|Brake Rotor Removal for Those Pesky Hex Head Fasteners
Ed: First things first: the bolts that hold the rotors on these bikes just plain suck! They will instantly round off, and they were also installed with Loctite from the factory. Ham-fistedness with the bolt removal will necessitate extracting the stripped bolt from the wheel.
First, heat the bolt and the area of the wheel casting around the bolt hole with propane or Mapp gas. Get it good and hot to expand the hole and melt the Loctite. Whack the top of the bolt with a hammer a few times. Now use an impact driver with a Craftsman or higher quality 5mm socket (not a cheap import socket) and a hammer and impact the bolt loose. Repeat heat/impact until the bolt comes loose. Once the bolt turns ½ turn or so, remove the bolt with your ratchet.
In this case, impact (dynamic torque), and not static torque is your friend.
|Jerry: There may come a time when it is necessary to remove the disc brake carriers on your newer Guzzi, e.g. in order to power coat the wheel or replace a worn/damaged rotor. Since the factory uses special button-head socket-head (Allen) cap screws secured with thread lock, they can be a real bear to remove, and the Allen recesses on the bolts are easily damaged. Here is the right way to do it.
You will need: 1) replacement bolts, from the dealer. These are special made bolts that are not generally available. 2) a high-quality 3/8" drive 5mm Allen bit. Do not try to use the cheap stuff. 3) 3/8" drive impact driver. 4) a 4lb sledge hammer. 5) a reasonably thick piece of carpet, cardboard or other such padding to place in between the concrete surface and the wheel. 6) a heat gun. A hair dryer won't cut it. 7) safety glasses, just in case. 8) a 3/8" ratchet drive.
Step 1: after removing the wheel from the bike and laying it on the floor, don the safety glasses
Step 2: apply heat to the area of the bolt. While it is hot, insert just the Allen bit and whack it good a few times with the hammer. The idea is to use the heat to soften the thread sealant and the blows to break it loose. If you try to use a cheap Allen bit, you may find that the hammering will peen the drive opening such that the 3/8" drive will no longer go into the bit.
Step 3: heat some more, if necessary and then repeat the process with the impact driver. The bolt should break free and loosen. Use the ratchet to remove it while still warm.
If this is done correctly, all of the bolts should come out without the necessity of cutting/grinding. If for some reason this isn't the case, it is best to use a cutting wheel or other such to carefully cut a slot in the head of the bolt and try to turn it out with the blade screwdriver bit on the impact driver. Grinding the head off the bolt will get the carrier off, but then you have to contend with removing the rest of the bolt with vice grips.
Credit due: I learned this procedure while working as a mechanic at Moto Guzzi Classis, from the proprietor, Mark Etheridge, Guzzi Sage Extraordinaire.