Replacing your brake pads (Part 3)

(12/8/2013) The brake grease I ordered arrived last week along with a new set of EBC Brakes FA400 organic pads for the rear wheel. My friend Mike Russo invited me over for dinner on Friday, so I got there a little early and pulled my new front pads so I could apply the grease. I also made a close inspection of my rear brake pads and determined that they don't need replacement until next spring.

In this blog post I want to show you what the new pads look like, especially with the brake grease applied to the back sides.

I also took advantage of this opportunity to photograph caliper pistons and inspect my rear pads. I also removed my front axle and greased it--though not with the brake grease. 

New pads - wear groove

The new brake pads come with a wear groove approximately 1/8-inch (3.2mm) thick, as shown in the photo at left. The total pad thickness is approximately 4mm, perhaps a bit more. Thus, when you've worn the pads past the bottom of that groove, you've got 0.8 mm of material left. They should be changed at 1.0 mm. Therefore, when you've worn the pads to the bottom of the groove, you're actually past the point where they should be changed.

Brake caliper pistons

In the videos and the maintenance manual, there is no discussion of removing the front wheel to change brake pads. Unfortunately, I have to remove my front wheel because the calipers will not clear the fender. I'm not sure how others manage it.

With the calipers unbolted--and supported by something such as the small plastic garbage can I used, shown in the accompanying photo--you can see the four large pistons on the inner walls of the caliper.

Many years ago, I had a Honda CM450C and contaminants managed to work their way into the sides of one of the pistons; this caused my front brake to lock up. That's a situation in which you (1) first almost wipe out because as you think you are releasing your brake you twist the throttle and consequently come close to taking a dive, and (2) then cannot even roll the stalled bike. I was sitting there in the middle of the street, stuck. My friend Steve and I had to pry the pistons apart with a screw driver on the spot, on a cold Buffalo afternoon in March. You can thus imagine why I am keen on lubricating and cleaning my brake calipers.

These calipers actually looked pretty clean, so all I did was give them a wipe with a rag. There was a little superficial rust on the inside of one piston. If I had the patience, I could have rubbed it off with some emery cloth. But, seeing as how this would unlikely cause any problems as is, I left it alone. (I'm learning that if something ain't broke, it's usually a bad idea to fix it.)

In the photo at left, you can see the recently installed EBC Brakes organic pads, slightly worn now. In the background, are the two pad pins. Recall that these require a ¼-inch 12-point socket (or box wrench) to remove and install. (You should also have an inch-pound torque wrench to tighten them properly.* Also recall that the caliper bolts require a 10mm 12-point socket or box wrench, and a foot-pounds torque wrench for proper tightening.)

I took this second photo so you can see the two pistons on the outboard side of the caliper.

Brake grease

In order to reduce noise, minimize moisture in the pistons, and prevent rust on the backsides of the pads, I took the advice of one of the mechanics in a YouTube video and applied some specialty brake grease to the back sides of the pads.

For the grease, I purchased Permatex "Ceramic Extreme Brake Parts Lubricant." I don't know how good it is because it's my first time using it. However, based on the reviews I found online, I expect good results.

Permatex uses a bright purple dye (see photo at left) in the grease so you can easily see where it's been applied. I imagine this is a safety feature, as you want to be sure not to get any grease on the braking surface of the pads.

There is a brush attached to the cap, which you use to apply the grease. It's very easy to use. However, as with any dirty job, you will want to wear shop clothes and keep rags handy.

The grease offers the convenience of adhesion as well as lubrication, so when you insert the pad back into the caliper, the grease will actually hold it in place while you work the other pad.

(Note the use of blue painters tape to protect the fender from the caliper. I saw this useful technique on a YouTube video.)  

Rear brake pads

After I finished installing the newly-greased pads and mounted both calipers, I applied conventional lubricant to the front axle, to reduce friction and create a moisture barrier.

I then moved to the back of the bike, right side, to inspect the rear brake pads. I had in hand a new set of pads and was ready to install them. Back around 2004, I failed to pay attention to my rear brake pads and wore them down to the backing plate and warped my rotor. It was a very expensive experience and I hung the bowl-shaped rotor on my garage wall as a reminder to check the rear brakes at least a couple of times a year. (I use my rear brakes almost every time I use my front brakes, unlike some riders who have the bad habit of using only their front brakes.)

After a close visual inspection, I determined that I could put another 3,000+ miles on the rear pads. As there is no expiration date on the new ones I just purchased, I will wait until spring and check my rear brakes again.

I hope you found this series on brakes helpful.

Pray for a short, mild winter, and as always…Keep the shiny side up!

-The Longer Ride

*I plan to write about torque wrenches in a future blog post.