Adjusting Brake Pedal Height and Free Play

Finding Your Proper Pedal Free Play

Most pedals (brake and clutch) should have a small amount of free play. Free play is the distance the pedal can be pressed before it makes contact on the other end. It's very small, usually less than 10mm.

What You'll Need:

- ruler

- open end wrenches

- line wrenches

- pliers

- Wite-Out or another way to mark a metal surface

To test your pedal free play, it's best to use your fingers. Move the pedal up and down and you'll be able to feel the looseness. You may be able to tell by hand when the free play is right. To be mathematical about it, all you need is a ruler. Place one end of the ruler against the floor and the other alongside the pedal. Lift the pedal to the top of its range and note the measurement. Now push the pedal just far enough for it to make contact on the other side (the end of the free play) and not this measurement. Subtract measurement two from measurement one and this is your free play amount.

Adjusting the Pedal Height and Free Play

Now that you know which way you need to go with your adjustment, you're ready to fine tune the pedal height and free play. Follow the pedal upward to the point it attaches to a rod, called the push rod. Before you touch anything with your tools, it's a good idea to mark the pushrod with your Wite-Out. You just need a dot on the part that's facing down toward you. This dot will let you be sure you don't rotate the push rod until you want to. Any rotation ahead of time will throw of your measurements.

Now locate the locking nuts for the push rod. In the application pictured below (a Honda) there is a 12-pt star nut and a hex nut. Here's where your line wrenches come into play. Slip a line wrench over each of the lock nuts and loosen by turning them in opposite directions. Don't let the push rod rotate yet (if it does rotate a little, use your mark to bring it back.

With the lock nuts loosened, you can rotate the push rod. As it rotates, the pedal free play will increase or decrease slowly. You may need pliers to grip the push rod tight enough to rotate it.

When you have the pedal free play adjusted, tighten the lock nuts and drive around the block. Retest the pedal height to be sure.