How to Change Brake Pads (Front Brake Service Step-by-Step)

With the wheel off and the car safely on jack stands, the first move is the top caliper guide pin bolt. On this Ranger it is a 12mm. Crack it loose with a ratchet, back it out, and the caliper swings open on its bottom pin like a clamshell.

If the caliper is sticky from rust and brake dust, slide a flat-head screwdriver behind the pads and pry gently to break them free. The old pads should drop right out of the bracket. Hold them up next to your new pads - the difference in friction material thickness will tell you everything you need to know about how overdue this service was.

The pads come out without removing the bracket, but the rotor will not. There are two bolts holding the caliper mounting bracket to the steering knuckle - one up high, one down low, both on the back side of the caliper. These are usually 14mm or 17mm and torqued hard from the factory, so reach for the breaker bar to crack them loose.

Do the top bolt first. Once both bolts are out, support the whole caliper-plus-bracket assembly with one hand as you slide it off - it is heavier than it looks and will drop when the second bolt clears. Set it on a milk crate or hang it from the spring. Do not let it dangle on the brake hose.

With the caliper bracket off, the rotor should slide off the wheel studs. If it is stuck from rust on the hub face, give the rotor a few firm taps with a rubber mallet around the outer edge - never strike the friction surface. Old rotors come off, new rotors go on in the same orientation.

New rotors ship with an oily anti-corrosion coating that you do NOT want on your friction surface. Hit both faces and the hat (the middle hub area) with brake cleaner and let it flash off. Once the coating is gone, slide the new rotor onto the studs.

The two bracket bolts that came out get a drop of blue thread locker on the threads before they go back in. Thread locker keeps the bolts from vibrating loose over thousands of stop-and-go cycles, which is what you want on a brake component.

Hand-thread both bolts in before you snug either one - if you torque the top down first, the bottom may not line up. Once both are started, set your torque wrench to 85 ft-lb (verify the spec for your vehicle in the service manual) and torque each bolt in sequence. You will hear and feel the wrench click when it hits the setting - that is the only way to know you got it right.

Old worn pads sat in a caliper whose pistons were pushed out to make up the gap. New (thicker) pads will not fit in that gap until you push the pistons back in. Open your brake fluid master cylinder reservoir cap a quarter turn first - this lets the system breathe so you are not fighting hydraulic back-pressure. Tighten it back up the moment the job is done so moisture cannot get in.

Put an old brake pad against the pistons (so you spread the load instead of cocking one piston) and crank a brake pad compressor tool down on it. A big C-clamp also works in a pinch. On this dual-piston caliper, work each piston a turn or two at a time, alternating sides, so you do not jam one in cocked.

Where the metal backing plate of the brake pad slides against the caliper bracket, you need brake-specific grease. A thin smear in the right four spots - the two ears at the top of the bracket and the two ears at the bottom - stops the squeal you hear from poorly-prepped DIY brake jobs.

Use brake caliper grease (synthetic, high-temperature). Permatex Ceramic Extreme Brake Parts Lubricant or any single-use Bosch synthetic pack works. Less is more here - a pea-sized dab per contact point, smeared thin. Do NOT get grease on the friction face of the pad or on the rotor surface. If you do, hit it with brake clean and start over.

The guide pins are what let the caliper float in and out as the pads wear. If they get sticky from old hardened grease, one pad will wear way faster than the other and you will be back here in 20,000 miles. Pull each pin out, slide the rubber boot off, and wipe the pin and the bore clean with a rag.

Reapply lubricant - but NOT regular grease. Use high-temperature silicone lubricant on the guide pins. Silicone is compatible with the rubber boots and bore seals; petroleum grease eventually swells and degrades them. Spray or smear silicone into the bore, on the pin, and reassemble making sure the boot seats fully into its groove at both ends.

Before you install new pads, look for the wear indicator - it is a small metal tab on the edge of the backing plate that scrapes the rotor and makes a high-pitched squeal when the pads get low. Quality pads (Wagner ThermoQuiet, Akebono ProACT, Bosch QuietCast) include this. If your new pads do not have one, return them and buy a set that does. It is a real safety feature.

The brake pads only fit one way - the angled cut on the friction material lines up with the curve of the rotor. Drop the first pad into the bracket so the wear-indicator tab points inward (against the rotor edge), then the second pad on the other side. Both pads should sit flush against the rotor before you close the caliper.

Swing the caliper closed around the new pads like a clamshell. If it will not close all the way, you either did not compress the pistons enough (back to step 5) or the pads are not seated flush against the rotor. Do not force it - something is not lined up.

The top guide pin bolt goes back in by hand first. On this vehicle, it torques to 20-25 ft-lb. Most cars are in that 18-30 ft-lb range - check your service manual or just hand-tighten and add a quarter turn (about 25 ft-lb on a 3-inch ratchet). Now is the time to retighten the master cylinder reservoir cap if you opened it back at step 5.

Repeat the whole sequence on the other front wheel - pads wear evenly only when you replace them in pairs. When both sides are done, mount the wheels, snug the lug nuts in a star pattern, drop the car off the jack stands, then torque the lug nuts to spec (usually 80-100 ft-lb).