Volvo's XC70 comes standard with all-wheel, anti-lock disc brakes. The braking system uses a combination of brake pads and rotors being forced together by fluid-driven caliper pistons. The brake pads are designed with metal wear indicators that reach the surface of the rotors when the pads have been worn to a thickness worthy of replacement. If you hear the squeal from the wear indicators making contact with the XC70's rotors, you should replace the brake pads as soon as possible.
Park the Volvo on a relatively flat surface and turn the engine off. Pull the hood release and apply the parking brake. Move to the front of the vehicle.
Lift the bonnet. Locate and remove the cap from the master cylinder. The master cylinder holds the XC70's supply of brake fluid, and is located to the right of the Volvo's engine. Remove half of the fluid from the reservoir with a poultry baster and lay the cap over the container's opening.
Loosen the lug nuts on each wheel corresponding to the brake pads you will be changing, using a tire iron or lug wrench. Target replacement on both wheels on the axis: If the brake pads on one side of the vehicle require replacement, be sure to replace the pads on the opposite side to maintain balance.
Lift the Volvo with the jack and rest the axles of the vehicle on two jack stands. Move the jack out of the way.
Remove the lug nuts and take the wheels/tires off.
Remove the retaining clip from the outside of the caliper with a pair of pliers or a flathead screwdriver. The caliper brackets the rotor on the side of the disc closest to the rear of the Volvo. Use chain lubricant on the spring-loaded retaining clip, if it will not easily pull from the caliper. You will need to reinsert the clip, so be careful not to bend it during removal.
Remove the rubber caps over the two caliper pins on each caliper, by hand. Keep track of the caps, as you will need to replace them once the pads have been changed.
Remove the two caliper pins with a 7-mm Hex socket and ratchet. Inspect the pins for rust and dried brake grease. Clean each pin with brake parts cleaner and a towel (or wire brush for more stubborn substances) and apply a thin layer of brake grease to the threads.
Lift the caliper from the XC70's caliper bracket. Suspend the caliper from the steering arm above the brake assembly, using a wire coat hanger or bungee cord, or lay it on top of the brake rotor. Do not let the caliper hang from the connected brake line.
Slide the worn brake pads from the caliper bracket. Check the caliper bracket, specifically the "brake pad mating surfaces," where the pads sit inside the bracket. Remove any rust or other obstructions with brake cleaner and a wire brush.
Slide the new brake pads into the slots of the bracket.
Retrieve the caliper from above the brake assembly and place a C-clamp over the piston and the back side of the caliper. The piston is the cylinder that protrudes from the inside of the caliper--it is responsible for forcing the brake pads against the rotor during braking. The pistons are shrouded within a dust cover made of rubber. Be careful when clamping the pistons, so as to not tear the covering.
Squeeze the piston into the side of the caliper with the C-clamp to make room for the new brake pads. Remove the clamp when the rim of the piston is flush against the inside of the caliper.
Replace the caliper over the newly installed brake pads and screw in the caliper's pins. Tighten the pins with the 7-mm socket and ratchet.
Insert the retaining clip into the slots on the outside plane of the caliper.
Repeat steps 6 through 15 for each additional set of brake pads that require replacement.
Return the Volvo's wheels to the wheel bolts and screw on the lug nuts by hand.
Lift the vehicle with the jack and remove the two jack stands. Lower the tires to the ground. Tighten the lug nuts in staggered order (skipping at least one lug nut as you tighten them), using the tire iron or lug wrench. Return to the engine compartment.
Remove the master cylinder cap once again and check the level of brake fluid. Place a funnel inside the reservoir and fill the container with brake fluid, as necessary. Return to the driver's seat.
Start the engine and press the brake pedal slowly, until it is completely depressed to the floor. Relieve pressure slowly and repeat the depressions until the pedal response becomes normal. This will inject brake fluid into the caliper and reset the caliper pistons. Return to the engine compartment.
Check the level of brake fluid in the master cylinder. Add fluid, as necessary. Remove the funnel and replace the master cylinder cap. Close the Volvo's bonnet.