Volkswagen Brake Discs

Hard spots, or uneven wear across the brake disc, are caused by excessive heat. While other brake issues can be remedied by resurfacing, this method may not work for such problem because hard spots usually extend below the disc surface. If you try to shave off those high spots to achieve a smooth braking surface, the remaining metal may not be thick enough to ensure proper and safe braking.

Majority of professional brake mechanics recommend rotor resurfacing after brake pad replacement. This is because resurfacing restores the rotor’s flat and even surface, which ensures maximum brake pad friction and minimal vibration during braking. If you use new brake pads on a rotor with grooves, the pads won’t achieve full contact with the brake disc, thus compromising your Volkswagen’s braking performance. It can also cause uneven wear on the new brake pads, therefore decreasing their service life.

You can do away with it by resurfacing your disc using an on-car brake lathe. You can also put on tapered shims in between the brake rotor and the hub. Another way to solve such brake problem is to use conventional bench lathe. Excessive runout means fluctuations on the rotor’s thickness, resulting in vibration. Even just .001 inch of thickness variation can create very noticeable vibration or pulsation in the brake pedal, and this can affect the vehicle’s braking performance if not dealt with properly and immediately.

One cause of rotor distortion is improperly tightening of the lug nuts. This can be prevented by making sure the lug nuts are tightened well and there’s no gap between the rotor and the hub. To avoid creating such gap, make it a point to get rid of the dirt, rust, and other debris on the face of the hub and the inside portion of the rotor hat. You can do the cleaning before rotor installation using a drill-powered brush.

You need to look at several factors when deciding whether to reuse your rotors or not. The first thing you must do is to assess if your rotors can still be resurfaced. If you think they will end up very thin after resurfacing, you’d better have them replaced. If the rotors fitted in your brakes aren’t vented, find out if they’ve been overheated as overheating can cause cracks on the disc, resulting in lateral run-out that will render the rotors useless.

You can wash the disc with warm, soapy water or blast it with brake cleaner to get rid of the metal particles that you’ve shaved off the rotor. After applying brake cleaner, wipe it using a paper towel. If you’ve sprayed warm, soapy water, you need to rinse it and wipe the disc dry. You can repeat this method until the disc surface is smooth and free of any dirt or metal particles.

One way to prevent rust from eating up your brake disc is to apply high-temperature grease to the mating surfaces before installation. This will act as a sealer to help delay corrosion. Remember that in corrosive environments, rust can develop in between the brake hub and the rotor and any rust formation can jack the disc away from the hub, causing runout. So, it’s important that you protect this part before rotor installation rather than dealing with rust issues in the future.