1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Caliper won't come off, rusted to the pin.

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Old Nov 3, 2010 | 02:34 AM
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Caliper won't come off, rusted to the pin.

Doing rear brakes, left side the caliper slides off the pin fine, right side it's pretty much rust-welded. Sprayed with blaster, tried to hammer it off, no go. The pin is unscrewed from the bracket and spins with the caliper.

Any tips on getting it off? Or should I look for a new caliper?
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Old Nov 3, 2010 | 02:40 AM
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Save yourself the headache and just replace the caliper...
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Old Nov 3, 2010 | 02:59 AM
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Yeah, kinda what I was thinking. Sucks though. The caliper works fine aside from the rusted pin. At least new ones aren't super expensive.
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Old Nov 3, 2010 | 03:46 AM
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stick the hole thing in the freezer for a couple days and try hammering it again it my help.

Also try a big ziplock bag of this stuff worked great for me.
http://www.theruststore.com/Evapo-Rust-Gallon-P1C1.aspx
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Old Nov 3, 2010 | 04:04 AM
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I don't think that stuff has the penetrating capability.

Won't freezing shrink the metal around the pin even more?
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Old Nov 3, 2010 | 05:00 AM
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yes but the resulting thaw out will then open up space....its a small thing to try and just might do the trick so why not give it a shot?

IMO its woth the time and bleeding compared to a new caliper

Both of my ideas are cheap and dont require him to do much. if this fales get the rebuild kit and torch the sucker off.
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Old Nov 3, 2010 | 07:21 AM
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I would use a propane torch on it and penetrating oil. The heat/cool cycles will eventually break it loose.

Its a mute point though because unless you hone the cylinder out and sand
down the pin, it will just seize up again. Even then it may still rot once you put
it back together.

Buy a new caliper.
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Old Nov 3, 2010 | 08:37 AM
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if your boot and greese is good there will be no need to replace the caliper rust will ONLY build up if there is moisture in the pin hole which can be stopped with a good boot and good greese.

no need to spend money if you can just do it right.
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Old Nov 3, 2010 | 02:50 PM
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use a map gas torch and heat the area around the slide pin. the metal will expand from the heat and you will be able to hammer it off. replace the slide pin if its extremely rusty and pitted. otherwise you can wire wheel and repolish the slide pin. thoroughly clean teh slider area of the caliper or replace the caliper. use a good quality grease when reinstalling.
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Old Nov 4, 2010 | 12:46 AM
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Propane's good, Mapp gas is better, acetylene is best. You want to get the part hot fast. The longer it takes to heat, the farther the heat spreads during heating and the less effective it is. While it may not make much sense in general, I've found it true in most applications.
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Old Nov 4, 2010 | 02:58 AM
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K, I'll try to torch it, but I've already started to grind down the pin so I can put a wrench on it. It's odd that rear pins don't have nuts on them like the front ones do. I think I'll just end up bying some cheap calipers. Driver side one won't retract. Been spinning it forever - last mm or so: no go. Can spin it out ok, and spin it back in a bit, but at a certain point it just stops retracting. Probably needs a rebuild. Old calipers are old. Meh.

Oh and also I seem to be missing one of the rotor fastening screws. Are those special or can they be had at a hardware store?
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Old Nov 4, 2010 | 03:14 AM
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To bolt the rotor to the hub? Those can be left out if need be. All they do is keep the rotor lined up making it easier to screw in the lug bolts. Hardware store ones are fine, no need for them to be hardened.
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Old Nov 4, 2010 | 12:53 PM
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Ah, word.
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Old Nov 5, 2010 | 02:12 AM
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Well, I got the caliper off finally, just out of principle - to see if I can do it. Ground the sides of the pin flat, put a large wrench on the pin, fixed the caliper to the bracket, and then hammered at the wrench for a few minutes, and broke it loose. Another hour of PB Blaster and working the wrench and I got it loose enough where I could bit by bit slide the caliper off.

It's a rust central in there. Pin itself isn't too bad, but the pin housing is all corroded and pitted. Looks like it goes pretty deep into the metal. Not gonna bother with it.
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