preparing your car for winter driving

How An Auto Service Shop Resurfaces Your Rotors With A Brake Lathe

Posted on: 18 January 2016

As brake pads wear down, the metal rivets that hold the pads to the bracket become exposed. Exposed rivets will dig into the surface of the brake rotor and create grooves in it which negatively affects the ability of the car to slow down and stop. You can tell when the rotor is going bad because your brake pedal will start to feel like it's fluttering when you press down on it to slow your car down – especially when you are traveling at high speeds. To correct the problem, the brake rotor needs to be resurfaced to make it smooth again. Here is how an auto shop can resurface the rotor with a brake lathe.

Determine Rotor Surface Thickness

The auto shop will first check the minimum required rotor thickness level for your car. The minimum thickness level for a rotor varies depending on the car model, but there is a point where a rotor can wear down enough that it can't safely be resurfaced. The mechanic will measure the thickness and determine if it still meets manufacturer's guidelines. If the rotor does not meet the guidelines, the mechanic will not be able to resurface the rotor.

Resurfacing the Rotor

The machine shop operator will take the rotor and put it on a brake lathe. The brake lathe is designed to spin the rotor around at a high speed while two metal bits trim the surface down so it is completely smooth again. Here is how the brake lathe works:

Step One: The rotor is placed onto a shaft on the lathe and held in place with a large mounting bolt and nut.

Step Two: The machine operator will place a rubber strap around the outside edge of the rotor. The rubber strap helps to reduce the loud noise a rotor makes when it spins around on the lathe.

Step Three: The operator will then set the metal blades so they are barely touching the surface of the rotor. If the blades dig too far down into the rotor, it could thin the surface too much and render the rotor useless.

Step Four: The machine is turned on so the rotor spins around quickly as it is automatically fed between the two blades.

Step Five: The blades move across the rotor to trim it down until there is  a nice shiny finish that is smooth to the touch.

Step Six: The rotor is removed and handed back to you so you can put it back on your car or it is placed back on your car for you. To learn more, speak with a business like Vince's Auto Service.

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