(Help) Factory Aux Tank Removal

[neteng01]

Hi All,

Well, I seem to have hit my first real road block here....

I am just about ready to remove my bed on my 72 C20 Custom Camper. I have most everything removed and disconnected with the exception of the Factory AUX bed tank. (pictures attached) According to one of my local Chevy experts, you need to use a ratchet extension type tool and loosen the 3 mounting bolts that run all the way up through inserts in the AUX tank up to rounded bolt heads with oblong washers between the slats. So my dilemma, I sprayed my trusty liquid wrench solution to help break the frozen bolts free, let it sit for a while and gave it a shot. The result was the tool started to strip out the head of the flat threaded inserts on the bottom of the tank. So, I stopped and decided to ask the powers that be if there are any suggestions to doing this properly and as easily as possible.

I asked the expert once I hit this block and he "suggested" I heat up the bed mounted bolt heads and take the tops off them. I have two issues with that, one, there is a gas tank there....two, I am not sure if I can find the replacement bolts and inserts to put it back on. So, there we go...

Any help, suggestions or ideas are very welcome!!! As always, much appreciated...

[blakeaz33]

I had to grind off the tops of the 3 rounded off heads that you show on the shot of your bed floor. I used a 4" hand grinder with a 50 grit disk, the tank will drop down when you get the 3 head ground down to the oval looking washer. The tank will drop so you may want to put a floor jack underneath to lower it down to avoid messing anything else up when it drops.

[neteng01]

Thanks Blake, it may be the only solution as you state. I mean it has been on there for quite some time I can imagine. What did you do when remounted? Or did you? I am guessing I can find some form of after market bolt and insert, or maybe just long carriage bolts with washers and nuts on the bottom, but I would rather keep it as correct as possible... If I can that is. I appreciate you sharing your experience, at least I know I am not the only one to have the challenge here..LOL

[blakeaz33]

I just left them out because I didn't want them and they hadn't been used for some time on the truck I had - once you get them out and take a look would be simple to get whatever new hardware would work best for you to remount them. They're alot heavier that you would think, the one's I removed were made of some pretty heavy guage material.

[SS Tim]

Sounds like you don't have an assembly manual. Need to get one along with both a factory service manual and a factory overhaul manual. Even if they are beyond what think you will ever need them for its good to have them for reference.
So that said there is no way that penetrating oil is ever going to get there as you are doing it. Your options are limited. Grinding or drilling the heads out, trying to drill out the "nuts" (#8) (which were torqued 20-30lbs-ft on assembly), or try drilling into the spacer between the bed and the tank and flowing a lot of oil in.
Now, I tried to get the rusty stems out of a set of loose cut off aftermarket tanks and gave up after a year of flowing, sitting and pounding.
At this point and if you are trying to reuse parts I would try to drill out the nut/washer (#5) from the bottom. The nuts could then be soaked from the inside and a nut tacked to the bottom to break them loose from the tank. It would be easy enough to put a threaded sleeve back in and reweld the drive hole to square it back up. New bolts required, but then you are going to need them as they are likely about rusted away anyway.

[neteng01]

Thanks Tim,

Ya, I have the manuals and all, and they have served me very well up to this point, but very good and sound advice. I was hoping my only freeze point was corrosion at threaded sleeve\tank bottom. No such luck as you have pointed out. I am finally coming to the acceptance that a grinder and some custom efforts as you describe will probably be my best bet. IF, I can save the threaded inserts once soaked when I can see the entire bolt (after grinding off) then maybe I can fashion the bolts with some descent replacements. But I hope that I am not getting too far ahead of myself as I still have not successfully dropped the tank without wrecking other important parts. A floor jack, some keen patience and a lil luck may save me yet on all but those finicky bolts...LOL.

Thanks again for the tips and excellent advice. As a computer guy, I always look to experience for the lessons learned with least amount of chaos, but when it comes to old rusty bolts, it is often better to just reboot and write a work around.. LOL