P30 Gas tank removal and rust

[30kdays]

Trying to remove the gas tank due to some rust issues. We are having a hard time getting the tank off the bus and need advice on treating the rust. (We've had success with vinegar)

We have disconnected hoses from inside.
Removed electrical plug for fuel pump.
Disconnected filler and vent
Removed 2 of 4 bolts that hold the bands to the truck.


Do you need to remove all 4 bolts of the bands that hold the tank or just two? The back two closest to the rear end seem impossible to remove with all the rust on them.

[Njsurf73]

Originally Posted by 30kdays

Trying to remove the gas tank due to some rust issues. We are having a hard time getting the tank off the bus and need advice on treating the rust. (We've had success with vinegar)

We have disconnected hoses from inside.
Removed electrical plug for fuel pump.
Disconnected filler and vent
Removed 2 of 4 bolts that hold the bands to the truck.


Do you need to remove all 4 bolts of the bands that hold the tank or just two? The back two closest to the rear end seem impossible to remove with all the rust on them.

i don't know about the gas tank removal, but if its anything like a light truck, there should be straps and usually you need to support the tank while taking the straps off, a piece of plywood on a jack works well and draining the tank as empty as possible makes it easier. just watch out for any wiring for the sender and if equipped electric fuel pump. For the rust you can use OSPHO (name brand) or rust converter. I believe its phosphoric acid that converts the surface of the metal to an oxide that is stable to paint. works similar to vinegar, but better!

[roach711]

Phosphoric acid does a great job of converting rust to iron phosphate which makes a good base for paint. Ospho is a good name but anywhere that sells paint should have something similar. Look for "rust converter" on the can and "phosphoric acid" in the ingredients.

I just gave my rusty oil pan a good going over by using a spray bottle to saturate the rusty areas with the converter then primed/painted the next day.

Spray the rusty bolts with penetrating oil for a few days then try loosening. If that doesn't work try heating the nuts (and avoiding heating the tank) and try again. Worst case, cut the bolts and replace them.

If you try heating the bolts make sure the tank is closed up so you don't ignite fumes and create another BIG problem.

[BlackJohn]

I have an rv on the P30 frame. The gas tank is as big as a bathtub being a 454 engine. Had it off without much trouble taking all 4 bolts off to drop it without a fight onto boards and then jacked it down.
Suggestions above seem ok. An angle grinder used to cut into the bottom of the bolt and or nut. Cut halfway thru and. then break off with a hammer and chisel. Of course support the tank well before you start.
Hope this helps, bolts and nuts are cheap so go new.

[30kdays]

Originally Posted by BlackJohn

I have an rv on the P30 frame. The gas tank is as big as a bathtub being a 454 engine. Had it off without much trouble taking all 4 bolts off to drop it without a fight onto boards and then jacked it down.
Suggestions above seem ok. An angle grinder used to cut into the bottom of the bolt and or nut. Cut halfway thru and. then break off with a hammer and chisel. Of course support the tank well before you start.
Hope this helps, bolts and nuts are cheap so go new.

Sparks flying around a gas tank worries me a little.

We tried filtering the gas with a diy fuel filter I made, but ended up pulling the tank because the fuel pump quit working. It looks like there was a mouse's nest on top of the gas tank where the fuel pump sits. Good thing we removed the tank because the wires to the fuel pump were chewed up.

Can I just order a replacement P30 gas tank? There was a model number on the tank that pulled up on google and it just seemed to be a standard P30 tank.

[30kdays]

Originally Posted by BlackJohn

I have an rv on the P30 frame. The gas tank is as big as a bathtub being a 454 engine. Had it off without much trouble taking all 4 bolts off to drop it without a fight onto boards and then jacked it down.
Suggestions above seem ok. An angle grinder used to cut into the bottom of the bolt and or nut. Cut halfway thru and. then break off with a hammer and chisel. Of course support the tank well before you start.
Hope this helps, bolts and nuts are cheap so go new.

Does your RV tank look the same as mine?

[30kdays]

Originally Posted by Njsurf73

i don't know about the gas tank removal, but if its anything like a light truck, there should be straps and usually you need to support the tank while taking the straps off, a piece of plywood on a jack works well and draining the tank as empty as possible makes it easier. just watch out for any wiring for the sender and if equipped electric fuel pump. For the rust you can use OSPHO (name brand) or rust converter. I believe its phosphoric acid that converts the surface of the metal to an oxide that is stable to paint. works similar to vinegar, but better!

