This article is one in a series that have been released in conjunction with Wayne's new book, 101 Performance Projects for Your Porsche Boxster. The book contains 312 pages of full color projects detailing everything from performance mods to changing your brake pads. With more than 950+ full-color glossy photos accompanying extensive step-by-step procedures, this book is required reading in any Boxster owner's collection. The book is currently available and in stock now. See The Official Book Website for more details.
Check out some other sample projects from the book:
Replacing your brake pads is one of the easiest jobs to perform on your Boxster. In general, you should inspect your brake pads about every 10,000 miles, and replace them if the material lining of the pad is worn down enough to trigger the pad replacement sensor. In reality, most people don't inspect their pads very often, and usually wait until they see the little brake-warning lamp appear on the dashboard. It's a wise idea to replace the pads, and inspect your discs as soon as you see that warning lamp go on.
If you ignore the warning lamp, you may indeed get to the point of metal on metal contact, where the metal backing of the pads may be contacting the brake discs. Using the brakes during this condition will not only give you inadequate braking, but will also begin to wear grooves in your brake discs. Once the discs are grooved, they are damaged, and there is often no way to repair them. Resurfacing will sometimes work, but often the groove that is cut will be deeper than is allowed by the Porsche specifications. The smart thing to do is to replace your pads right away.
Brake pads should only be replaced in pairs: replace both front pads or both rear pads at a time. The same rule applies to the brake discs that should be checked each time you replace your brake pads.
The procedure for replacing pads on all the wheels is basically the same. There are slight configuration differences between front and rear brakes, but in general the procedure for replacement is similar. The first step is to jack up the car and remove the road wheel (slightly loosen the lug nuts before you lift the car off of the ground). This will expose the brake caliper that presses the pads against the disc. Make sure that the parking brake is off when you start to work on the pads.
Begin by using a pair of needle-nose pliers to remove the brake pad sensor (see Figure 1). The pads are held within the caliper by two retaining pins. There are also small retaining clips that hold these two retaining pins in the caliper. Start by removing the small retaining clips, and then tap out the retaining pins using a small screwdriver and a hammer (see Figure 2). When the two retaining pins are removed, the cross spring which holds the pads in place will fall out. Now, the pads can be pried out with a screwdriver (Figure 3). Use the small holes on the pads that normally surround the retaining pin as a leverage point for removing them. They may require some wiggling to remove, as it is sometimes a tight fit. It is important to keep in mind that the caliper piston is also probably pressing against the pads slightly, and will add to the difficulty in removing them.
Once you have the pads removed, inspect the inside of the caliper. You should clean this area with some compressed air and isopropyl alcohol. Make sure that the dust boots and the clamping rings inside the caliper are not ripped or damaged. If they are, then the caliper may need to be rebuilt (see Pelican Technical Article: Rebuilding Brake Calipers).
At this point, you should inspect the brake discs carefully. Using a micrometer, take a measurement of the disc thickness. If the disc is worn beyond its specifications, then it's time to replace it along with the one on the other side. See Project 55 for more information.
The installation of the new brake pads is quite easy. You will need to take a small piece of wood or plastic and push the caliper piston back into the caliper. This is because the new pads are going to be quite a bit thicker than the old ones, and the piston is set in the old pad's position. Pry back the piston using the wood, being careful not to use too much force (see Figure 4). Using a screwdriver here is not recommended as it can accidentally damage the dust boots and seals inside the caliper. Make sure that you push both pistons (inside and outside) back in the caliper.
Be aware that as you push back the pistons in the calipers, you will cause the level of the brake reservoir to rise. Make sure that you don't have too much fluid in your reservoir. If the level is high, you may have to siphon out a bit from the reservoir to prevent it from overflowing. Also make sure that you have the cap securely fastened to the top of reservoir. Failure to do this may result in brake fluid accidentally getting on your paint.
When the piston is pushed all the way back, you should then be able to insert the pad into the caliper. If you encounter resistance, double check to make sure that the inside of the caliper is clean. You can use a small hammer to tap it in, but don't use too much force. When the pads are in place, insert the retaining pins and spring clip back into place. It's wise to use a new set of pins and clips when replacing your pads. Make sure that you replace the pin retaining clips inside the small holes in the retaining pins.
In general, I recommend removing and replacing the brake pads one side at a time. When the piston is pushed back into the caliper, it will try to push out the piston on the opposite side of the caliper. Leaving the brake pad installed on one side keeps the piston from being pushed out too far.
You also may want to spray the back of the brake pads with some anti-squeal glue. This glue basically keeps the pads and the pistons glued together, and prevents noisy vibration. Some brands of pads may come with anti-squeal pads already attached to the rear surface. Anti-squeal pads can also be purchased separately as sheets that are peeled off and stuck on the rear of the pads.
When finished with both sides, press on the brake pedal repeatedly to make sure that the pads and the pistons seat properly. Also make sure that you top off the master cylinder brake fluid reservoir if necessary. Brake pads typically take between 100 and 200 miles to completely break in. It's typical for braking performance to suffer slightly as the pads begin their wear-in period. Make sure that you avoid any heavy braking during this period.
Figure 1
Grab the brake pad sensor (yellow and green arrow) with a pair of needle-nose pliers. If your brake sensors activated the lamp on your dashboard, they should be replaced with new ones. Disconnect the sensor, and plug in the new one: the plug for the sensor is located in the top of the wheel well (orange arrow). This photo also shows the wheel speed sensor and plug (red arrow and purple arrow), which is used with the anti-lock braking system (ABS)
To remove the old pads, pull out the small pin retainers (blue arrow, inset), and tap out the retaining pins (green arrow) with a screwdriver and a small hammer. They should slide out pretty easily, as there is usually no load on them. If there is much difficulty encountered during the removal process, then tap on the pads slightly to remove pressure from the pins. The yellow points to the electrical cable clip for the brake pad sensor.
Pulling out the pads usually involves the use of a screwdriver for leverage. The pads are loose in the caliper, but it's a pretty tight fit, and there is usually lots of dust and debris in the caliper. Wiggle the pads back and forth in order to pry them free. Although these parts usually can be reused, some people prefer to install new retainer kits. The kits include two new retainer springs, four pin clips and four pins that are used to hold the pads into the caliper.
When you are ready to install the pads back into the caliper, use a wooden or plastic handle to push back the caliper pistons. Don't use a screwdriver, as you might damage some of the piston seals. Keep your eye on the fluid level in the master cylinder reservoir: it can overflow when you push back on the pistons.
Don't forget to reinstall the small retaining clips for the pad retaining pins. The completed assembly should be carefully tested before you do any performance driving. Brake pads can also take several hundred miles to full break themselves in. Exercise care when driving with brand new brake pads.
Comments: Hey there.. I am going to change my oil and brake pads on 08 Boxster hopefully this sunday... But my question that I have is.. I see the other 2 pins and clips shown in your photos... But I really did not see a photo as to wherer they should go during the procedure... Please help..
January 12, 2012
Check out some other sample projects from the book:
