Disc Brake Challenge Part II

With the parts checked out, it's time to start tearing down the brakes. Refer to your vehicle's shop manual for the proper wrench sizes for your vehicle. 

Step 1: Removing the caliper retaining bolts

Samuel started by removing the two bolts attaching the brake caliper to the sliding pins on the caliper bracket. These were pretty tight and required some coaxing.

removing caliper bolts

If the bolts are stubborn, spray some penetrating oil on them and let them sit a few minutes. Once you have the bolts loose, make sure you hold onto the brake caliper so it does not drop off. 

Step 2: Removal of the Caliper

Typically the caliper will stick to the caliper bracket assembly.  It may take some coaxing with a screwdriver to pry it away. Again, keep one hand on the caliper so it does not fall!

Never allow the caliper to hang loose on the brake line or hose! It can kink or damage the hose!

prying off caliper

It will swing away from the bracket and brake pads.

Note how much thinner the inboard pad is.  These were past due for replacement.

Step 3: Support the caliper

Once it's loose, you want to support the caliper on a piece of stiff wire or rope. I have an old spring that works great. Samuel just hooked one end in the caliper bolt holes and hooked the other end onto the strut housing. You want to keep the brake line loose so there is no weight on it.
caliper support

Step 4: Removal, Inspection, and Lubrication of the Bracket/Sliding Pins

For this step, Samuel broke loose the two bolts securing the caliper bracket to the hub assembly.  There is one on the bottom shown here and another one at the top. With those bolts removed, the whole bracket comes off.
bracket removal

Note the small rubber boot highlighted by the arrow. This is one of two sliding pins that allow the brake caliper to 'float' freely back and forth to equalize the pressure applied through the brake pads to the brake rotor surfaces. That's why this caliper type is called a Floating Caliper.

He gently popped the rubber boots off and removed the pins from the bracket. He then carefully inspected and cleaned the pins and sockets with brake cleaner spray. The pins should not bind up and they should slide in and out of the socket freely. 

He then dried them off and applied some high-temperature brake grease to the pins and re-installed them. This procedure will vary depending on the vehicle and caliper type. Refer to your specific shop manual.

One of our pins had a torn boot on it which allowed dirt and grime to get to the pin and into the grease.  This caused the caliper to bind up and it was applying more pressure to the inner pad.  We had a caliper pin repair kit handy and I walked Samuel through the replacement of the pin and the boot.  Look how thin the inner pad was!

inner pad

Stay tuned for Disc Brake Challenge Part III:  removal and replacement of the rotors!

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