As you probably know already, your brake pads do not last forever. Brake pads (and brake shoes on a drum brake system) contain sacrificial friction materials designed to wear away with use in order to protect other brake system components.
How quickly those pads wear out depends on a number of circumstances: the size of your vehicle, your driving habits, and environment, whether you tow or haul heavy loads, and so on. The composition of the friction material (whether they are organic, semi-metallic, or ceramic) makes a difference too. Even their location on your vehicle, front or rear, impacts how quickly they wear out. Some drivers may see as much as 60K miles of service out of a pair of pads, while others might realize only 25-30K miles.
Most brake pads, as a rule, should be replaced when they wear down to minimum specifications – not when they are totally depleted. Many states require that the friction material on brake pads be at least 1/16” thick. Most professionals recommend replacing them before they wear that far. On inspection, typically anything less than 1/8” is recommended for replacement. If a pad gets too thin, braking effectiveness diminishes, and the chance of damaging other brake components increases.
What is a “complete” brake job?
Though there is no specific definition of a complete brake job, in general, it means to have all of the relevant components of your brakes inspected and serviced or replaced, as opposed to the minimum (i.e. the pads).
In a disc brake system, every time you step on the brake pedal, the master cylinder pump exerts force on the brake fluid in a system of tubes and hoses to hydraulic clamping devices called calipers. Held inside the calipers and sandwiched around metal discs (brake rotors) attached to your wheels are the brake pads. You press the pedal, the caliper clamps down, and the brake pads are squeezed against the spinning rotors to stop your vehicle.
When your brake pads wear down, not only is it important to replace the pads, but also the hardware – clips, bushings, guides, et al. – that hold the pads in place and allow them to move freely. Sometimes even the brake rotors need to be replaced since they too wear out over time.
Unfortunately, some drivers seek out a cheap brake service. And they get what they pay for: a set of pads. Known as “pad slapping”, the practice of replacing only the brake pads can lead to premature and uneven wear of the new pads. There are times when a vehicle manufacturer might recommend replacing only the pads the first time they wear out (when a vehicle is still relatively new), but other than that, at the very least, the rotors need to be addressed by either resurfacing or replacing them.
And then there is the question of the brake hardware. Your brake pads must be able to “float” alongside the rotor when you are driving. They should not be rubbing against the rotor when you have your foot off of the brake pedal. That means they need to be free to slide toward and away from the rotor. Lubricated caliper guide pins enable the halves of the caliper to move smoothly. Pin boots keep the lubricant clean and the pins free of corrosion. Brake pad guides provide a smooth surface for the brake pads to travel on as they move, and clips put tension where it needs to be so they move as they should.
If any of these hardware components is compromised (or if the caliper pistons that push the pads are not clean), your brake pads either 1) will not contact the rotor as they should, or 2) will not back away from the rotor properly. In one case, your brakes will not engage. You might notice that your vehicle pulls to one side as you brake. In the other case, your brakes will drag and you might feel your car drift to one side while driving. Either way, your brake system is not functioning as it should. Given the brakes are the most important safety feature on your vehicle, that condition is not acceptable.
The complete treatment
Far from being an advertising gimmick or sales ploy, a complete brake service is an important safeguard against faulty brakes. Simply slapping pads on your car does not ensure that the other components close to the end of their useful lives (even though they may “look” okay) will continue to work as they should. A complete repair provides peace of mind.
There is more. Not only might a complete brake job necessitate replacement of rotors and hardware, but the hydraulic brake fluid in your brake system might need replacement as well. Brake fluid is hygroscopic, meaning it absorbs moisture from the air. When that happens, the risk of corrosion increases inside the calipers (or wheel cylinders on drum brakes), steel brake lines, master cylinder, and anti-lock brake system solenoid valves. Corrosion will cause these components to fail. Therefore, vehicle manufacturers recommend replacing the brake fluid as often as every two years or 24K miles. Recommending a fluid flush of the brake system is not unreasonable.
Even a rebuild of your brake calipers and replacement of wheel cylinders is a solid suggestion as your car ages. If you simply add new brake pads to an old worn, leaking, or corroded caliper, the new pads could wear unevenly or seize up. So, sometimes a technician will recommend rebuilding or replacing calipers as part of a complete brake job.
Brake system variables
The components of your brake system do not all wear at the same rate. Mileage markers alone cannot predict when each will need to be serviced. In fact, there are a number of variables that impact how your brake system fares over time.
For instance, your driving habits play a big role. Aggressive braking and driving in stop-and-go traffic will cause your brake pads (and rotors) to wear faster. So will riding your brakes – keeping your foot on the brake pedal when you are not braking. If you drive a truck or large SUV, the weight of the vehicle will make your brakes work harder and wear the pads (and shoes) more quickly, especially if you regularly haul heavy loads or pull a trailer. Driving on dirt roads is really hard on brake system components. The hardware wears faster, as do the calipers, wheel cylinders, rotors, and pads/shoes. And if the environment near you tends to be humid, your brake fluid will need to be changed more frequently.
Only a thorough inspection will reveal the condition of your brakes.
So, a complete brake job might look something like this:
- Inspection of the entire brake system to determine the condition of all its components
- Recommendation of any repairs and replacement necessary to restore your brakes to proper operating conditions for safe driving
- New brake pads/shoes
- Resurfacing or replacement of the rotors/drums
- Hardware replacement
- Rebuild or replacement of calipers or wheel cylinders
- Replacement of hoses, lines, or master cylinder if leaks are present (or malfunction)
- Check condition of the brake fluid and replace if necessary
- Check and adjust the parking brake Test drive to “bed in” the new components
You might be tempted to think you are being misled or “sold” a bill of goods when a repair shop suggests that you consider a complete brake repair rather than a partial one. That is where a relationship with a shop you trust is essential. Oftentimes, whether or not certain brake system components should be repaired or replaced is a judgment call. You want that call to be made by a technician you can depend on. Your brakes are at the top of the list of essential systems on your vehicle. Make sure they remain in excellent order.
Columbia Auto Care & Car Wash | Author: Mike Ales | Copyright
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