How to Remove a Parking Brake Caliper

Replacing your brake pads is a fundamental maintenance task for any car owner, and for those fortunate enough to own a Porsche 911, it's a job that can often be tackled at home with the right guidance. While the process for replacing pads on all wheels is largely similar, there are slight configuration differences between the front and rear brakes. This guide focuses on the essential steps involved in removing the parking brake caliper, a crucial part of the braking system that ensures your vehicle remains stationary when parked.

Understanding the Parking Brake System

The parking brake, often referred to as the handbrake or e-brake, is a vital safety feature. In many modern vehicles, including the Porsche 911, it's integrated into the rear braking system. This means the same calipers that provide stopping power during normal driving also apply a mechanical force to hold the car in place. When it comes time to replace your brake pads, you'll be interacting directly with these calipers.

When to Replace Brake Pads and Discs

It's generally recommended to inspect your brake pads approximately every 10,000 miles. The most common indicator for replacement is when the pad material is worn down to the point where it triggers the replacement sensor, illuminating a warning lamp on your dashboard. However, many drivers tend to defer this maintenance until that warning light appears. It's a wise practice to replace the pads and inspect the brake discs as soon as you see that warning lamp. Ignoring it can lead to metal-on-metal contact between the brake pad's metal backing and the brake disc. This not only compromises your braking performance but also starts to wear grooves into the discs. Once grooved, brake discs are often beyond repair, or at least beyond the manufacturer's specifications for resurfacing. Therefore, proactive replacement is key.

Essential Tools and Parts

Before you begin, ensure you have the necessary tools and parts. This project typically takes around 2 hours and has an estimated parts cost of $150. You will need:

Tools Required:

• Screwdriver
• Isopropyl alcohol
• Wooden block (or a dedicated brake caliper retracting tool)
• Needle-nose pliers
• Hammer

Parts Required:

• New brake pads
• Brake pad sensors
• Vibration dampeners (if equipped, these are single-use and should be replaced)
• Hardware kit (including new retaining pins and clips)

Step-by-Step Caliper Removal and Pad Replacement

1. Preparation: Safety First

Begin by ensuring the parking brake is disengaged. You'll need to lift the car and remove the road wheel you'll be working on. It's advisable to slightly loosen the lug nuts before lifting the car off the ground. Once the wheel is off, you'll have clear access to the brake caliper.

2. Removing the Brake Pad Sensor

Locate the brake pad sensor. Using a pair of needle-nose pliers, carefully remove the sensor. These sensors are typically clipped into the brake pad and provide an early warning of wear.

3. Releasing the Retaining Pins

The brake pads are held in place within the caliper by two retaining pins. Small retaining clips secure these pins. First, remove these small retaining clips. Then, using a small screwdriver and a hammer, gently tap out the retaining pins. Be firm but avoid excessive force that could damage the caliper.

4. Removing the Cross Spring

Once the two retaining pins are out, a cross spring that holds the pads in position will likely become loose or fall out. This spring helps to keep the pads stable and prevent rattle.

5. Prying Out the Old Brake Pads

With the pins and spring removed, the old brake pads can now be carefully pried out. The pads usually have small holes that were around the retaining pins, which can serve as leverage points. You may need to wiggle them a bit, as they can sometimes be a tight fit. Keep in mind that the caliper piston may still be pressing slightly against the pads, adding to the resistance.

6. Inspecting and Cleaning the Caliper

With the pads removed, take this opportunity to inspect the inside of the caliper. Clean the area using compressed air and isopropyl alcohol. Carefully check the dust boots and clamping rings within the caliper for any signs of tearing or damage. If these are compromised, the caliper itself may require rebuilding. For detailed instructions on caliper rebuilding, refer to the Pelican Technical Article: Rebuilding Your Brake Calipers on your Porsche 911 Carrera.

