Note: I used the wrong terminology - these are “caliper pins” that I can’t get out...
Remember if you use heat it doesn’t have to be
red hot, just enough to cause expansion.
Those are always overtorqued in the field. They do not have to be gorilla tight, they are locating pins, not attach bolts.
There is another tool that will work, but I have never seen them other than in an aviation maintenance shop. It is called a screw knocker, and fits on a rivet gun or air impact hammer. The proper size bit or socket goes on the end, and it is turned with an open end wrench while hammering on the stuck fastener. It works where nothing else will.
Heh - too many replies to respond to each...
Vehicle = 2008 Ford Explorer. Front brakes need new pads.
Are the caliper pins threaded only near the hex head? Then I “may have a chance.” But if they are only threaded near the hex head, I am amazed they’ve not freed up: I’ve been hitting these things with PB Blaster every few hours for 3 days (started Fri. afternoon), hammering them each time I went back to the vehicle, and I’m using a breaker bar...
I also tried hammering the end of the breaker bar, but it proves impossible to keep the socket on the pin’s shallow hex head: If I keep trying I’ll “round” the head and not be able to get anything on it. :-(
The hex heads are to the inside of the wheel well: There is some clearance, but I don’t think I can get my impact wrench into position, especially for the top pin. I just bought a longer swivel head breaker bar and will try that, but again there is the problem of keeping the socket on the head, if I’m “out at the end” of the breaker bar. (This also obviously applies if using a pipe to increase leverage.) Maybe I can somehow clamp down the bar & socket to the hex head of the pin? Hmmm...
Drilling out the pins would take a right angle drill, it appears, and lots of time, as there’s no way I can see to get good pressure on the drill bit to the hex head, using a right angle drill.
I assume the neoprene boots are easily available — need to check — as heat may be the only answer... One flexible (rubber-ish) brake line is close to the top pin head.
It occurs to me that my pin heads being shallow makes them “pinheads”.
Oh. No idea how to deal with those. I suggest whiskey - as in drop the vehicle off with a good mechanic, go to a bar, get a few whiskeys, Uber home, then retrieve the vehicle when he or she is done.
You compress the cylinder in small steps with a C-clamp, taking any pressure off the rotor in order to remove the caliper from the bracket holding it. Caliper pins are threaded at each end, and should (even at OEM install) have thread lube to prevent the lockup that can happen from the vast amounts of moisture, heat, road salt, sand etc from causing the threads to lockup on either end. The “pins” are smooth in between and these allow the “travel” of the pads within the caliper as they wear. These should be lubed with HT lube (spec).
Agree with the 1/2 Auto transm. fluid 1/2 acetone dilution loosening fluid and let it sit re-wetting it several times, and with light tapping to increase laminar flow (what is called capillary action down/between the threads and the bracket’s threads. Should work, no need to heat up— the bracket’s had plenty of heat (not red hot, of course) from braking. Don’t be in a hurry.
Stupid question but if they’re pins then turning them will do nothing - you have to drift them out ... ?