Changing brake pads or brake rotors might be considered an easier job for the more technically savvy enthusiast. However, as simple as it may be, it’s also quite easy to overlook a few key points that may possibly hinder your system’s performance otherwise. Here are a few things overlooked when changing brakes. Keep these in mind to have better brake performance, feel, and reliability.
Quite a few people tend to miss this step when changing their rotors. More often than not, over the lifespan of a rotor, rust begins to build up at the hub face where the rotor sits. This rust is typical and expected but it builds around the surface features of the rotor.
If the new rotor is simply installed in place without cleaning this rust off, the rotor will not sit completely flush to the hub. A quick drive down the street would reveal a vibration when the brakes are applied and most people would attribute this to warped rotors. The truth is that the rust and debris at the hub-face is interfering with the operation of the brake system.
To avoid this, use some sandpaper, a wire brush, or some steel wool to clean the surface of the rotor hub.
The threads on wheel studs and stud nuts (or wheel bolts and hub threads), like any other mechanical device, are exposed to wear and tear. Whenever you unfasten a stud or bolt, make sure to check the threads to ensure that no cross-threading had occurred and the threads are in good shape.
Make sure the studs or bolts can be loosened and hand tightened with relative ease. If you find that there is significant resistance, odds are the threads have been damaged and may need to be replaced. If all looks good, clean the threads using a bristle brush to remove any visible debris. Do not use any anti-seize compounds or abrasive material for the cleaning as that may interfere with the fastening performance and thread geometry.
For sliding calipers, the sliding pins and boots play a critical role in the operation of the brake caliper. If they do not slide freely, then the brake system will not operate to its full potential and you may find that the feel of the brake pedal may be a little off.
A possible issue that may occur is brake drag. This is when the caliper does not fully retreat when the pedal is released and as such, the brake pad remains in contact with the brake rotor. This may lead to the vehicle pulling in the direction of the engaged rotor and increased fuel consumption. When the sliding pin moves freely, the brake pedal can engage and disengage much easily and you won’t have to worry about the aforementioned issues.
Replace the boots if they are damaged or cracked and replace the guide-pins if they seem damaged (threads are ruined or the shaft is damaged). If the hardware looks good, then clean them, lubricate them using brake lube (synthetic grease), and reinstall them.
In this day and age, pretty much all the cars out there have ABS systems. Given that the ABS system works based on a sensor that reads imprints in the rotor, it is important to ensure the ABS sensor is kept clean and is able to read the rotor. As you use your vehicle, the ABS sensors get exposed to dust and debris. Over time, dirt builds up on the sensor and may end up impeding the full function of the ABS system. It’s important to check the sensor and make sure that it’s unobstructed. If it seems to be dirty, clean it using brake cleaner.
Brake fluid is an integral part of the hydraulic brake system, yet many people forget to check or replace it. Some manufacturers will set schedules for replacement of brake fluid which are based on distance driven or time. However, it’s always good practice to continually keep an eye on it whenever you change your brake components.
If brake fluid gets contaminated by water, air, or debris, heat dissipation may be affected and, in some cases, you’ll start to feel your brake pedals turn to mush. Check that your brake fluid is clean and light in colour. If the fluid is dark and discoloured, you should replace the brake fluid and do a complete flush.
This is one of the most crucial steps of any brake component change. Whenever you install new brake pads or brake rotors or both (new pads and rotors), you MUST complete a bedding procedure. Failure to do so will result in uneven pad deposits on the rotor surface and it will feel like your rotors have “warped”… which is not the case.
The bedding procedure allows the pads to deposit a thin, even layer of material onto the rotor surface and cleans out any debris that may prevent such an even deposit. Here’s our bed-in procedure.