Changing Rear Brake Pads

As long as I have my bike apart for a new wheel, I took the opportunity to check out other stuff. And yeah, the brake pads are two years old. So I changed them with some new ones, and decided to keep a photo howto. This is for my H-D Sportster (2008 XL883L) but maybe it will be beneficial to you too.

First, an overview. On the left-hand side of the rear wheel (removed in a previous blog post) you'll see the brake caliper and brake pads.

Center: The brake pads inside the caliper.

View from the left. Note the brake bleeding cap, and the cap covering the retaining pin.

The pads are held in place by a pin/bolt that runs through them. So, let's remove the pin. First, remove the plastic cap. Then, get an Allen wrench and remove the pin. It was torqued down pretty good, so I had to use my socket wrench extender as a longer handle. Eventually, out comes the bolt and the two pads fall right out.

The Allen bolt was quite tight, so I needed a longer lever.

The plastic cap and the Allen head of the retaining pin.

Now we need to squeeze out some excess brake pressure, to make room for the new brake pads. After all, the new brake pads are much thicker than the old ones. If you try to squeeze the pads in now, there's probably not enough room, and definitely not enough for the brake rotor too.

A new pair of pads would completely fill the space, leaving no room for the brake rotor. So we need to go the extra step of squeezing out some brake fluid.

This technique worked well: The caliper assembly isn't bolted into place, so I could set it on to my toolbox. I used a metal rod (again the extender from my socket set) and simply leaned on the ppiston. I had an assistant (thanks, Laura!) with the 10mm wrench open up the bleeder screw to let fluid out, then tighten without letting in any air.

It's very important that you not let air back in to the brake caliper. When I was about to stop pressing on the piston, I had the assistant tighten the valve shut as fluid was still coming out. Don't stop squeezing, or you'll suck air into the brake system.

Squeezing the caliper with a trusty metal rod. Bottom-center is the bleeder valve. An assistant with a #10 wrench loosens to let brake fluid out, but tightens again before I stop squeezing so as not to suck in air.

Eventually the piston was flush with the caliper body, and left sufficient space for both pads and a good-looking space between them.

As the saying goes, installation is the reverse of removal. Seat the new pads just like the old ones, put the pin back in, tighten down what you loosened.

The new pads and the retaining pin. From here we just tighten things down.

The pads will only go in one way, but it's easy to forget. If you get confused as to the orientation of the pads, look at the old pads; they have clear markings on them which should clue you in.

Which way do the pads go? Check the old one. The circle is from the piston, the two dashes are from the C-shaped side. The holes are of course for the pin, so now it's pretty clear.

The inside pad (the one not against the piston) fits in to a little space at the bottom. You will feel it fit in to its slot, and the whole thing won't fit together unless you do it right.

So there you have it, a photo guide to changing out your rear brake pads. The process for front pads is nearly identical, just a slightly different set of nuts and two extra nuts for the fender.