Saturday, November 3, 2007

Saturday Afternoon Brake Change

The last time I rotated my tires, I noticed that the rear brakes on my 2002 Impala were wearing thin. Yesterday, I got some break pads and today (after painting my purgala, running some Christmas lights on my house and garage, and putting away some of the kids toys and the grill for the winter), I decided to it was time to change my breaks.

Changing brakes is a pretty easy job that does require too much time or skill. The hardest part of the change was opening the trunk, unscrewing the spare cover, and taking out the spare to get to the jack and tire iron.

Once I had the jack in hand, I positioned it to safely lift up the rear of the car.

Next, I removed the hubcap and the lugnuts. (I had pre-loosed the lugnuts prior to jacking up the car. This is necessary with a front wheel drive.)

Once the rim was out of the way, I used a 14 mm socket to loosen and remove the two bolts that hold the brake caliper to the brake disc.

Once the bolts are removed, the brake caliper can easily be slide up, off, and out of the way so that you can access the worn brake pads.

The pads were definitely worn, put fortunately, I had noticed they needed changed before they got to the point of squeeking and gouging the brake disc.

There are two brake pads, one on the front of the disc, and one on the backside of the disc. They are held into place by some thin clips. The worn pads can be easily removed to make way for the new brake pads.
Once the new pads are in place. Most new brakes come with a couple of packets of a petroleum based lubricant that you are supposed to use on the backs of the brake pads, the caliper, and the bolts that hold the caliper into place.
Once the lubricant is on the brake pads, I turned my attention to the caliper assembly. There is a cylinder inside the caliper that forces down on the brake pads when the brake pedal is applied by the driver. Brake fluid in the brake lines uses hydralic force to keep this cylinder tight against the back of the brake pad. As the pads are used, they are worn down and the thickness of the pads decrease. Therefore hydralic pressure from the braking system continues to push the cylinder further toward the brake pad to make up the difference in thickness and keep the pad close to the disc.
The problem is that this cylinder must be returned to its original position before you have enough clearance to put the caliper back into place over the brake pads. The first time I changed a set of brakes, I figured out that I could use a simple "C" clap to push the cylinder back into its original position.

Once the cylinder is in its original position, the caliper is ready to be reinstalled. When you put it back into place, make sure that the thin rubber sleeves that will cover the bolts and protect them against the "elements" are properly aligned and not ill-positioned between the caliperand disc.
Use the provided package of lubricate to grease up the two caliper bolts and slip them into position. Using a 14 mm socket, make sure they are securely tightened.
Now that the caliper has been reinstalled, you are ready to put the rim back on the car. Once the rim is on the car you can replace the lugnuts and tighten by hand. The next step is to lower the jack and use the tire iron to tighten all lugnuts.
Once the car is back on the ground. Simply move all of your tools and the jack to the other side of the car and repeat the entire process. Before you know it, you will have a new set of brakes on your car and still have time to take the car out for a Saturday night cruise!