Gas Tank Removal Questions

[Jim85IROC]

I've got to pull down one of the gas tanks from my 87 GMC 3500 pickup. The rear hanger has rotted half away, and the tank is moving around a little bit. I did a search and some say that it's easiest to remove the bed first, and others say it takes 20 minutes from underneath. That's quite a vast difference in philosophy there.

Anyway, I got underneath and started looking around. Where the hanger is bolted to the frame, it looks like a ridiculously tight fit between the frame and the gas tank for me to get a wrench up there on the nuts. Plus, the nuts are rusty as hell and look like they'll break as soon as I try to turn them. This is starting to look like it's going to be a much bigger project than I had anticipated, so I want to get some advice from guys that have done it before.

What approach do I take here? Even if I remove the bed, I don't see how that's going to help me get the front strap off... that's under the cab. Is there something obvious that I'm missing here, or do I have to get some sort of extra long wrench and try to get it on those nuts between the tank and frame and use a ratchet to try and turn the bolt on the inside of the frame? That just looks like a recipe for disaster to me.

Anyway, any help will be greatly appreciated. Thanks

[ureckme]

There are 4 bolts that go through the frame on each brackrt. take them out and the tank comes down. But first the filler neck needs to be unbolted from the bed. Matt

[us111]

that's the easiest way,,unbolt the brackets that the strap attaches to.you will find the nut's on the inside of frame....

[Jim85IROC]

Originally Posted by us111

that's the easiest way,,unbolt the brackets that the strap attaches to.you will find the nut's on the inside of frame....

Somebody must have already messed with this then, because on mine, the nuts are outside the frame, and it looks awful tight to get a wrench up in there. I can't wait to start breaking bolts.

[beaterC10]

What nuts are talking about, the ones for clamping the straps? If its those, you don't need to mess with them if you remove the bolts that attach the brackets to the frame and pull the tank down with the brackets attached. The nuts for the bolts that attach the tank hangers to the frame are welded to the hangers.

You also need to remove the bolt that attaches the ground strap from the sender to the frame when you drop the tank. The wire is crimped to the sender, so it has to come off at the frame.

I replaced the hangers, tank, and cover on my stepper this summer and pulled the tank loose with the brackets attached. The worst part of the job was reaching in through the wheel opening to remove the fuel lines. I did mine with the bed attached. I think pulling the bed would be more work than dropping the tank with the bed attached.

[us111]

sorry,i said it a little backwards,,beater is correct,,there are "two" L shaped brackets attached to the frame.the "nut's" are welded to the bracket's.,,also the straps are connected to these bracket's..on the inside of the frame you should find "eight" bolt's,,, "four" per bracket holding the bracket's to the frame,,,if you remove all 8 bolt's the entire gas tank,strap's,brackets and all hose's can be removed,,but before taking all the bolt's out be sure and disconnect all hose's like everyone has suggested..good luck

[piecesparts]

Impact wrench and exrtensions for the socket, then take the tank off without removing the bed BUT the hoses are a little of a game after loosening the tank. I have done it and it works. The bed removed makes the deal easier, but then you have to reinstall and align the bed.

[Captkaos]

I am working on a write-up of this, but here is a picture of the 8 frame bolts you need to remove to drop the tank. You DON'T want to remove the straps.

In a nutshell, drain the tank (a low as possible), pull the filler/vent hose, put a jack under the tank with slight pressure, remove the rubber fuel lines from the frame lines (or selector), remove the ground strap,

[Jim85IROC]

Thanks for the pics. I'm going to have to get back up in there and look again. I thought it looked awful tight between the frame and the tank to get a wrench on those nuts to drop the whole assembly.

[Captkaos]

Based on what you are telling me I think you are talking about the strap nuts/bolts which you DO NOT want to remove. You want to take the 8 bolts marked with red arrows out.

