Remove rusted hardened pin from cast housing

The pin is a clevis pin, with a head on it, right?

How is the pin retained (before it rusted in)?

I doubt that the pin is very hard. I would try warming everything up with a torch then douse with penetrating oil and let it sit for an hour or so.
Perform multiple cycles, maybe 10 over a couple of days. Concurrently, try drilling and tapping the pin, 3/8-24 if you can. Thread a stud into the pin. place a short length of tube or pipe over the head of the pin/stud. Use a nut on the stud (over a plate with hole) to draw the pin out.

The pin may loosen during the drilling and tapping process if you get a few heat/oil cycles on it.

To your original question: the hole grows more than the pin (for parts with the same CTE).

PS: Your OP did not describe the actual circumstances well.
 
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Thank you all. I will try heating up. I will focus on the pin and let it radiate outward. I wiil start with butane; if that does not work I will switch to oxy-acy. I have a digital themometer and will limit the cast arm rise to 500 degrees F. That should prevent any damage to the cast arm. I will spray the joint area with PB Blaster at the end of a heating cycle.
There is sufficient space, gap, between the head and the clevis to insert a wedge. I have ground a wedge tool from an old nail puller that fits in the gap between the head and the clevis. I will use that to try to brake it loose.
 
If that does not free the pin up, you can drill the center of the pin out, this will relieve the tension on the pins outer walls and make it easier to remove.
 
In automotive applications where a stud breaks off in a flange or anywhere for that matter, if you can get at the end easily, the best way to get it out is to weld a nut onto the stud. It superheats the stud but leaves the flange or whatever cooler, and it usually comes out, or your weld breaks and you repeat the process.

I thought it counterintuitive at first thinking the smart way was to heat the housing or flange and expand it around the stud, or pin in this case and remove as the outside expanded. I have used this technique many times with success after i finally got past my mental block and tried it.

I also got a hint from a friend who builds heavy equipment. If you have to heat something around a broken or seized part to remove it, he says don't try to heat the whole thing evenly, rather just heat one part of it. He claims it works as well or better that way. I have not tested this yet, but I bet it works because broken equipment is his life and he knows a lot of things, and can build anything.
 
The good news is that the materials involved appear to be forged steel, not cast iron. Looks like a brake can on a truck or similar. I would first try the acetone/ATF mix, if that fails, then I would heat the pin to red, and cool with a dripping wet rag. It should pop right out.
 
Is this a front air brake chamber? Heat the pin with a torch and use an air hammer with a pin punch adapter.
Martin
 
Those parts are steel. No cast iron worries, heat won't hurt 'em, but you want to get in and out quick, as there's a rubber diaphragm on the other end of that pushrod. The clevis and pin kit is under ten bucks, and the clevis or the pin (probably both) is gonna be out of spec by the time you get it apart anyhow. How much do you want to save on what looks to be a steering brake?. Cut it.

What is the failure here? Why does the pin need to be removed? Which parts need to be updated?
 
Yes, it is an air brake part. When air pressure is applied to the brake chamber it pushes on the rod, the clevis, and the pin. The pin then pushes on the arm that rotates the S cam rod and the brake shoes (not in pix). The pin is supposed to rotate in the 'arm' - it does not. I am a new owner, this may have been seized for quite some time. When I discovered it the anjustment mechanim had tried to compensate for the lack of rotation.
My largest concern is the integrity of the arm. I am glad to hear it is forged and not cast. A forged part should have a greater tolerance to head.
My second concern is the integrity of the rubber in the chamber. This could be inconvinient but is a straigthforward repair. I will apply more solvent and then more heat.
Thank all. Dan
 
The pin goes through the yoke, and through the slack adjuster, and there is a bushing in the slack adjuster, that may or may not be frozen to the pin. Does the slack adjuster (in between the yoke ears) have any "wiggle" there? If the pin is frozen to the yoke, but not frozen to the slack adjuster, it's not a problem.

Absolutely and categorically, slack adjusters DO NOT respond to any lack of rotation, in that pin or anywhere else. They ONLY respond to over rotation, and it's referenced by that bracket clamped under the nut that retains the chamber. That bracket interfaces with an arm on the slack adjuster. Although there are exceptions, usually there are no "settings" to that, it just needs the bracket as it's fixed reference. What exactly is the brake doing? Or not doing? Do you know what size the chamber is? Have you by chance found any tags or markings on the chamber? It'd be a type (type 20, type 24L, or any tags or stamps indicating a stroke length? Sometimes around the clamping band, sometimes on the body, sometimes on a tag that's affixed around the port that has the brake hose attached. And by a long shot, do you know what type of brakes are on the axle?
 
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