-installation. If that is the case take tie on tags and mark all the connections as you undo them, either A,B,C,D,etc or 1,2,3,4,etc. When you get the new hose which won't be much lengthwise re-attach those before re-installing the tank. The marking method is a can't wise technique. It's not always practical to have a service manual or pictures next to you when you are on your back with tons of road crap falling in your face. In additon to wearing goggles KEEP YOUR MOUTH CLOSED. I would also suggest installing a fuel filter between the tank and the pump if possible. Solid material will also cause a fuel pump to fail.

[ezzzzzzz]

I'll chime in if I may. All suggestions are good. It is a easier to have help but many of us don't have that luxury. I would drive the car until it was nearly empty before starting this job. Drain the rest using the plug in the bottom of the tank. Even a few gallons of gas is heavy and very awkward when it starts to slosh around. Clearance is a big issue. You should jack the vehicle up until you can get jack stands under front and rear. The alternative is to jack it high enough to get car ramps under all four tires (with the ramps facing forward). That will provide you with plenty of working room. Be sure to set the parking brake and test for stability! The later S30 is easier than a 240Z because there are less hoses. Don't forget the small feed and return hoses and the fuel level wiring. I think stock hoses are still available for a small fortune. I used marine fuel hose material for mine. Don't forget to replace the grommets where hoses enter in vehicle cabin.

[FastWoman]

All good advice.

With regard to hoses, I'd just get the generic fuel-rated stuff, unless you want to be a purist about everything being all-original. There are a couple of formed, woven larger hoses (the 5/8 variety). The longer one has to make a couple of turns that are somewhat tight, hence the pre-formed bends. A non-purist solution to this is to get a couple of 5/8" Goodyear EZ-Coil doodads to go over generic hose. They're stainless steel slinkies that slide over the hose and hold its form in a tight bend. Also make that hose just a bit longer, so that it can make gentler bends. It's not a particularly expensive job when done this way.

I bet ezzzzz and I bought our marine-grade 5/8 hose from the same place!

Michael, there are lots of people who just replace what breaks and nothing else. There's nothing "wrong" with this approach. However, a lot of us like to replace everything that looks frail whenever it's convenient (e.g. when we're into the job). That saves us from a lot of diagnosis and wrench twisting, although we might end up paying more in parts in the end. Two different philosophies.

Edited February 2, 2011 by FastWoman

[Powderkeg]

Argniest,

I did my tank in September with POR-15 and it wasn't that difficult. It does take about a week because of the need to allow the POR-15 to dry properly. I coated the tank inside and out, replaced all of the fuel hoses, add a Fram G-3 fuel filter between the tank and fuel pump.

Removing the tank isn't that difficult (If I can do it...anyone can). Since most of this has been covered before I'll just give you a few tips.

I did this myself on a gravel driveway. Use ramps, jacks, wood blocks, railroad ties or whatever you can to make sure the car is secure. I had the rear of the car on drive-up ramps with all kinds of support.

When removing the wheel splash panel you will now have access to the filler tube. The filler tube has three screws that attach to the base of the filler tube that is often hidden by mud and dirt. Use a good penetrating oil like KROIL or PB Blaster.

All of the hoses should be available at the local auto parts store. The vent hose with the 180 degree bend is the annoying one. This is the 5/8 " (16 mm) and I had to order this one. You can make the bend by getting a 1/2" stainless steel tube and have a machine or muffler shop bend it for you. The Nissan ones may still be available.

When you install the tank it's easier to attach the filler tube to the tank first then feed it through the filler tube hole. You can heat the tube with a heat gun to help it fit through the hole. It took me about a minute to do this. The filler tube is pretty stout so don't be overly concerned about getting a bit rough with it if necessary.

The tank straps and "J" bolts may or may not be easy to replace if you break them so apply plenty of penetrating oil. I cleaned the bolts and straps and coated the straps with POR-15.

Hose grommets are still available at MSA and other vendors. Or you can use shrink tubing.

The hose sizes I used for my 76 were:

5/8" (16 mm)

1/4' (6.3 mm)

7/16" (11.1 mm)

3/8" (9.5 mm)

Some articles:

Classic Zcar.com:

Search "Gas Tank Breather Hose" Aug 15 05 by Redfive.

"Care in Removing Gas Tank Parts".

Atlantic Z.com:

Tech Tips "Replacing Vent Line Hoses" by Blue.

HybridZ.com:

"Gas Tank Vent Hoses".

Good Luck

Dave Ruiz

[argniest]

ahhhh man thanks so much for all this info!!! WOW. I really want to do this job myself if it is needed. I first want to remove the fuel sending unit in my 1978 (and the inspection plate too of course) and see if I can partially move the fuel sending unit a little out of my way (without disconnecting evyerthing). If I have to remove it, I will. But then I can inspect the tank. I have a nice remote inspection camera with a wireless monitor, so if I can get the fuel sending unit out carefully, I can hopefull see what kind of magnitude of crud is in there!!! Im hoping for a 1, but maybe it will be really bad 10 and full of tons of gunk. I have seen some of the pictures on this forum of what comes out of some of these tanks and it made me gasp for air. I hope mine isnt too bad. Although I do understand about sealing it with POR 15, if mine just was only a little dirty I would be OK to just power wash it out, a little muric acid or whatever is really safe...etc. And then put it back on. I mean as long as it looks clean after that, I would rather just put it back on that way. And some other time, do everything else.