[bigarmzz]

wow...nice write up and pics


this should be a sticky

[Captkaos]

Originally Posted by bigarmzz

wow...nice write up and pics


this should be a sticky

Thanks, but this isn't even the write-up. It will be published on 73-87chevytrucks.com when I am done. I had to drop the tank to replace the electric fuel pump.

[Jim85IROC]

Originally Posted by Captkaos

Based on what you are telling me I think you are talking about the strap nuts/bolts which you DO NOT want to remove. You want to take the 8 bolts marked with red arrows out.

I think that I understand that the whole bracketry and tank need to come down as a unit, but my problem is that those bolts you have arrows pointing at have nuts on the other side of them, between the frame and tank, and I don't see how to get my wrench up there. Unless those nuts are welded to the brackets, turning those bolts without a wrench on the nut isn't going to do me much good.

[SSC's76]

Originally Posted by Jim85IROC

I think that I understand that the whole bracketry and tank need to come down as a unit, but my problem is that those bolts you have arrows pointing at have nuts on the other side of them, between the frame and tank, and I don't see how to get my wrench up there. Unless those nuts are welded to the brackets, turning those bolts without a wrench on the nut isn't going to do me much good.

They are tack welded or cast into the bracketry depending on year model ect. All you need to do is what Capt said and the tank will drop right on out.

[Captkaos]

SSC's76 is correct, they are welded to the bracket.

[piecesparts]

Go for it and see what happens....

[us111]

hello,,just wondering if you got it out??? the 8 bolt's and hose's are all you gotta worry about,,,follow "capt" instruction's and you should not have any trouble.......

[GM72K10]

Just did this R & R in my 85 K20. These instructions are the way to go!

[Jim85IROC]

ahh... now it makes more sense.

Us111, no, I haven't gotten it out yet. I just got my truck back from a garage on Thursday, and I've been gone all weekend. I had it at the garage to get a front axle u-joint replaced along with some rear brake work, because frankly, I didn't feel like doing it. Some things are just easier to hand off, especially when you're only paying $20/hr in labor.

With christmas coming up, I'm not sure when I'll get time to tackle it, but now that I know that it is indeed as easy as it seems, hopefully I'll have time to get the tank down some friday afternoon that I'm not working. I'll be sure to post my results here.

[Jim85IROC]

My apologies if this is double-posted. I posted this once already, and can't find it anywhere. I probably posted it in a different forum since I was surfing two sites at once.

Anyway... I've got 2 new gas tanks for my 87. How do I get the old ones down? Do I cut the straps and slide them out or do I need to unbolt the brackets and drop it all together? I looked up there a couple times and it seems like getting to the bracket bolts will be extremely difficult. If I do have to get those out, how are they bolted in? Is it a nut & bolt through the frame, or is there a nut welded to the frame so that I only have to worry about the bolts that I see?

This truck has seen its share of winters, so everything is very rusty, so before I go breaking everything in sight I want to have a good game plan. Should I plan on pulling the bed off the truck so that I can get to things easier?

[Jim85IROC]

Hehe. I found my other post. I had it open in another window but never submitted it.

[Tink]

Unbolt the brackets and drop it all together... the nuts are welded to the frame. The bid thing that is a HUGE PITA is getting to the lines. I'd recommend removing the bed, if you can.

[Jim85IROC]

I've been thinking about removing the bed to put some sort of rust encapsolator on the frame, so perhaps I should just plan on doing it all at once.

[albertgen]

What is the size of those bolts that hold the gas tank? I am going to replace my gas tank and I thought I would replace the bolts with stainless steel bolts. Thanks, Al

[xtreme80]

It can be done without removing the bed, but be prepaerd to be huddled under your truck in awkward positions for 30 minutes at a time while you try to get the lines off and back on again. Then expect to be sore from it for hours after, and also taking breaks every 20 minutes or so because the gas fumes coming off the tank while you're crouched under there will nearly make you sick after a while.

Ive dropped my tank twice, and it was 10 times easier when we pulled the bed first.