Replacing the brakes on your Infiniti QX70 is a crucial maintenance task that ensures your safety and the longevity of your vehicle. While it might seem daunting, with the right tools, knowledge, and a bit of patience, you can confidently perform this repair yourself, saving money on labor costs. This guide provides a comprehensive, step-by-step approach to replacing the brake pads and rotors on your Infiniti QX70.
This is a task that requires careful attention to detail and adherence to safety precautions. Always prioritize your safety by wearing appropriate protective gear and working in a well-lit and ventilated area. If you are not comfortable performing this task, seek the assistance of a qualified mechanic.
| Topic | Description | Tools & Materials Needed |
|---|---|---|
| Brake System Components | Understanding the key components like brake pads, rotors, calipers, brake lines, and master cylinder is essential for effective brake maintenance and repair. Each component plays a vital role in the braking process. | N/A (Understanding is the key) |
| Signs of Brake Wear | Knowing the signs that your brakes need replacement, such as squealing noises, grinding sounds, longer stopping distances, or a pulsating brake pedal, is crucial for timely maintenance. Ignoring these signs can lead to dangerous situations. | N/A (Observation is the key) |
| Tools and Materials | A comprehensive list of the tools and materials required for the brake replacement job, including specific socket sizes, torque wrenches, brake cleaner, and the correct replacement brake pads and rotors for your Infiniti QX70. | Jack, Jack stands, Wheel chock, Lug wrench, Socket set, Torque wrench, Brake cleaner, Brake grease, C-clamp or brake caliper compression tool, New brake pads, New brake rotors (optional), Brake fluid (DOT 3 or DOT 4), Gloves, Safety glasses, Wire brush, Penetrating oil (optional), Rubber mallet (optional) |
| Preparation | Steps to prepare your vehicle for the brake replacement, including parking on a level surface, engaging the parking brake, and safely lifting the vehicle using a jack and jack stands. Emphasizing safety is paramount. | N/A (Following safety procedures) |
| Removing the Wheel | Detailed instructions on how to safely remove the wheel, including loosening the lug nuts before lifting the vehicle and properly storing the wheel after removal. | Lug wrench |
| Removing the Caliper | A step-by-step guide on how to safely remove the brake caliper, including disconnecting the brake line (if necessary) and properly supporting the caliper to prevent damage to the brake line. | Socket set, Wrench (for brake line fitting if disconnecting), Brake line clamp (if disconnecting), Wire or bungee cord |
| Removing the Brake Pads | Instructions on removing the old brake pads from the caliper and inspecting the caliper for any signs of damage or wear. | Screwdriver (for prying if needed), Wire brush |
| Removing the Rotor | A detailed explanation of how to remove the brake rotor, including dealing with stubborn rotors that may be rusted in place. | Screwdriver (for removing retaining screws), Rubber mallet, Penetrating oil (optional) |
| Cleaning and Inspection | The importance of cleaning the hub surface and inspecting the wheel bearings for any signs of wear or damage before installing the new rotor. | Wire brush, Brake cleaner |
| Installing the Rotor | How to properly install the new brake rotor, ensuring it is seated correctly and secured with any retaining screws. | Screwdriver (for installing retaining screws) |
| Installing the Brake Pads | Step-by-step instructions on installing the new brake pads into the caliper, including applying brake grease to the appropriate contact points. | Brake grease |
| Reinstalling the Caliper | How to reinstall the brake caliper, including compressing the caliper piston and ensuring the caliper is properly aligned and secured. | C-clamp or brake caliper compression tool, Socket set, Torque wrench |
| Reconnecting Brake Line | If the brake line was disconnected, instructions on how to reconnect it properly and bleed the brakes. | Wrench (for brake line fitting), Brake bleeder kit or assistance from another person, Brake fluid (DOT 3 or DOT 4) |
| Reinstalling the Wheel | Instructions on reinstalling the wheel, including tightening the lug nuts in a star pattern and lowering the vehicle. | Lug wrench, Torque wrench |
| Final Checks and Bedding | Final checks to ensure everything is properly installed and a procedure for bedding in the new brake pads and rotors. | N/A (Driving carefully and performing bedding procedure) |
Detailed Explanations
Brake System Components: The braking system is composed of several vital parts that work together to bring your vehicle to a safe stop. The brake pads are friction materials that press against the rotors. Rotors are metal discs that rotate with the wheels. Calipers house the brake pads and use hydraulic pressure to squeeze the pads against the rotor. Brake lines transmit the hydraulic pressure from the master cylinder to the calipers. The master cylinder is a reservoir containing brake fluid that, when the brake pedal is pressed, generates the hydraulic pressure needed to actuate the brakes.
Signs of Brake Wear: Recognizing the warning signs of worn brakes is crucial for safety. Squealing noises when braking often indicate worn brake pads. Grinding sounds suggest that the brake pads have worn down completely, and the metal backing is rubbing against the rotor. Longer stopping distances indicate that the brakes are not functioning efficiently. A pulsating brake pedal can be a sign of warped rotors. If you experience any of these symptoms, it's time to inspect your brakes.
Tools and Materials: Gathering the necessary tools and materials before starting the brake replacement is essential. You'll need a jack and jack stands to safely lift and support the vehicle. A wheel chock will prevent the vehicle from rolling. A lug wrench is required to remove the wheel. A socket set and torque wrench are needed for various bolts and nuts. Brake cleaner will help clean the brake components. Brake grease should be applied to specific contact points to prevent noise. A C-clamp or brake caliper compression tool will compress the caliper piston. New brake pads and rotors (if needed) are, of course, essential. Brake fluid (DOT 3 or DOT 4) is needed if you plan to bleed the brakes. Gloves and safety glasses will protect you during the process. A wire brush will help clean rust and debris. Penetrating oil (optional) can help loosen stubborn bolts. A rubber mallet (optional) can help remove a stuck rotor.