7. Inspecting the Brake Discs

This is also the ideal time to thoroughly inspect your brake discs. Use a micrometer to measure the disc thickness. If the disc is worn beyond its specified limits, it's time to replace it, along with the disc on the opposite side of the car. Consult your vehicle's service manual for specific thickness specifications.

8. Retracting the Caliper Piston

The new brake pads are thicker than the old ones, so you'll need to retract the caliper piston back into the caliper. Use a piece of wood, plastic, or a dedicated brake caliper retracting tool to push the piston back. Apply steady pressure, being careful not to use excessive force that could damage the dust boots and seals inside the caliper. If you're working on a multi-piston caliper, ensure you retract all pistons. As you push the pistons back, the level of brake fluid in the reservoir will rise. Check the brake fluid reservoir and siphon out a small amount if necessary to prevent overflow. Ensure the reservoir cap is securely fastened to prevent brake fluid from coming into contact with your paintwork.

9. Installing New Brake Pads

Once the piston is fully retracted, you should be able to insert the new brake pads into the caliper. If you encounter resistance, re-clean the inside of the caliper. You can gently tap the pads into place with a small hammer, but again, avoid excessive force.

10. Reinstalling Retaining Pins and Clips

When the new pads are seated correctly, reinsert the retaining pins and the cross spring. It's highly recommended to use a new set of retaining pins and clips, as these small components are inexpensive and critical for safety. Ensure the small retaining clips are properly secured in the holes of the retaining pins.

11. One Side at a Time Strategy

A smart approach is to replace the brake pads on one side of the car at a time. When you retract the piston on one caliper, it can push the piston on the opposite side further out. Leaving the brake pad installed on the opposing side helps to prevent the piston from being pushed out too far, making the process smoother.

12. Replacing Vibration Dampeners

It's also a good idea to replace the vibration dampeners, if your vehicle is equipped with them. These small components help to keep the pads and pistons snug and prevent brake noise and vibration.

13. Final Checks and Bedding-In

After completing the replacement on both sides, repeatedly press the brake pedal. This action will seat the new pads against the pistons and discs. Check and top off the master cylinder brake fluid reservoir if necessary. New brake pads typically require a bedding-in period of 100 to 200 miles. During this time, you may notice a slight decrease in braking performance. It's crucial to avoid any heavy braking during this wear-in period to ensure optimal performance and longevity of your new pads.

Complementary Modifications

While you're working on your brakes, consider these complementary modifications:

• Caliper rebuild: If you found any damage during your inspection, consider a caliper rebuild.
• Brake disc replacement: Replace worn discs at the same time as your pads.
• Stainless steel brake lines: Upgrade to stainless steel brake lines for improved pedal feel and responsiveness.

Frequently Asked Questions

Q1: How often should I replace my brake pads?

It's recommended to inspect your brake pads every 10,000 miles. Replace them when the pad wear indicator sensor is triggered or when the pad material is significantly worn.

Q2: Can I use a screwdriver to retract the caliper piston?

While it might seem convenient, using a screwdriver to retract the caliper piston is not recommended. It can easily damage the dust boots and seals within the caliper, leading to potential leaks and premature failure.

Q3: What happens if I don't replace my brake pads when the warning light comes on?

Ignoring the warning light can lead to metal-on-metal contact between the brake pads and discs, causing significant damage to the discs and severely compromising your braking ability. This can be a serious safety hazard.

Q4: Do I need to replace brake discs when replacing pads?

It's not always mandatory, but it's highly recommended to inspect your brake discs for wear and damage whenever you replace your brake pads. If the discs are worn below their minimum thickness or have significant scoring, they should be replaced to ensure optimal braking performance and safety.

Q5: What is the bedding-in period for new brake pads?

New brake pads typically require a bedding-in period of 100 to 200 miles. During this time, avoid aggressive braking to allow the pads and discs to mate properly for maximum performance.

Hot Tip

Check your brake discs when replacing your pads in case they have worn too thin.