In a Nissan Altima, or any vehicle, replacing a brake caliper is a risky task. Such maintenance is often best recommended for a trained mechanic. Should you look to replace a caliper yourself, take it up with such an expert beforehand.
Take off the wheel for the caliper you must replace. Make sure the car is securely on the jack stand before you do this.
Disconnect the parking brake cable and lock spring if you're replacing a rear caliper. Disconnect and plug the brake hose, tossing out the washers that were attached with the flare nut.
Unscrew and remove the caliper pin bolts so you can remove the caliper. It should pivot up away from the rotor or bracket and slide inboard off the pin sleeve.
Remove the brake pads, shims and pad springs.
Make sure the new caliper's piston is completely in the caliper body. Turn the piston clockwise back into the caliper if it isn't. Avoid damaging the piston boot.
Coat the mounting support with a silicone based grease where the pad makes contact. Install new pads with the shims and pad springs.
Install the caliper into position. The pin bolts should be torqued between 16 foot pounds and 23 foot pounds.
Connect the brake fluid hose. Use new copper washers with the flare nut. The nut should be tightened to 12 foot pounds to 14 foot pounds.
Reattach the lock spring and parking brake cable to the rear caliper.
Bleed the brake system to remove air from it. Attach a transparent hose to the open bleeder valve and have another person depress the brake pedal. Close the valve, let the brake retract and repeat until all air is gone.
Replace the wheel and lower the vehicle. Pump the pedal several times to seat the brake pads, then test the brakes on the road.
