How to drop the fuel tank?

[DanT]

I read on the list that it is "easy to drop the fuel tank" , but I am not sure how to do that? Do you just pull those 2 pins on the straps facing the rear bumper? I have the original shop manual, but have not been able to locate the procedures in there. (Yes, the manual where Fuel system is called "FU", but has no mention of a fuel tank). What section is it in?

This tank has 256 k on it and lives in the northeast. The tank does not leak ( as near as I can tell) but the tree on top of the tank is horribly rusted and is leaking. I slobbered some jb weld on the lines using a headlamp and trouble mirror, while on my back, stuffing a flat hand in that narrow space and losing some skin. The strap bolts on the forward side of the tank are rusted horribly, and I really do not want to deal with them if I can avoid it. But if this tank pulls with those 2 pins on the back side that would be sweet.

Thanks for any suggestions...

Dan

[irowiki]

Fuel tank dropping might be in the Body section. I'm not near a computer at the moment.

[DanT]

Just checked every page in the BO section, but does not show dropping the fuel tank. Just checked EC, Emission Control, and RA, Rear Axle, also. If you are sure it is in here, I am stumped as to where to find it?

[irowiki]

Yeah looks like FU-33 is as good as it gets.

[Petros]

from memory, this is what I did: 1) drain the tank from the removable plug or siphen from the filler neck, 2) remove the rubber seal at the filler neck (some Phillips screws) under the fuel filler door, remove the gas cap and put in a plug (I use a plastic bag wadded up, it keeps dirt from falling in the tank), 3)remove the cover under the rear carpet in the cargo area and unplug the electrical connector, 4) crawl under the rear of the car, support the tank with a jack, and unbolt the front of the straps from the body floor (two 12mm bolts if I recall), and than remove the pins in the back of the straps. You have fully remove the straps because they will be in the way. 5) lower the tank just enough to get to the fuel lines and either slide them off (difficult on an old car) or cut them and plan on replacing them.

Than you should be able to it all the way out, you have to jocky it some to get the filler neck free from the tunnel, you may also want to soak all of the screws and bolts in penetrating oil (ATF is the best, but PB or LPS also works).

You might check if you can get to the leaky part of the tank from under the rear hatch, not likely becasue it is not very big hatch.

It is actually not that hard, but rusty fasteners can be the most troublesome.

Good luck.

[DanT]

Thanks very much Petros. That step by step will be extremely helpful.

Hmmm... my original '83 paper shop manual only goes to FU-32. I do not think FU-33 ever existed in this '83 book. I checked the 85 electronic version I got from this T4 site, and indeed FU-33 and FU-34 shows the fuel tank diagram in that version. Excellent, very helpful.

You guys rock!

[lannvouivre]

I am going to be dropping the tank soon and will try to remember to take pictures.

Bonus: Black widow infestation 100% guaranteed!
Un-Bonus: Black widows are not actually very aggressive, so it won't be that dramatic.

My usual tactic is to be under the tank of a car and use my shins to support it, then straighten my legs to lower it to the ground. Due to the spiders I mentioned, I might not do this because I'd hate to get sick and miss work!

[Petros]

that bad? you might hose it down with soapy water first, should clear most of them out.

why do you have to lower the tank?

[irowiki]

Black widows? Phew.

[lannvouivre]

that bad? you might hose it down with soapy water first, should clear most of them out.

why do you have to lower the tank?

I want to put the electric fuel pump up near it where the floorboard angles up, that way the pump isn't likely to get hit on anything. I was going to do it near a frame rail, but one of them is horribly dented and that makes me feel like it's too exposed. The tank will be in the way of the drill.

[DanT]

I have been avoiding this nasty job, but it appears likely that I will be dropping the fuel tank this weekend (fuel line no longer supplies fuel to engine, see below.)

Given that my 3 metal fuel lines coming out of the top of the tank are rusted, and I have been patching the return line with JB weld there (and it is still leaking), I expect the need to replace this part, but cannot find it. ( "Vent tube" in attached '85 manual diagram, "fuel tank pickup line" in auto part listings, or "sending unit".)

Where can I get a "fuel tank pickup line"? Do I also need to find a new gasket?, suction tube filter? Anybody done this before?

Condition:
My fuel pump is working fine, but the pump is no longer able to draw fuel up from the tank on the supply line. (Engine runs fine with new fuel lines hooked to fuel pump for supply and return and dropped into a can of gas.) Weird thing is that I can blow bubbles in the fuel tank from the inlet hose entry at the fuel pump, but I cannot suck fuel from the tank to the fuel pump, (Seems like there is air entering the system somewhere), and the fuel pump will not draw the fuel either.

I learned that the engine will run for about 6 minutes after filling the carb with the fuel pump from a gas can... and those supply and return lines work fine. I even swapped the lines back and forth to my real fuel tank... with the fuel pump running continuously... hoping that the fuel pump would draw fuel from the tank when running continuously for 6 minutes... but no go.

I will open the lines at the junction next to the tank next to see if I can draw fuel to the pump from there forward. If so, the only place left to cause trouble is above the tank.

Thoughts and suggestions appreciated.

Thanks,

Dan

[dlb]

do you have compressed air? if so, i would disconnect the hoses from the tank and blow them out each way. it's possible there is a piece of crap in there acting as a one-way valve, which would explain why you can blow into the tank from the pump but not the other way around. that would be my first step before replacing anything.

[Petros]

there are short sections of rubber fuel lines at the fuel filter, if those are old and cracked they will suck air rather than fuel. And act like you are describing, check those first, and the filter too.

if the flex hose or the metal fuel line are old and cracked, either can cause the fuel pump to suck air rather than fuel. if you have rusty fuel lines that is as likely a place for a leak as the rubber flex hoses. I have found that the rubber fuel lines around the engine tend to get brittle and crack being around the engine, rather than the flex line coming out of the fuel tank. So I would make sure you had no leaks anywhere else before I dropped the tank. It is possible you are leaking over the tank, but that would be the last place I would look.

[rer233]

Had a similar problem 15 years ago with my now departed "Old Gold." The car would run for a while and then crap out due to lack of fuel. I tried blowing out the feed line to the fuel pump (no change.) The car was was REAL rusty so I figured the steel feed line must have a pinhole in it somewhere. I replaced the steel feed line with copper line I got from a refridgeration supply company (a LOT easier to bend than steel.) I think it was 1/4" or maybe 5/16". It was a PITA- I ran it thru all the original hangers but never had another problem with fuel supply.

Good luck- hope this helps.

[DanT]

Thanks for the helpful advice. Excellent idea to use copper line. Petros was on the right track to suggest a hole in the line somewhere.

I found the problem. I disconnected the supply line in front of the tank. The front section was airtight to the fuel pump. Dropped a line into a gas can and was not surprised when the engine ran perfectly from that source.

Not so going back to the tank though. The problem is coming from the holes in the rusty supply line that enters the tank from above. After connecting a new hose extension I could not suck fuel out of the tank. Also, as I blew into the tank I could feel air escaping in the back of the assembly above the tank with my other hand. And if I blew hard enough I could feel wet fuel in the back also.Clearly time to drop the tank.

I am still not able to find that fuel tank sending unit. Might be fabricating those lines when the tank is down. If anyone knows where I can get that part, please let me know.

Thanks again for all of the help. Greatly appreciated.

Dan