As far as hoses, thanks for the info on them! Im sorry if I didnt see it in the thread, but I would like to purchase all new hoses, just want to be 10000% sure I get the right brand size type. I am always nervous as hell to use any part. Im soooo new to all this stuff, I feel like an idiot.

[argniest]

Can the fuel tank be removed without touching the fuel sending unit. I still havent had time to touch the fuel sending unit, because I am still trying to figure out the leak tester. And to get good readings with that.

So I was sitting thinking if the tank can be removed without messing with the fuel sending unit, that would be a nice bonus. The fewer systems I have to touch the better, at this point. I have a long list of things i am working on, and I dont want to add more to it right now. Springtime is getting closer finally, and I could be less than 45 days from being able to drive again!!!!

[Powderkeg]

The sending unit has to come out of the tank. It's not that difficult. Disconnect the plugs..it'll be obvious where they connect.

There's a collar that you have to gently turn (I've forgotten which direction...see FastWoman's post). And the unit comes right out. Be gentle when removing the unit. Remember how it's oriented so you don't put it in upside down.

Do you have a camera?

You should also replace the round black gasket. They are inexpensive.

The whole process is really not difficult...you'll do fine.

Be grateful that you have a 78 as most of the parts are still available at mostly reasonable prices.

Good luck

Dave Ruiz

[cozye]

The sending unit does not have to come out of the tank. Just unplug the electrical connections from under the access cover in the trunk prior to lowering the tank. However if you are going to have the tank cleaned out, you will have to remove the sending unit at some point.

[FastWoman]

^^^ What Cozye said!

BTW, don't use muriatic acid to eat out corrosion in the tank unless you intend to POR15 coat it afterwards. The tank is galvanized, and the muriatic acid will eat away the zinc.

[argniest]

Thanks for information. I have pages and pages of stuff printed off about the tank cleaning. I hope to find out in the next few days...how good or bad it is.

[argniest]

OK, well I took out the sending unit, well I mean I just took out the retaining ring, and pushed it aside far enough so I can look into the tank. It doesnt look horrible as I imagined it would, but also I see sediment on bottom and it looks dark like rust. I could also stick a very long screwdriver down there and push the stuff around, and feel the grittiness of it. So that seems to confirm the same junk I got in my fuel filter is in the tank. But overall, I can also see parts of the tank bottom that have nothing on it, just the shiny surface. So it seems like maybe there is just this rusty sediment crap pooled up on different places on the bottom of the tank.

But I also saw rust on the metal line that is running across the inside of the tank at the bottom of it. And I touched it with the screwdriver too, and was able to make that rusty looking crud move off the metal line. So it doesnt seem like its on there real crazy like. Just kind of on the surface.

And also, I cant see very far in any direction because the inspection hole is only like 2 " across. I plan on draning all fuel into a container, and taking a sample of it into a glass jar (after shaking up the gas can holding the Z car gasoline and rusty crap in it).

Then I planned on adding some more gas (a little) to the tank, and sloshing the car around a little with my foot on the bumper. And then draining the gas again. That will give me 2 chances to drain some junk out of there. Then once it airs out, I am going to stick and inspection light in there, and see what the top of the tank looks like, and wherever else I can point the camera. Since the tank will be empty and dried out, I see no harm in that or danger. :-?

However, I am still expecting I will have to remove the tank and have my cousin clean it for me, and do whatever other magic is needed. He has done dozens of these before since he restores cars for a living. So he knows what to do, and when to take it to the next level, like steam/boil it, muratic acid, welding in new pieces if any pinholes developed, and sealing it, etc

Soooooooo can anyone tell me how to properly position the fuel sending unit and float back in there. I just want to make sure when I put it back together that its inserted back in there correctly. I know it will be hard to explain in this text box....but maybe someone can Im kicking myself for not paying more attention to what position it was in, when I moved it out of the way. But it was hard to see anyway...since it was such a small hole and you have to move it no matter what.

THANKS

Edited February 15, 2011 by argniest

[FastWoman]

Argneist, I told you to note the position first! (Don't worry. I did the same thing.)

There's an alignment notch on the flange of the sender unit. You'll see. It won't fit completely flat without the notch being correctly aligned.

You can look around the tank with a dental mirror and PROBABLY a well sealed (water tight) LED light. But don't use ANY light that might create any sort of spark!!!!!! Don't dare use anything with a breakable bulb!!!!! If you use a very clean mechanic's mirror (a bit larger than a dental mirror), you can bounce the flashlight off of the mirror to introduce the light into the tank, while still leaving yourself enough room to peer into the tank. A very bright keychain LED light works well for this. (You would hold the light right by your eye, pointing towards the mirror.) , As with ANY light, satisfy yourself as to any spark risk, because you don't want your tank to explode in your face!!! (Note: Gas fumes can explode too, even in an empty tank.) As your tank is mounted to the car, you might have to climb into your hatch to get your eye close enough to the hole to see much. Dunno.

The rust is coming from somewhere. It might be your intake line. They can be prone to rust.

Edited February 15, 2011 by FastWoman