The Stovebolt Site Forums The Shop Area General Truck Talk Screw removal

So I'm looking for some old school mechanic's tricks on this one.

I need to replace the gas tank sending unit on my 59 Apache. The problem is that at some time in the past someone completely rounded out the sockets on the tiny (I'm guessing 6-32 maybe) button head screws that are holding it in place.

I've tried everything I know to get them out. Started with a few rounds of Kroil to prep them. Tried Easy-outs (really misleading name in my opinion). I've previously had success with left handed drill bits catching and turning small screws out. No luck this time. I filed a slot in the head of one of them to try a flathead screw driver. No joy there either. I didn't think it's a good idea to grind on them, being that gasoline is on the other side.

I know some of you have been around the block........a few times. I'm hoping someone's got one of those ingenious old school tricks. If not, I'll just have to increase my patience and keep at it.

Try cutting a screwdriver slot in one and use one of those hand held impact drivers.

If I was you I'd remove the tank from the truck and empty ALL of the gas out, then fill it full of water before you blow yourself to the moon. Everything your doing could cause a spark and ignite the fumes in the tank...better to be safe than sorry.

Mike B

I've had that problem. (Per Mike, fill with water.)
Drill out the screw. Tap bigger, open sender flange hole, use next larger screw.

If the area around the tank hole is thick enough, abandon the screw, tap a new hole next to it and drill new clearance hole/slot in sender flange. It's got a gasket and no pressure and is on top. So it's just for splash out, if vented cap is good. No big seal deal.

There are some welding ideas, but not for me.

A new tank is $150. Wonder if that is less stress?

Put Argon, Nitrogen, CO2, or even exhaust gas into the tank before cutting or grinding on the screws, and keep it flowing the whole time you're working with them. The inert gas will displace all the oxygen in the tank and make it perfectly safe to use a Dremel tool or something similar to cut a screwdriver slot in the screw heads. Make sure the slot and the blade of the driver you're using are a very close fit. Then try tightening the screw slightly before backing it out.
Jerry

Jerry, I have had success with slightly tightening screws and bolts before backing them out. My question is, why does it break when you try to loosen it first, but the same bolt doesn't break when you tighten it slightly?
Does it have something to do with tensile strength versus some other property?

Not sure it'd help in this case since it's already reamed, unless you slot it again, but I've had terrific success with 50/50 mix of acetone and tranny fluid as a penetrating oil. Dirt cheap comparatively but very effective. Screws and bolts not moved in 65 years just comin out. Sometimes a little help with mild heat too, but of course using other mentioned methods to rid explosive gases first.

Thanks guys! At the risk of sounding stupid, could using an Easy-out or a file really be an explosion hazard? The Easy-out and left handed drill bit have been used with a tap handle, so there's no heat build up. I used a hand file for making the slot because of the same heat/spark concerns. I'm just trying to understand because I thought I was using a good amount of caution. Thanks again for all the inputs!

How about this: JB Weld another hex head nut or bolt onto the stripped screw and use that to back the original out?

I believe that a person doesn't force it as much when tightening. The material is not stronger in righty than lefty. The tightening/loosening is merely "rocking" the rust or corrosion to break the "bond" loose.

FC, it's the initial hole you drilled, with an electric/cordless drill, for the easy out. Even that should be OK but possible spark. The other things you speak of are just fine.

JB weld does not have that kind of shear strength.

IF you can fill the tank with inert gas or water:

Take a thin piece of copper sheet and punch a hole the size of the screw head (if its exposed, or if its broken off make the hole the size of the bolt/screw itself) and place over the offending item like a bib.

If the screw is broken off flush or below the surface of the hole you can use your mig (or whatever)to fill/build up on top of the screw and the copper 'bib' will help keep things 'contained' to the hole.

Select a nut that just fits over the head/shank and fill that sucker up with a healthy dose of mig/tig or the gas weld of your choice.

Select wrench that fits nut.
Remove offending item.

IF you can't fill the tank with water or inert gas then don't try this on a gas tank

This works great when you've tried (and broken off)easy outs in the frozen bolt/screw. Turn that "OH Fudge" moment into solid success.
No Easy outs? Sacrifice an old tap.
Run an old tap in there till it breaks off and weld it in place, add the nut and away you go.

Being in your situation daily as a airline mechanic,I have stuck to a strick approach with any type of fastener.
SCREW SLOTTED: hit it with aerokroil or another penetrating oil.Let it work its magic for a bit!.Dab coarse valve grinding compound on the head and screw bit tip.
Use a 1/2 drive speed handle! Press down hard with your shoulder and snap it in reverse with a quick force.
HEX head or ALLEN slotted hardware:Same as above but if the head corners are rounded or allen channel is rounded inside,then packing the head with valve grinding compound AND using a metric bit if its sae since you are basically now using a sub-incremented size (remember,its rounded out)
HEX headed bolts or nuts.Pack the socket with valve grinding compount to take up the slop and go for it.Again,since if its rounded off try a metric socket to fit tighter and pack the DAYLIGHTS with VGCompound for grip.
If all else fails,impact hammer or easy out time...

Based on my experience, you're NOT going to get the screws out intact. Mine were rusted where the screws extended thru the shell of the tank, so short of cutting them off inside, there was no way they were going to thread out, no matter how much kroil or whatever I used.

I thought one of mine was loosening, but it was in the process of twisting off. After that, I just snapped them all off and drilled them out. Started with a 1/16 inch bit, then working up till the shell could be picked out. Ran a tap (same size 6-32) thru the holes and they're all good to go.

I like the way this man thinks. I wish I thought of
this so I could say great minds think a like.
Jeffrey

Also, after soaking with the penetrating oil and before attempting removal use a drift of the same diameter, or possibly what ever tool you're using to remove said bolt and rap it with a hammer once or twice, this will help loosen things up per sey.