A: As your brake pads (and shoes, if your rear brakes are drum-type) wear, the pistons in the caliper and wheel cylinders for drum brakes will extend. This will drop the brake fluid level slightly in the master cylinder’s reservoir and is not necessarily a sign of a leak.

Your reservoir will have a minimum- and maximum-level mark. The brake fluid level should be in between these levels at all times. To view this, you may need to remove the lid, if the reservoir is integrated into the master cylinder, as found on older cast-iron designs. Normal wear should not drop the fluid level below the minimum level.

If for some reason the fluid level drops below the minimum level, such as from a leak, this can cause a couple of problems, one minor and one major. At the least, air could be introduced into the master cylinder, which will cause a mushy pedal and an increase in stopping distance. After the leak is found and repaired, the system will need to be bled to remove trapped air and restore braking efficiency. At the worst, you could lose all braking ability, if the reservoir runs dry!

So if you top off the brake fluid, keep in mind you will need to later remove some of the fluid before a “brake job.” That’s because replacing the pads requires compressing the caliper’s pistons, which will push fluid back into the now-overfilled reservoir, making a big mess all over the engine compartment. Use only the type of brake fluid indicated on the lid or in your owner’s manual, such as DOT 3 or DOT 4.

A. Although many brake pad designs incorporate some variation of a brake pad wear indicator, it is best not to rely on this. Brake pads usually wear at a predictable rate, so a great time to inspect them is often when you rotate the tires. You will then have free and easy access to the inside of the caliper for a visual inspection. If you like, you can even use feeler gauges or a brake lining thickness tool (available from online sellers) to measure the pad thickness at each inspection so you can better predict when you’ll be replacing your pads. Although some states’ vehicle inspection programs allow bonded brake linings to be as thin as 1/32,” or less than 1mm, Goodyear Brakes recommends you begin to consider their replacement when their thickness measures in the range of 5/32”-15/64,” or about 4mm-6mm. One common brake pad wear indicator is a metal tab affixed to the inside pad, where most wear usually occurs and the pad is out-of-sight and often out-of-mind. As the pad’s friction material wears, this tab makes contact with the rotor, giving an irritating screech/squeal that means worn pads could be getting dangerously thin. Another brake pad wear indicator is electronic. This type was first used on German luxury cars but is becoming more common among other makes and models. There are a few types of sensors, but on the first, the sensor is embedded in the pad. As the pad wears to the point it is nearing replacement, it will wear away the sensor, breaking the circuit and triggering a warning light on the instrument cluster. This type of pad will include the new sensor embedded in the pad. Other similar sensors are separate parts from the pad and can be reused if they are in good shape. But as with embedded sensors, this type wears through with excessive brake pad wear and must be replaced at the time of pad replacement to restore the warning light functionality.

A: You can put off a check-engine light or “washer fluid low” light. But a brake warning light is nothing to ignore, as it could place you and other drivers’ safety at risk. We’ve just discussed a typical brake-wear warning light, which is different from a simple red brake warning light. Check your vehicle’s owner’s manual to see how your vehicle may be equipped, if you’re unsure. If your parking/emergency brake is working properly, the reason your brake warning light is on is because the brake fluid level is low in the master cylinder, either from normal (although usually excessive) brake pad/shoe wear or a leak. Either reason is serious, and Goodyear Brakes does not recommend driving the vehicle without the cause being checked out.

A: You may be able to reuse the rotors under certain conditions. If the rotors do not have any grooves that can be felt with your fingernail dragging across the surface and you have not felt any shuddering while braking, measure the rotors’ thickness to ensure it can be reused. You may be able to reuse it, but most professional technicians would recommend to have them turned (machined) by a machine shop or auto parts store, if they are thick enough to do so. A resurfaced or new rotor provides a flatter surface to mate to the brake pad, offering quicker break-in and often quieter operation. Rotors that are too thin will not resist warping as well as a new, thicker one. Calipers can be safely reused if they do not show signs of excessive rust or corrosion, leakage or binding. Keep in mind, though, that there is a possibility that a caliper could later leak or bind before the brake pads have reached their expected service life. Buying a complete Goodyear Brakes bundle with new calipers and rotors offers the assurance of longevity and predictable performance.

