| Author | Message | ||
     Panshovevo |
Any secret to getting these out? Trying to get the pads out of the '08 to clean them up, but can't get the hanger pins to move. The outboard side has a 5mm hex socket head, but I can't get it to move, even with repeated soakings with PB Blaster on both ends, and tapping the Allen wrench with a small hammer. I don't have a 5mm impact driver bit, although I probably better get one. | ||
| Kruizen |
Use the 3/8" socket Allen head bit with a breaker bar And Keep the caliper attached to the fork, when loosening the pins. | ||
| Stevel |
This never happens if you use anti-seize on the screws. This always happen in aluminum. For many, many years now, when I take possession of a new bike, I always remove coat and re-install every exposed screw before I ride it the first time. | ||
| Panshovevo |
Finally...what eventually did it was repeatedly heating just the pins in a spot welder and quenching them with PB Blaster, then reinstalling the caliper on the fork to hold it, and using an extension on the socket head wrench. Stevel, that's good advice for hardware that isn't already frozen, but no help for something already stuck. Edited to add that the theory behind heating the pins is that the expansion of the pin helps break up the corrosion formed around it without heating the caliper to the point where the seals were damaged. (Message edited by Panshovevo on September 24, 2015) | ||
| Zac4mac |
Spot welder was your best choice IMO. Dry ice is a fun quench, use welders gloves.  Z | ||
| Stevel |
Yes, my advice does not help after it happens. This problem is electrolytic corrosion caused by the dissimilar metals in the presence of ingressed water. Aluminum is very reactive. This problem is unavoidable without sealing the threads from water. As the aluminum oxidizes the aluminum oxide expands many times its original aluminum un-oxidized volume creating the bind. Heat works better in steel, but not so much with aluminum. The best tool in this case is the use of an impact driver. One hammer strike CCW and then the next CW. Repeating this several times will eventually dislodge the screw without causing screw failure. Once the screw is removed, re-taping the thread and a little compressed air should resolve the issue. However, it's a crapshoot if there is sufficient thread material left afterwards. Good luck. | ||
| Zac4mac |
Steve Great idea, never heard or thought to rock it with an impact but can imagine that works well. Same deal with magnesium if not worse... Z | ||
| Panshovevo |
I've sometimes broken stubborn bolts/ nuts loose with an air impact by using the reverse/forward/reverse technique. Never gave any particular thought to how or why it sometimes works, but it sometimes does. Pure 1100 aluminum is very corrosion resistant. In it's native state, it will form a thin surface layer of oxide, and that's it. When you add alloying elements, it becomes harder/stronger/stiffer/whatever, but also becomes much more susceptible to corrosion. | ||
| Panshovevo |
Duplicate post (Message edited by Panshovevo on September 26, 2015) |
