Uneven wear of brake pads, where one side wears more than the other, can be caused by several factors. Here are some common reasons:

1. Caliper Issues: The most common cause of uneven brake pad wear is a problem with the caliper. If the caliper on one side is sticking or not releasing properly, it can cause the brake pad on that side to wear faster. This could be due to a damaged or seized caliper piston, guide pins, or bushings.
2. Brake Hose Restriction: A restricted or damaged brake hose can prevent the caliper from releasing properly. If the hose on one side is deteriorated or blocked, it can cause uneven wear.
3. Uneven Rotor Thickness: If the rotor on one side is significantly thicker or thinner than the other, it can lead to uneven pad wear. This could be due to a manufacturing defect or improper rotor installation.
4. Wheel Cylinder Issues (Drum Brakes): If your vehicle has drum brakes on the rear, uneven wear could be due to a problem with the wheel cylinder. Similar to calipers, if the wheel cylinder on one side is malfunctioning, it can cause the brake shoes to wear unevenly.
5. Suspension or Alignment Problems: Issues with the suspension or alignment of your vehicle can also affect brake wear. If your car has alignment problems or suspension issues, it can lead to uneven braking forces and wear.
6. Driving Habits: Your driving habits can contribute to uneven brake pad wear. If you frequently use your brakes more on one side (e.g., taking tight turns in one direction), it can result in uneven wear.
7. Low-Quality Brake Parts: Sometimes, low-quality or aftermarket brake components may not wear evenly or perform as well as OEM parts.

To diagnose the specific cause of uneven brake pad wear, it’s best to have your vehicle inspected by a qualified mechanic. They can perform a thorough inspection, identify the issue, and recommend the necessary repairs or replacements. Ignoring uneven brake pad wear can lead to reduced braking performance, safety issues, and more costly repairs down the line.

If your rear brake pads are wearing more quickly than your front brake pads, there could be several reasons for this imbalance in brake wear. Here are some possible explanations:

1. Vehicle Weight Distribution: Some vehicles have a rear-weight bias, meaning they carry more weight in the rear. This extra weight can place greater demands on the rear brakes, causing them to wear more quickly than the front brakes. This is common in vehicles like trucks or SUVs where the engine is located in the front.
2. Brake Bias: The brake bias of your vehicle may be set up in a way that directs more braking force to the rear wheels. This can be designed for stability and control during braking. However, it can also result in faster rear brake pad wear.
3. Driving Habits: Your driving habits can have a significant impact on brake wear. If you tend to brake hard or use the brakes frequently, especially while going downhill, this can wear out the rear brake pads faster. Additionally, using the brakes more in stop-and-go traffic or city driving can contribute to rear brake wear.
4. Emergency Brake Usage: If you use your emergency brake (parking brake) frequently, it can wear out the rear brake pads faster since the parking brake is typically connected to the rear brakes.
5. Brake Pad Material: The type of brake pad material used on the rear brakes can also affect wear rates. Some brake pad materials may wear faster than others.
6. Caliper or Brake Hardware Issues: Problems with the rear brake calipers, such as sticking caliper pistons or malfunctioning caliper slides, can cause uneven brake pad wear. If the calipers do not release properly after braking, the rear brake pads can remain in contact with the rotor, leading to accelerated wear.
7. Rotor Condition: If the rear brake rotors are scored, worn, or damaged, it can cause increased wear on the brake pads.
8. Improper Brake Maintenance: Inadequate maintenance, such as infrequent brake pad inspections, lubrication of caliper slides, or brake fluid changes, can lead to uneven wear on the rear brake pads.

To address this issue, it’s a good idea to have your vehicle inspected by a qualified mechanic. They can assess the condition of your brakes, identify the specific cause of the uneven wear, and recommend the necessary repairs or adjustments to ensure balanced brake performance. Regular brake maintenance and servicing can help extend the life of your brake components and improve overall safety.