A: It may be difficult to see, but each rotor should be stamped with its minimum thickness, which will be shown in mm or inches. A dial micrometer is the easiest way to measure this, and don’t be surprised if this is only the first “brake job” and they’re already too thin. Manufacturers in recent years have equipped vehicles with lighter, thinner rotors with less “meat” available to reuse, especially if any grooves are present and machining (often called “turning”) is needed at the local machine shop or auto parts store. For this reason, it makes a lot of sense to consider a complete Goodyear brakes bundle for longevity and predictable performance.

A: Normal wear and heat from operation can cause rubber to degrade in the caliper’s piston outer accordion boot and inner seal, causing leaks. Particularly in areas where road salt and liquid brine are applied during winter months, corrosion can cause the moving parts of the caliper to no longer move smoothly, which can cause a pad to “hang up” and remain applied to the rotor. This can cause rapid wear, of course, and it can also cause the vehicle to pull to one side. This same corrosion can cause the caliper’s piston to pit. Although this damage is not usually apparent – even after peeling back the protective outer boot – it can cut the piston seal and cause a leak. If you have any doubts as to the condition of your calipers, replacing them as part of a complete Goodyear Brakes bundle can offer the assurance of miles of trouble-free driving.

A: The new rotor needs a clean, flat, surface to mate against. This keeps the rotor running without any wobble, which prevents vibration and a shudder in the brake pedal, known as “judder,” that feels like a warped rotor. Clean the hub’s rotor-mounting surface with a wire brush to remove any rust or corrosion. Complete the cleaning process with an aerosol brake cleaner and shop towel.

A: The shape of the brake pad can greatly influence how quiet its operation is. Based on each vehicle’s unique requirements, some pads are chamfered, and some are not. The chamfer means the friction material of the pad, which contacts the rotor, is not completely flat. Instead, the leading and trailing edges are shaped at an angle, a bit like a ramp. This prevents those edges from “biting in” harder than the rest of the pad, which could cause a vibration and noise. Slots machined in the center of the pad reduce stress and eliminate the possibility of cracking the friction material. Years ago, some technicians took it upon themselves to modify the shape of a pad by cutting slots or grinding chamfers into them. The idea may have been sound back then. But if your pads do not include either or both of these features, please don’t be tempted to modify them so they do. Goodyear Brakes engineers have carefully selected the appropriate brake friction material composition and pad shape/design for your vehicle for low noise and optimum performance.

A: Refer to the Goodyear Brakes tutorial on Tools and Safety for complete information, but it is important to follow a “safety first” mantra in each step of working on your vehicle. Select a solid, clear work area, such as a concrete garage floor or pad. Use a sturdy hydraulic jack, not the flimsy scissor jack that may have come with your vehicle, and be sure to use jack stands that are positioned correctly. Look in your vehicle’s owner’s manual or shop manual/online repair information for recommended lifting points. Don’t rely on only the hydraulic jack to hold up the vehicle, as a catastrophic failure of the jack’s seal could mean a sudden release of pressure, dropping the vehicle to the ground—and you, if you happen to be in the way. Wear safety glasses to protect your eyes, and wear mechanic’s or nitrile rubber gloves to protect your hands. Using a torque wrench for every fastener, including lug nuts, ensures you have tightened them to the proper specifications. This prevents the headache of snapping off bolts or stripping out threads, and it keeps your vehicle safe by avoiding a bolt or nut backing out.

A: New brakes require a break-in procedure to evenly transfer the pads’ friction material to the rotors. This is called “breaking in,” “bedding in” or “burnishing.” This will eliminate glazing, which causes noise and reduced performance. Find an empty parking lot and perform the following steps before you hit the highway:

  • Perform 15 stops from 35-40 MPH down to 5 MPH.
  • Allow the brakes to cool for 30 seconds between stops.

Try to avoid panic stops or hard braking for approximately 200 miles.