Air Conditioner bolts

[Chuck]

I'm trying to remove the plenum on the inside of the trailer so that I can take down the ceiling panel. This part of the ac is wider than the hole for the a/c, and squeezes down the main body of the unit to the roof with these very log threaded bolts. One of them came out easy; the other 2 started coming out ok, then stiffened up; can't even move them with my electric hammer drill.
Then I stupidly tried to move one with a cheater bar over my socket wrench handle, and snapped it in 2.

now what?

seems like maybe they were rusty on the top, and as that part of the thread worked down into the hole, it jammed up. I put some PB blaster on there, but I don't know....

[Chuck]

nothing, huh?

I'm wondering if the pb blaster is going to be able to penetrate since it has to go "up";

I'm wondering if the other side of these bolts is accessible from the top. (?). Last time I had the cover off, seems to me that most of the guts of this old Coleman ac were pretty well sealed up; not much to see.

[perryg114]

Is this the original Armstrong AC or an newer one? You may end up having to remove the whole unit and fix the problem. Usually a torch will help break the bond between the bolt and the threads. You will need to repaint the area though. You want to heat the nut or threaded area and keep the bolt cool as possible. Put some vice grips on the broken bolt. Alternatively, you can drill out the bolt with increasingly larger drill bits till all the threads are gone. Sometimes you can save the threads if you don't drill too far. Most of the time, the bolt threads will wrap around the drill bit and come out stuck to the drill bit. The key to doing this right is having a flat surface to drill on and center punch to make sure you are in the cente of the bolt. DO NOT USE an easy-out bolt removal tool or you will be screwed. You can't drill through a broken off easy-out and it will break if the bolt broke.

Perry

[Chuck]

Its a Coleman unit; no idea of its age, or origin.

I just went out and snapped a couple of pics, and tried to move the other bolt, after letting the PB sit overnight, and it still doesn't want to move. I'm thinking that the penetrant doesn't want to penetrate "up" very far.

(I'm taking this down so I can get the ceiling panel down, so that I can get the skins off, so that I can get the endcap off, so that I can remove/replace the smelly old mouse-infested insulation out, as part of the process of replacing the floor that is rotted in the back. )

[perryg114]

Well a sneaky way to deal with this would be to make a threaded spacer and just screw that on the end of the broken stud. Think a big long nut here. It would be easy to make one from some aluminum rod stock. You just drill a hole through it and tap it to the proper thread. I expect it is something like 3/8-16 threads.

If you end up junking the unit I want the fan motor.

Perry

[Chuck]

Originally Posted by perryg114

Well a sneaky way to deal with this would be to make a threaded spacer and just screw that on the end of the broken stud. Think a big long nut here.

Yes!! that would work. You can actually buy those; I think they call them "coupling nuts." Didn't even think of that. (which is why I posted).

Originally Posted by perryg114

If you end up junking the unit I want the fan motor.

Perry

Heh heh. too bad you just fixed it.

(it was working the last time I tried it; amazing, considering the amount of insulation that was stuffed up behind one of the heat exchanging coils by mice. must have been blocking significant air flow. )

now to get the other bolt out, without breaking it.

[perryg114]

Your welcome.

McMaster-Carr

Perry