Preparation: Before starting any work on your vehicle, ensure it is parked on a level surface. Engage the parking brake firmly. Place wheel chocks behind the rear wheels (if working on the front brakes) or in front of the front wheels (if working on the rear brakes). Loosen the lug nuts on the wheel you'll be removing before lifting the vehicle. Use the jack to lift the vehicle at the designated jacking points. Once the vehicle is lifted, securely place jack stands under the frame rails near the jacking points. Never work under a vehicle supported only by a jack.
Removing the Wheel: After the vehicle is safely supported on jack stands, completely remove the lug nuts and carefully remove the wheel. Store the wheel safely out of the way.
Removing the Caliper: Locate the bolts that hold the brake caliper in place. These are usually located on the back of the caliper. Use a socket to remove these bolts. If the brake line needs to be disconnected, use a wrench to loosen the brake line fitting. Be prepared for brake fluid to leak out. Use a brake line clamp to minimize fluid loss. Once the caliper is free, carefully remove it and support it with a wire or bungee cord so it doesn't hang by the brake line. Hanging the caliper by the brake line can damage the line.
Removing the Brake Pads: With the caliper removed, the brake pads should easily slide out. Note the orientation of the pads before removing them. Use a screwdriver or pry bar if necessary to gently remove the pads. Inspect the caliper for any signs of damage, such as leaks or torn dust boots.
Removing the Rotor: The brake rotor may be held in place by retaining screws. If present, remove these screws. If the rotor is stuck due to rust, use a rubber mallet to gently tap around the rotor to loosen it. You can also apply penetrating oil to the hub surface and let it sit for a while before attempting to remove the rotor. Be careful not to damage the wheel studs while tapping the rotor.
Cleaning and Inspection: Before installing the new rotor, thoroughly clean the hub surface with a wire brush to remove any rust or debris. This ensures proper rotor seating and prevents vibrations. Inspect the wheel bearings for any signs of play or roughness. If the wheel bearings are worn, they should be replaced.
Installing the Rotor: Place the new rotor onto the hub, aligning the holes for the retaining screws if present. Install the retaining screws and tighten them securely. Ensure the rotor is seated flush against the hub.
Installing the Brake Pads: Apply a thin layer of brake grease to the back of the new brake pads and to the contact points on the caliper where the pads will slide. This helps prevent squealing noises. Slide the new brake pads into the caliper, ensuring they are properly seated.
Reinstalling the Caliper: Use a C-clamp or brake caliper compression tool to compress the caliper piston back into the caliper body. This is necessary to create enough space for the new, thicker brake pads. Carefully slide the caliper over the new brake pads and rotor. Align the caliper with the mounting bracket and reinstall the caliper bolts. Tighten the bolts to the manufacturer's specified torque using a torque wrench.
Reconnecting Brake Line: If you disconnected the brake line, carefully reconnect it to the caliper. Tighten the fitting securely, but be careful not to overtighten it. Bleed the brakes to remove any air from the brake lines. This can be done using a brake bleeder kit or by having someone pump the brake pedal while you open and close the bleeder valve on the caliper. Add brake fluid to the master cylinder as needed to prevent it from running dry.
Reinstalling the Wheel: Carefully reinstall the wheel, aligning the lug holes with the wheel studs. Hand-tighten the lug nuts in a star pattern. Lower the vehicle until the wheel is just touching the ground. Tighten the lug nuts to the manufacturer's specified torque using a torque wrench, again in a star pattern. Fully lower the vehicle and remove the jack and jack stands. Give the wheel a final check to ensure it is secure.
Final Checks and Bedding: Before driving, double-check that all bolts and fittings are tightened securely. Pump the brake pedal several times to ensure the brakes are working properly. Perform a brake bedding procedure to transfer brake pad material to the rotor surface. This typically involves a series of moderate to hard stops from a specific speed. Refer to your brake pad manufacturer's instructions for the recommended bedding procedure.
Frequently Asked Questions
How often should I replace my brake pads? Brake pad replacement frequency depends on driving habits, but typically every 25,000 to 70,000 miles is a good guideline. Listen for squealing or grinding noises as indicators.
How do I know if my rotors need replacing? If you feel a pulsation in the brake pedal when braking, or if the rotors are visibly scored or worn, they likely need replacing. Rotors are also typically replaced after every other brake pad replacement.
What type of brake fluid does my Infiniti QX70 use? Your Infiniti QX70 typically uses DOT 3 or DOT 4 brake fluid. Check your owner's manual for the specific recommendation for your vehicle.
Can I use any brand of brake pads and rotors? It's best to use brake pads and rotors that are specifically designed for your Infiniti QX70. Consider quality brands that offer good performance and durability.
What happens if I don't replace my brakes when needed? Ignoring worn brakes can lead to longer stopping distances, damage to the rotors, and potentially dangerous driving situations. It's a crucial safety concern.
Conclusion
Replacing the brakes on your Infiniti QX70 is a manageable task for the experienced DIYer, provided you follow the correct procedures and prioritize safety. Remember to use quality parts and tools and always double-check your work before driving. Regular brake maintenance is essential for your safety and the longevity of your vehicle.