Rebuilding the brake calipers - Honda CX500
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We're rebuilding a set of Honda CX500 brake calipers today - up for renewal is one set of sad and neglected brake calipers.
This pair are from a 1980 Honda CX500 from Australia with dual front discs, so there's two to deal with. We'll start by utilising a CX500's forks (you already have a working one laying around, right?) so we can easily undo the slide pin bolts - which are the rusty two visible here:
Remove the matching caliper from the bike and temporarily install the soon-to-be-rebuild caliper. Alternately, you could hold the caliper in a vise if you have one handy. Attached to the bike:
Loosen the two slide pin bolts with a 12mm socket - lower:
...and upper:
Now we take the caliper back off the bike and undo the bolts all the way:
Other than a rusty head, they don't look too bad:
Now that these are removed we can separate the two halves of the caliper - here you can see them slightly lifted away:
...then:
This leaves us with the caliper bracket:
...and the half with the piston:
Taking a closer look at the half with the piston, we have the bleed valve on the left and the hole that the brake line banjo usually screws into on the right (shot from before caliper separation):
The piston has seen better days:
Looking from the side into the piston:
Now we can take a look at the caliper bracket:
Viewed from the top, we can see the gap between the brake pads where the disc usually sits. The brake shim has fallen off to the left.
These shims stop brake noise and vibration, and are worth having. You can make your own out of thin metal if you don't have them. On this side we have the slide pins:
...and in the middle the brake pads:
Push up with the thumb:
...and then lift away:
The other side should be as easy to remove:
...just lift:
One pair of brake pads. Since these are of unknown age and have been exposed to who knows how many contaminants they will be going straight into the bin. Be careful handling these as if they are really old they may contain asbestos - though whether they contain asbestos or not, don't inhale brake dust as it's just plain not good for you.
On either side of the pads should be a metal shim:
...and on the other side:
These should lift away easily.
Now we turn our attention to the slide pins:
They should lift out easily. If they are stuck you may need to twist and pull for a while:
These ones slid out readily:
The slide pins on the lower side also came out easily:
Half out:
The rubber sleeve is in good condition, which is lucky as they seem to be unobtainable OEM. We're trying out some different techniques to replace them, and will update when we know what works.
Look into the slide pin bores to see how much cleaning they will need - a bit of dried gunk in this one:
Continued in Part 02... yet to be written!
