1. Remove the seat and left saddlebag. Instructions on removing the seat can be found here, and on removing the bag can be found here. Careful to disconnect the turn signal wire (on top of the rear fender before pulling the bag away.
1. Loosen and remove the caliper pivot bolt.
2. Loosen and remove the lower caliper bolt.
3. Pull the caliper up off the brake rotor and remove it.
4. Unbolt the brake pin retainer bracket bolt.
5. Remove the brake pin retainer bracket.
6. Remove the brake retainer pins. These are frequently seized in place, and may require some persuasion. I used a punch and a hammer to persuade them out from the back side of the caliper. The brake pads will fall out when these pins are removed.
7. Remove the rotor cover retaining screw, then pull the rotor cover up and away.
8. For the next step, I use a simple piece of 1/8" thick steel welding stock. It seems to be the perfect thickness. If you don't have something like this, an old brake pad would work as well.
9. Place the welding stock into the caliper in place of the brake pads.
10. While holding the welding stock in place, have an assistant pump the rear brake pedal. This will push the pistons out of the caliper. Usually one piston is hung up more than the other. Without the welding stock, one piston will come all the way out, leaving the other one hopelessly seized in the caliper. Using the welding stock, the piston is not allowed to completely eject from the cylinder. Once it hits the welding stock and stops, the remaining piston is forced out. Make sure you don't run your brake fluid reservoir dry while doing this - add some brake fluid if necessary.
11. Once both pistons have hit the welding stock, stop pumping the pedal, and remove the welding stock. Pump the pedal once more, and one of the pistons will pop out.
12. The other one should be easily removed by hand. Careful - there will be lots of brake fluid in behind the pistons, and it will come out quickly!
13. Remove the banjo bolt fitting holding the brake line to the caliper.
14. Rinse the caliper and pistons with plenty of brake cleaner.
15. Remove the brake spring from the caliper and clean it with brake cleaner.
16. Push the pivot pin out of the caliper. It is usually fouled and tough to get out. Here I am using a 3/8" socket extension to push it out. Remove the slider pin rubber boots from the caliper.
17. To clean and polish the pistons, you will need two fine grades of sandpaper - 600 and 1500.
18. This piston has corrosion and dirt on it, as well as scoring lines left from corrosion in the caliper.
19. Polish in a circular motion (never in a straight line) first with the 600 grit sandpaper, then with the 1500 grit sandpaper to polish it. After polishing with the 1500 paper, this is what it should look like - it will be extremely smooth to the touch.
20. This slider pin is filthy and corroded. The channels need to be cleaned out, and the corrosion sanded (gently) off.
21. Again, start with 600 grit sandpaper, then polish with 1500 grit, always in a circular motion.
22. The seized brake pad retention pins need to be cleaned and sanded as well.
23. The pivot bolt should be cleaned of all grease using brake cleaner.
24. Very gently, using a small knife or screwdriver, pry out the rubber seals from the inside of the cylinders - two in each cylinder. Do not damage or mark the insides of the cylinders while doing so. The upper seal in this cylinder has obviously failed.
25. Using a dull pick, gently scrape the corrosion and residue inside the channels of the cylinder that hold the seals. Be very careful not to mark or gouge the cylinder walls. Rinse out with brake cleaner, ensuring no residue remains inside the cylinder.
26. Remove the bleeder bolt from the caliper, clean it, and clean its channel liberally with brake cleaner. Do the same with the brake line channel.
27. Clean all surfaces of the caliper with brake cleaner. If the insides of the cylinders are corroded or have residue, sand very gently with 600 grit, then 1500 grit sandpaper, ensuring you do so in a circular motion. Always ensure any debris is flushed out of the cylinders with brake cleaner.
28. Lubricate the new seals with clean brake fluid to facilitate their insertion. The thicker seal goes in the lower channel, the thinner one goes in the upper channel.
29. Ensure the upper seal does not twist, and that the thin ridges face inward.
30. Lubricate the outside of the pistons with clean brake fluid. Insert the pistons into the cylinder and gently push them all the way in. I find it helpful to have a large pipe, cover the end with a shop towel, and insert it into the piston. This makes it easy to make sure the piston is going in straight, and gives you a handhold to push the piston into the caliper.
31. Note that the rear caliper pistons do not insert all the way like the pistons of the front calipers.
32. Lubricate the inside of the slider pin channel with high temperature brake lubricant.
33. Lubricate one of the new slider boots with clean brake fluid and put it on the slider pin backwards as shown. Push the inner ridge of the boot slightly past the channel on the slider pin. Lubricate the inside of the boot and the outside of the slider pin with high temperature brake lubricant.
34. Lubricate the other slider boot with clean brake fluid and insert it into the caliper. Insert the boot with the slider pin into the other side of the caliper.
35. Push the slider pin through the caliper and out through the first boot, ensuring the first boot is not pushed out of its channel.
36. Ensure the outer lips of the boots are fastened in place properly on the slider pin. Once installed, the slider pin should slide back and forth easily, while the boots seal it.
37. Insert the retainer spring into the caliper.
38. Push the brake pad retaining pins partially into the caliper.
39. Push the brake pads down into the caliper, compressing the spring, and slide them onto the retaining pins. Be careful not to get grease, brake fluid or lubricant on the face of the brake pads. Push the retaining pins all the way through.
40. Place the brake pin retaining bracket in place, and fasten the bracket retaining bolt.
41. Place the new cap over the bleeder threads, then screw the bleeder finger-tight into the caliper.
42. Replace the rotor cover. Ensure the far side is lined up correctly.
43. Pull the old slider pin boot off the caliper frame on the bike.
44. Fill the new one with high temperature brake lubricant.
45. Insert the new boot onto the frame.
46. Lubricate the slider pin with copious amounts of high temperature brake lubricant.
47. Place the caliper over the rotor, line up the bolt holes, insert the pivot bolt, and torque it to 13 ft-lb for 1980-1981, and 17 ft-lb for 1982-1983 models.. You may need to push the slider pin (underneath the "HONDA" on the caliper) out a bit with your fingers in order to get the caliper to line up correctly with the holes.
48. Insert the caliper bolt and torque it to 22 ft-lb.
49. Attach the brake line banjo fitting with two new crush washers. Start the bolt by hand to ensure it is not cross-threaded.
50. Tighten the brake line fitting to 22 ft-lb.
51. Bleed the brakes. I highly recommend using a Mity-vac to bleed the brakes.
52. Replace the saddle bag.
But everytime I get close there is always one more thing that goes wrong.
I have a possible problem with my rear caliper. Specifically, upon assembly with brand new pads, the inboard pad (non-piston side) appears to be leaning inward a few millimeters (smaller gap at the tips than the gap at the pins). I tried turning the spring around and swapping pads between sides. I can't find a combination that will get the inboard pad to stand up straight. I'm concerned that this lean will cause unwanted contact when the brake is at rest.
