Checking and Changing Brake Pads


Checking Brake Pads

[KS] If you’re not sure about how to do this, ask your favorite “car nut” to show you. Most such folks can show you how, even if they’re not familiar with the NSX. Just show them these instructions.

Stand above the wheel, looking down through the spokes of the wheel to the top of the caliper (the big metal holder on the side of the rotor, which is the big metal disk inside the wheel). A flashlight will help.

At the top, inside the caliper, you will see the edge of the brake pad. The brake pad consists of two pieces, both of which are flat and you’re looking at the top edge of them. One is called the “backing plate” and is a piece of metal about a quarter of an inch thick. The other, the stuff between the backing plate and the rotor, is called the “pad material.”

When brake pads are new, the pad material is about 50 percent thicker than the backing plate. When the pad material is about half as thick as the backing plate, it’s time to replace the pads. If it gets any thinner than that, you will start to hear a squeaking sound (which you might hear even when you are not stepping on the pad), which is the metal tab that others have posted about (but which you can’t see without taking off the wheels).

Replacing Brake Pads

[BSD, AW, DG] The following assumes you know basic concepts.

  • Get and read shop manual
  • Loosen front lugs just a bit
  • Raise car, support on jack stands
  • Remove wheels
  • Remove brake reservoir lid
  • Remove (2) bolts holding brake line to suspension
  • Remove (2) bolts holding caliper to caliper holding bracket
  • Rear: Remove cover around parking brake cable in
  • Read: Pull parking brake cable out of the way
  • Rear: Remove “clip-pin” and through-pin holding parking brake cable to caliper assembly. (Make sure parking brake is off.)
  • Remove (2) bolts holding caliper to caliper bracket. Be careful not to loosen the banjo bolt (same size, 25 lb-ft) instead of the lower caliper mounting bolt.
  • Remove caliper from rotor and bracket and support from A-arm with coat hanger (at the front you can rest the caliper on the upper A-arm. Just don’t knock it off.) You may want to use large screwdriver and pry caliper outward to compress caliper piston first. Pads will remain in bracket. Do not stretch, flex or crimp brake hose.
  • Remove pads from bracket. Don’t be surprised if the inner pad falls out on the ground immediately. Inspect. Pads should have a minimum thickness. (Spec in book.) Pads should be worn down evenly. I replaced mine with a little less than 1/2 the material left so now I have an emergency set.
  • Inspect caliper. Look for fluid leaks, cracks. Look at piston and piston boot. Should be free of cracks and not leaking.
  • Lightly grease shims on internal surfaces (ends of pad backing plates and ends of caliper where parts slide against each other). Do NOT get grease on pad surface. Be sure to use a high temperature grease.
  • Insert new pads (with shims) into bracket.
  • Front – use large C-clamp or brake piston retracting tool (available at any parts store) to compress pistons in caliper. I put a pad in the caliper and press against the pad with my C-clamp. Press the piston way back. When you do this, make sure the master cylinder doesn’t overflow (as a precaution you can remove a couple ounces of brake fluid beforehand).
  • Rear: To get the piston to retract into the caliper on the rears, turn the piston clockwise by inserting a straight metal tool (I used a metal straight-edge) into the slots in the piston and twisting.
  • Put caliper back on rotor and in bracket, over pads. It’s easy to bend this little tabs on the shims when replacing the caliper; look carefully as you reassemble.
  • Replace caliper bolts (36 lb-ft)
  • Rear: Replace parking brake cable, pin, and cover.
  • Replace brake line bolts (16 lb-ft)
  • Bleed Brakes
  • Replace brake reservoir lid
  • Replace wheel and torque (80 lb-ft)
  • Lower car
  • Test carefully

Hints/Warnings/Cautions:

  • Don’t get grease on brake pad friction surface
  • Don’t let caliper dangle from brake line
  • Do inspect brake lines, calipers, pistons and boots for wear
  • Do inspect brake pads for even wear
  • Don’t breath any of the dust; it may contain asbestos. For the same reason, don’t blow it off with compressed air. If necessary, wash it off with brake cleaner or something.
  • Wear surgical gloves to obviate later cleanup
  • If you’re using an impact driver, as specified in the manual, the bolts shouldn’t be a problem. If you’re using a screwdriver, you’re using the wrong tool.