Brakes. Who needs ’em? They just slow you down anyway. At the track, you can boil your brake fluid, crack your rotors, wear out brake pads and more! Sounds like fun right? You’re going to need to know how this stuff works. Check out this page for a demonstration of replacing and servicing brake components.
Tools: Needle nose pliers, regular pliers, ratcheting wrenches and bits
Suggested: brake cleaner, penetrating agent, plastic gloves, brake bleeder and bottle
Demo car: 2008 STi
- Loosen lug nuts. If you jack up the car first you will want someone to depress the brake pedal so the wheel does not turn while you are loosening the lugs.
- Jack up the corner of the car you want to work on and place a jack stand somewhere safe. Things can and do shift, especially when you are working at the track (just ask my poor door panels and side skirts).
- Remove the wheel from the car and hose down your brakes with brake cleaner (makes it easier to remove parts). If you are removing the brake caliper you will also want to spray penetrating agent on the caliper bolts now as they are often very heat cycled and will be difficult to remove.
- Your brakes can literally get up to 1000 F; so, it’s a good idea to do this when they are cool. This might be a good time to let that happen. You have been warned.
- Using the needle nose pliers, remove the cotter pins holding the retaining dowels in place.
- Use the needle nose pliers or a punch to push the retaining dowels back. They will be under pressure from the spring-loaded clip; so, it may be helpful to push down on the clip while performing this step.
- Once you have removed one dowel, remove the clip and the other dowel should slide out easily.
- Pinch the pads back from the rotor to force the pistons to retract into the caliper. Then wiggle out the pad. Perform the same for the other side.
- Using your wrench, undo the two caliper bolts holding the caliper in place. You will want to have something handy (I keep a spare jackstand) to support the caliper in such a way that it does not place pressure on the line. The caliper will rotate off the rotor.
- Insert a bolt into the hole on the rotor and use your wrench to tighten. This will push the rotor off the hub.
- Slide the rotor off and and slide the new rotor on.
- Reattach the caliper and torque down the caliper bolts.
- Prepare the brake pad. I like to use a backing plate because it can help with heat deflection. Heat is your biggest enemy at the track as far as your brakes are concerned. Also, if the car is to be used on the street, I will spray some brake lube on both sides of the backing plate, which supposedly quiets down the brake noise.
- Using a screw driver or pliers, push one piston all the way into the caliper. Try not to puncture the caliper seals when you do this. You can use the brake rotor for leverage.
- Once the piston is retracted, insert the pad at an angle so you can hold it back while you use the screwdriver or pliers to push the other piston back. If you don’t do this, the piston will keep extending when you push the alternate piston in.
- Once you have the far pad in, insert the dowels to hold is in place while you insert the near pad. I usually try to put the pad with the most wear or a visible wear tab on the near/outside position so I can monitor brake pad wear more easily.
- Place the clip back in the correct position and completely insert one of the dowels. You will need to hold the clip down to work the other dowel through. I use a wrench to tap the dowel the last inch since the clip applies pressure. Wiggle the pads as you do this so things line up. Also, make sure your cotter pin holes are pointed outward or you will have to pull the dowels back out and re-orient them to get the cotter pins in.
- Insert your cotter pins and give everything a final spray of brake cleaner.
- Reattach the wheel and torque it down to 80 – 100 ft/lbs (I do 80).
- Bed the pads in using your preferred procedure. I usually just drive around for a bit and brake really hard a several times, but different materials may require a stricter regimen than others.
Bleeding Brake Fluid
- Remove the rubber cover to expose the bleeding nipple and place a wrench on the bleeder with a plastic rubber tube attached to the nipple.
- Using a brake bleeder or friend, pressurize the hydraulic fluid in the brake lines. I attached my brake bleeder to the fluid reservoir and keep it pressurized around 15 psi using the hand pump on the bleeder. Alternatively, your friend can pump your brakes for you, but if you do that make sure to keep your reservoir topped off or you will let air into the system.
- Loosen the bleeder valve and let the fluid flow throw the hose into a bottle or cup or whatever you use. This stuff is bad for paint so watch where it goes.
- If I’m just looking for firmer pedal feel, I’ll bleed a few inches of fluid into the line. If I’m swapping fluid I will look for a color change.
- Follow the bleeding order for your particular brake system. I believe the Subaru used here is Left Front, Right Rear, Right Front, Left Rear. Also, this Subaru has an insider bleeder valve that should be bled before the outside valve on each brake.
- If your peddle gets mushy at the track, you probably boiled your fluid. This can be scary depending on when it happens. The good news is most of your pedal feel will return when things cool down, but to get back to A+ pedal feel, bleed some fluid!
Attack the Track and it’s related affiliates assume no liability for the accuracy or inherent risk associated with these instructions. This website publishes information for demonstration purposes only. The instructions do not apply to all vehicles and are application specific. Always use a qualified mechanic, ideally one proficient with your vehicle.