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Rusty gas tank

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Old 06-09-2021, 07:45 PM
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Default Rusty gas tank

What would you guys do if you saw this? Drain and clean? Or just replace with a used or even new unit? I already have a replacement sending unit with pump and all so that's taken care of.



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Old 06-09-2021, 08:07 PM
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I've used electrolysis with excellent results on motorcycle tanks. After the electrolysis I added some phosphoric acid based gel to attempt to minimize flash rust.
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Old 06-09-2021, 09:17 PM
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There are treatments for m/c tanks that involve putting the stuff in the tank and sloshing it around, my son had good results on his RD350 tank. Not sure how you would slosh it around in your tank in situ, but using a paintbrush might work. Citric acid is good for cleaning things up, but you would have to treat the surface afterwards.

Dropping the tank is not a trivial exercise, the diff and rear cradle have to come out, but if you are going down that path anyway I'd get another tank, assuming better ones can be had.
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Old 06-10-2021, 10:49 AM
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Originally Posted by SpartanSV
I've used electrolysis with excellent results on motorcycle tanks. After the electrolysis I added some phosphoric acid based gel to attempt to minimize flash rust.
I've never used electrolysis but have seen people have a lot of success with it. Only issue is the tank would still have to come out

Originally Posted by Gee Emm
There are treatments for m/c tanks that involve putting the stuff in the tank and sloshing it around, my son had good results on his RD350 tank. Not sure how you would slosh it around in your tank in situ, but using a paintbrush might work. Citric acid is good for cleaning things up, but you would have to treat the surface afterwards.

Dropping the tank is not a trivial exercise, the diff and rear cradle have to come out, but if you are going down that path anyway I'd get another tank, assuming better ones can be had.
Yeah I think a new tank might be the best plan, it just sucks having to remove the rear-end, not sure I have the tools to do so. Might need to buy a tranny jack.
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Old 06-10-2021, 11:07 AM
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Originally Posted by SuperTuner12010
it just sucks having to remove the rear-end, not sure I have the tools to do so. Might need to buy a tranny jack.
If you remove the differential first, it's not horrible to drop the rest of it with a standard floor jack and some wood.
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Old 06-10-2021, 11:21 AM
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Originally Posted by Joe Perez
If you remove the differential first, it's not horrible to drop the rest of it with a standard floor jack and some wood.
Thanks for the tip, I thought about dropping it all at once but that would be a pain. I'll do just that and drop the diff first. My issue now being, well the diff is out I might as well just put in some 3.63 gears
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Old 06-10-2021, 11:32 AM
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Originally Posted by SuperTuner12010
My issue now being, well the diff is out I might as well just put in some 3.63 gears
I wouldn't. Not at whatever power level you're getting from 7 PSI on an M45, unless you're looking for a pure freeway cruiser with as-stock acceleration in town. And if that were the case, you'd probably be running a small turbocharger rather than a positive-displacement supercharger.
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Old 06-10-2021, 12:50 PM
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Why do you need to remove the tank for electrolysis?
​​​​​
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Old 06-10-2021, 01:38 PM
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Originally Posted by Joe Perez
I wouldn't. Not at whatever power level you're getting from 7 PSI on an M45, unless you're looking for a pure freeway cruiser with as-stock acceleration in town. And if that were the case, you'd probably be running a small turbocharger rather than a positive-displacement supercharger.
I need to update my signature, I'm in the process of installing a Kraken low mount with a 6258. Just installed a 6spd as well so need to get rid of the 4.3, 3.91 would be a good middle road.


Originally Posted by SpartanSV
Why do you need to remove the tank for electrolysis?
​​​​​
U was thinking to drain the water after it's all done but I guess I could use a pump.
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Old 06-10-2021, 01:54 PM
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Or the drain plug at the bottom of tank
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Old 06-10-2021, 02:31 PM
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Originally Posted by Houleo
Or the drain plug at the bottom of tank
This is what I was thinking.
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Old 06-13-2021, 06:05 PM
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Originally Posted by Houleo
Or the drain plug at the bottom of tank
I didn't see a drain bolt on my tank, I've seen mixed posts on if all tanks do or not. Only thing I've seen is the drivers side of the tank should have a drain but theirs no such bolt I had seen unless it's between the subframe and tank.
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Old 06-14-2021, 11:34 PM
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Fuel Tank Repair Kit - POR-15 (por15.com)

I've used this stuff for a couple of Z car tanks. It's worked well for me.
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Old 06-15-2021, 04:03 AM
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drain plug is hidden underneath undercoating. Look for a lump near the lowest point, hit it with a steel brush. New tank is.. ~$200. We took our rusty-ish tank to the local radiator repair place (increasingly rare but still around), it was $80 for a clean and reseal.
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Old 07-19-2021, 02:17 PM
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If you want a tank, I have a spare from a 90 - and I'm in NM.

Let me know, I can pop it open and check the inside if you're serious.
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Old 08-01-2021, 03:24 PM
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I also had a similar rusted tank. I chose to replace it with a known good 0 rust tank. Took me a 2 buddies about an hour to drop the rear subframe on a lift and unbolt the old tank. My issue was that every time I took a hard turn the pump would get clogged and I'd essentially get fuel cut
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