Horsepower is the most common measure of performance, but brakes are just as important, whether you're at the track or just dealing with your City's heavy commuter traffic. The rotors play a critical roll in your TSX's braking system by working with the pads to stop your vehicle while managing the heat of repeated stops to ensure consistent performance. How does wear and tear on your rotors affect your car's brakes, and how do you replace them?
What Does a Rotor Do?
The rotors fit over the hubs on your TSX, spinning with the wheels as you drive. When you apply the brakes, you're forcing brake fluid into the pistons of the brake calipers. As they extend, they push the brake pads into the rotors. The friction between the pads and the rotors slows down the vehicle.
That friction creates a tremendous amount of heat, which is absorbed and dispersed by the rotor. The metal acts like a giant heat sink, giving the heat generated from a stop time to dissipate. As the brakes are used, the metal wears down, slowly decreasing the amount of thermal mass available. With less metal to spread the heat, the rotor temperature will be higher after each stop. These temperatures can get high enough to cause the pads to warp. In turn, the uneven surface of the pads will cut into the rotor, leaving grooves. This mismatch of surfaces decreases pad to rotor contact, reducing the effectiveness of the brakes.
Front rotors are made of two metal discs with a series of vents in the center. As the rotor spins, these vents pull in air, cooling down the discs. Some versions of the TSX also have ducts that direct fresh air to the rotor to further aid cooling. Rear brakes are responsible for a lot less of the braking force, so Acura designed this car to use a pair of solid metal disc with no venting. They're still able to stay cool under spirited driving, and this design decreases unsprung weight for a better ride.
When Do I Need to Replace the Rotors?
Rotors should be replaced when they are at or near the minimum thickness, which is stamped on the rotor between the hub and the disk. Measurements should be taken at multiple points on the braking surface, as thickness can vary significantly due to warping. Since the brake pads don't contact the outer edge of the rotor, this area won't wear down, leaving a lip.
Rotors should be always machined when replacing the pads to provide a flat surface for optimum contact. Typically, machining removes about 0.015 inches (0.4 mm.) If taking this much metal off would put the rotor under the minimum thickness, it should be replaced.
Contrary to popular belief, the minimum thickness has nothing to do with the performance of the rotor. It's actually the thinnest the rotor can be to allow the rotor and brake pads to make contact. If the pads are worn and the rotor is too thin, the caliper pistons won't be able to push these parts together to brake. However, a thin rotor is far more likely to lead to warping of the pads and rotor surface.
What Do I Need to Replace a Rotor?
Along with common hand tools, a jack and a set of jack stands, there are a couple more items you should have to complete this job:
An impact screwdriver – This tools uses a spring mechanism to turn a hammer strike into a rotation, spinning the bit. Since it's turning the bit while under the pressure of the hammer, it all but ensures the screw will turn without the head becoming stripped.
Brake cleaner – The new rotor will be covered in a rust preservative that need to be removed using brake cleaner before installation.
A wire brush – While not required, it's a good idea to clean off the surface of the hub before installing the new rotor.
Most of the steps used to replace the rotors are also used when replacing brake pads. If you need new pads, you may as well do both jobs at once.
How do I Replace the Rotors on My TSX?
Lift the car onto a set of jack stands and remove the wheels.
Unbolt the brake caliper. Slide it off the caliper bracket and hang it up out of the way using a bungee cord or piece of wire so that the weight of the caliper isn't pulling on the brake hose.
Slide the brake pads out of the caliper bracket. Take note of their orientation so you can slide them in the same way when you put everything back together.
Unbolt the caliper bracket and set aside.
The rotor should be held in by two screws on the surface near the wheel studs. These can be very tight and easy to strip, but they can be loosened safely with an impact screwdriver.
The rotor should slide off of the hub center and studs. Use the wire brush to remove any rust that has formed on the hub face, taking particular attention to the areas around the wheel studs.
Slide the new rotor onto the studs and reassemble the brakes in reverse order.
I Removed Everything and My Rotors Won't Come Off. Now What?
The rotors can rust to the hub, making them difficult to remove. If this happens, spray around the studs and hub center with a penetrating oil. If the rotor still won't come off, get a pair of bolts that have the same width and threading as the rotor screws. Screw these into the screw holes to apply pressure between the rotor and hub.
The TSX uses a “drum in hat” parking brake system, which means the rotor extends behind the hub and uses the inside as a drum for the parking brake mechanism. If the parking brake is engaged, the shoes inside the parking brake will clamp onto this drum and keep the rotor from moving. Over time, wear to this drum section can form a lip that can hang up on the brake shoes inside. If the parking brake isn't engaged and the rotor is still stuck, you may need to loosen the adjuster to move the shoes in. At the front of the rotor, there's a small rubber plug that can be removed to access the brake adjuster. Use a screwdriver to screw the adjuster in, which will bring the shoes closer together so they don't make contact with the back of the rotor.
Where Can I Get a High Quality Replacement Rotor for My TSX?
When you want the highest quality, best performing rotors for your sports sedan, it's hard to beat an OEM part. They're made by Acura using the same designs and materials they used at the factory, so you know you'll get the same braking performance. Where can you get these rotors? AcuraPartsNow.com. We make it easy to find what you want by letting you search for parts by part numbers, models, VINs and keywords like “rear” and “wagon.” Have questions about your application? We have factory-trained parts personnel available to answer them.