Can I use this on the filler and pipes leading to the gas tank too? They are all full of rust. I'd prefer to just order all new parts. Is that going to be impossible to find? The part number on the tank is 15643250

[Njsurf73]

Originally Posted by 30kdays

Can I use this on the filler and pipes leading to the gas tank too? They are all full of rust. I'd prefer to just order all new parts. Is that going to be impossible to find? The part number on the tank is 15643250

I can not say about how available parts are, but if it's not rusted through, you can treat and paint anything and extend its useful life.
I am sure with the amount of p30 around, there are parts. And filler neck and tubes are probably jelly bean parts. Lots of platforms probably share many common parts.

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[EastCoastCB]

Originally Posted by Njsurf73

I can not say about how available parts are, but if it's not rusted through, you can treat and paint anything and extend its useful life.
I am sure with the amount of p30 around, there are parts. And filler neck and tubes are probably jelly bean parts. Lots of platforms probably share many common parts.

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Agreed, hit up the junkyards, should be plenty of parts.

[30kdays]

Originally Posted by Njsurf73

I can not say about how available parts are, but if it's not rusted through, you can treat and paint anything and extend its useful life.
I am sure with the amount of p30 around, there are parts. And filler neck and tubes are probably jelly bean parts. Lots of platforms probably share many common parts.

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How do you paint the inside of a gas tank? I've never herd of this. Won't gasoline eat away any paint?

[EastCoastCB]

There are tank coatings meant for using IN the tank to seal it up.
People use em a lot on mopeds since the frames are also often the tanks, too.
One that comes to mind is called "Kreem".

[Njsurf73]

Ahh the inside. I misunderstood. There are coatings for that. Generally you clean it out, have it steam cleaned, and put the coating in and seal it up, then rotate the tank put it in its side, upside down. Have done it with a small tank once (5 gallon) and it worked well. Another option is to measure the tank and find one that fits.

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[30kdays]

So is the general consensus that finding a replacement tank will be hard to find/too expensive? This tank is FULL of rust all the way to the filler. I don't think the cap was on very well while it was parked.


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[Njsurf73]

Originally Posted by 30kdays

So is the general consensus that finding a replacement tank will be hard to find/too expensive? This tank is FULL of rust all the way to the filler. I don't think the cap was on very well while it was parked.


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I think you could probably find a replacement tank, but we are trying to give you options in case it's not readily available or cost prohibitive. You can have anything fabricated. You could have an new steel or aluminum tank made to your exact specs, with opening for sender and fuel pump, but it may be a better option to search for one in better condition from another vehicle or to rehab yours. Sitting for any period of time less than full... Or even full (gas is very much like a solvent) will cause the tank to deteriorate.
How many gallons does it hold?

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[30kdays]

Originally Posted by Njsurf73

I think you could probably find a replacement tank, but we are trying to give you options in case it's not readily available or cost prohibitive. You can have anything fabricated. You could have an new steel or aluminum tank made to your exact specs, with opening for sender and fuel pump, but it may be a better option to search for one in better condition from another vehicle or to rehab yours. Sitting for any period of time less than full... Or even full (gas is very much like a solvent) will cause the tank to deteriorate.
How many gallons does it hold?

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I see, thanks for all the help! We sure do need it! I'm at a total loss for what to do here. After spending two weeks filtering rust out of the tank I'm ready to fix this the right way. If the right way is to treat the stock tank somehow then I'm all for it. The rust just seems to be bad inside the tank. It hold about 30 gallons. It was stored with about 18 in it.

[Njsurf73]

Originally Posted by 30kdays

I see, thanks for all the help! We sure do need it! I'm at a total loss for what to do here. After spending two weeks filtering rust out of the tank I'm ready to fix this the right way. If the right way is to treat the stock tank somehow then I'm all for it. The rust just seems to be bad inside the tank. It hold about 30 gallons. It was stored with about 18 in it.

Just sent a pm. I searched GM p30 fuel tank and tons of them popped up.


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[30kdays]

Originally Posted by Njsurf73

Just sent a pm. I searched GM p30 fuel tank and tons of them popped up.


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I've found several too, but none with the fuel neck like mine sticking out of the top. The part number on my tank is 15643250

[Njsurf73]

Originally Posted by 30kdays

I've found several too, but none with the fuel neck like mine sticking out of the top. The part number on my tank is 15643250

Is the fuel neck connected? For 65 bucks for a 40 gal tank, you could have someone add the filler in the right place for pretty cheap.


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[30kdays]

Originally Posted by Njsurf73

Is the fuel neck connected? For 65 bucks for a 40 gal tank, you could have someone add the filler in the right place for pretty cheap.


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It's connected

[Njsurf73]

Originally Posted by 30kdays

It's connected

Look at the last link I sent, it looks very similar. Cost about 135, but that's not too bad.

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