Best tool for this risky cut in metal

[ratface]

access thru the Well
Hello folks, I need ideas on the best tool/method to make a cut in a 2004 Jeep grand Cherokee spare tire "Well". The idea is to cut an access hole thru the well and gain access to replace the fuel pump thus avoiding dropping the gas tank. There are several you tube videos that show where to cut and that pump will lift straight up and out the top side without dropping the tank. A few use an angle grinder but there are risks with sparks and also with plunging to deep as the pump is within an inch or two below the Well. One guy was making slow progress with tin snips but ultimately finished with a grinder. This at least tells me the metal is not terribly thick. I have and oscillating tool that I think would cut with precision and very little sparks but I have never cut metal with one so any suggestions on metal cutting blades are appreciated. I also have air sheers but not sure on how tough the metal will be for them. Looking for ideas for the right tool with minimal sparks. Looks easy enough and have not seen anyone blow themselves up yet, even with a grinder but I don't want to be the first either.

 

[Janicholson]

access thru the Well
Hello folks, I need ideas on the best tool/method to make a cut in a 2004 Jeep grand Cherokee spare tire "Well". The idea is to cut an access hole thru the well and gain access to replace the fuel pump thus avoiding dropping the gas tank. There are several you tube videos that show where to cut and that pump will lift straight up and out the top side without dropping the tank. A few use an angle grinder but there are risks with sparks and also with plunging to deep as the pump is within an inch or two below the Well. One guy was making slow progress with tin snips but ultimately finished with a grinder. This at least tells me the metal is not terribly thick. I have and oscillating tool that I think would cut with precision and very little sparks but I have never cut metal with one so any suggestions on metal cutting blades are appreciated. I also have air sheers but not sure on how tough the metal will be for them. Looking for ideas for the right tool with minimal sparks. Looks easy enough and have not seen anyone blow themselves up yet, even with a grinder but I don't want to be the first either.

Good price Nibbler

Drill a small hole and use a nibbler. A nibbler takes slivers of metal ahead of where the cut is. The action is a shearing motion against an edge protrudind below the cut a quarter inch or so. They cut a notch. They act like a jigsaw for metal. That price shown is very good. No sparks. You will wonder what you were doing without one. Jim

 

[ARC]

Did one in a Dodge Caravan drilled small hole and then used a nibbler to cut rest of hole. I used a manual one so nice and slow no sparks.
https://www.amazon.com/ProsKit-900-...k0vIv_MbIFPMPvmM5FPb5qXkgFBBKjtRoC9kMQAvD_BwE

 

[RedMF40]

You could drill a starter hole big enough for a jigsaw blade and try that if there's room enough to maneuver. If blade's too long you can snap it off the end.

 

[rustred]

I would use the biggest hole saw but don’t think they makes that big. Next is an air nibbler.

 

[DanielW]

I've cut in the fuel tank area with a grinder and zip disc a few times, but probably not something that should be recommended. I'd also recommend a nibbler if you have room to get it in there. Or score it several times (maybe with a grinder zip disc not going all the way through) , drill holes at the corners, and grab with vice grips and rip it out along the score lines. Won't be pretty, but it'll do it.

 

[Mule Meat]

Drill Nibbler. Attaches to a 1/4" impact driver or 3/8" drill.
You can use the "handle" to rotate the bit any direction you choose without the impact or drill getting in the way. By doing so you can cut very tight and precise circles and corners.

Best tool for cutting sheet metal or tin roofing I have ever used.

 

[bc]

I say don't do it. Just jack it up and drop the tank. I'm the guy who will try anything and did it once to a 2004 chevy malibu. Took out the back seat and carefully used a hammer and chiseled enough to cut a flap that I could bend up. Ended up that the fuel pump had foot long lines that couldn't be reached and connected without dropping the tank. As it turned out, it didn't take me long at all to remove the 2 bolts , un hook the fill hose, and drop the tank anyway using a board as a lever to lower it to the ground. Yours has a foot long electrical connector that you may or may not be able to reach even after opening up the spare tire well. I did it long before youtube was available but if you got some that show it works then good luck. Let us know how it goes.

 

[Harold Hubbard]

I say don't do it. Just jack it up and drop the tank. I'm the guy who will try anything and did it once to a 2004 chevy malibu. Took out the back seat and carefully used a hammer and chiseled enough to cut a flap that I could bend up. Ended up that the fuel pump had foot long lines that couldn't be reached and connected without dropping the tank. As it turned out, it didn't take me long at all to remove the 2 bolts , un hook the fill hose, and drop the tank anyway using a board as a lever to lower it to the ground. Yours has a foot long electrical connector that you may or may not be able to reach even after opening up the spare tire well. I did it long before youtube was available but if you got some that show it works then good luck. Let us know how it goes.

You must live in a no salt/no rust area. Dropping a tank here means replacing the straps at a bare minimum, maybe some exhaust components, brake lines, or other unrelated parts, depending on what is in the way. Anything you touch may disintegrate, or get destroyed when you try to unbolt it.

 

[michford]

I've dropped tanks and have never entertained the idea of cutting into one for access to a fuel pump. How do you close the tank back up after cutting/bending and access hole? I live in Michigan so I've dealt with the rusty straps and lines.

 

[Russ from MN]

He's not cutting the tank, but the bottom of the spare tire well to gain access to the tank. I believe most fuel pumps you remove a bolted-on panel on the top of the tank. I did something similar when we put a trailer hitch on our Subaru, I used a hole saw, but I didn't need to worry about hitting a gas tank. If I had to cut a hole above a gas tank, I would put a guide on my grinder so it would just barely reach through the metal that I wanted to cut.

 

[ratface]

Just an FYI, the electrical connector on this pump is long enough to route under the tank and the connection is accessible from underneath, the vehicle has over 200K miles on it so I really don't worry too much about the hole, should be easy enough to seal with sheet metal and some adhesive caulk. For discussion sake there is a ton of rust on the skid plate of the tank as I live in Illinois where it snows and they use salt on the roads. The biggest part of the job seems to be cutting the hole. An OEM fuel pump is under $100.

 

[bc]

Just an FYI, the electrical connector on this pump is long enough to route under the tank and the connection is accessible from underneath, the vehicle has over 200K miles on it so I really don't worry too much about the hole, should be easy enough to seal with sheet metal and some adhesive caulk. For discussion sake there is a ton of rust on the skid plate of the tank as I live in Illinois where it snows and they use salt on the roads. The biggest part of the job seems to be cutting the hole. An OEM fuel pump is under $100.

Got it. I remember the place where I did it the body metal wasn't flat and had ridges, etc. in it for strengthening and was coated on both sides so how a nibbler will work I don't know. I don't remember what gauge that underbody is but it isn't like cutting tin. Think I had an inch or so of clearance above the tank. Good luck and Think about using some kind of grounding wire for the body, tank, and you to avoid and stray static electricity when changing the pump and maybe even disconnect the battery. As an aside, I just learned about the drill nibbler and need to add one to my tool collection.

 

[DanielW]

You must live in a no salt/no rust area. Dropping a tank here means replacing the straps at a bare minimum, maybe some exhaust components, brake lines, or other unrelated parts, depending on what is in the way. Anything you touch may disintegrate, or get destroyed when you try to unbolt it.

I've dropped a few tanks that were from completely rusted-out wrecks. As you say, new straps required, and often have to re-locate them slightly to the side of the old ones and bolt up through the floor as the original bolts will break off or be seized. But I'd still opt for that route on most front-wheel drive cars. But the OP indicates it's a jeep, which probably implies 4x4 and having to drop a driveshaft or axle as well, which makes cutting out the well look more tempting.

 

[RobCons]

I used a grinder with a cutoff wheel to put an access panel in the bed of my Silverado. I was able to get a welding blanket between to tank and truck bed for the sparks. Then welded tabs on the removed section so I could just set it right back in place.

 

[BarnyardEngineering]

I've dropped tanks and have never entertained the idea of cutting into one for access to a fuel pump. How do you close the tank back up after cutting/bending and access hole? I live in Michigan so I've dealt with the rusty straps and lines.

You don't cut the tank. You cut into the floor of the vehicle.

When you're done, you just pound the flap you bent up back down and throw the floor mat back over it. If you're feeling fancy, duct tape the seams.

 

[Mule Meat]

Simple as that. . On the side of caution. Seal the hole to prevent carbon monoxide from entering the vehicle..

Funny when some people need to be put on life support from just hearing about cutting a Jeeps wheelwell to replace a fuel pump. But be the first to suggest cutting a trucks bed to do the same.

 

[Fixingfarmer]

If you do it this way this is what I’d suggest. Step 1 fill the tank full. It might sound crazy but you would rather have a fire than a boom. The more air you take out of the tank if something bad did occur the smaller the boom. Keep fire extinguisher handy. This is also something this time of year could be done outside.
Step 2 what you want to avoid is big sparks or die grinder. If you can slide a piece of tin foil over the pump from the bottom.
Step 3. Sawsall on slow with metal blade it won’t make much for sparks

If you chose to drop the tank the sawsall is also how I get the straps off most things up here

 

[miangus]

They make a metal cutting bit for an air chisel, I have used that tool for cutting open oil filters. I cut a hole in the bed of my Silverado with an air powered die grinder, I used a cut off disk. I was just careful to barely penetrate. Where a face mask and eye protection.

 

[mrhud]

hope its not for a customer