Nissan 47210-CE400 Brake Booster Assembly

Except for model years 2008 G35 Coupe and 2007 G35 Sedan and later, all models need a brake test with the engine off, where you press the brake pedal several times before startup. While engine runs, a small pedal drop after startup signals normal brake operation. To check the booster's airtightness, turn the engine on, wait a minute or two, then turn it off again. After that, press the brake pedal gently three to four times. If pushing three times makes it feel harder than pushing four times, the system is sealed correctly. When the engine is running, press down on the brake pedal and then leave the engine running with the pedal pressed. Keep the pedal pushed for 30 seconds; if the pedal's initial hold remains consistent after this time, it means the booster is sealed correctly. The brake booster has a sealed system and must be replaced with a new or refurbished unit. Turn off the engine, push down on the brake pedal a few times to release trapped vacuum. Unplug battery cables. Unplug master cylinder. Be gentle when separating vacuum lines from the brake booster. Then remove the pin and clevis from the brake pedal booster connection. Take care not to break the small plastic fixture on the end of the clevis pin. Using a jack, lift the booster up to free the mounting screws, then tilt it out of the engine bay over the firewall as the pushrod and mounting bolts clear. You install the power booster by performing the following steps: put new gasket between booster and firewall, set pushrod length if needed, pull vacuum on the booster then measure boost clearance, tighten firewall bolts to their torque specs, put booster pushrod clevis on brake pedal, replace clevis pin if damaged, lubricate moving parts, adjust brake pedal height, bleed brakes, and check brakes back to normal use.

To inspect disc brakes, start by loosening the wheel lug nuts and raising the vehicle securely on jackstands. Remove the wheels to access the two pads in each caliper. Check the pad thickness by looking at each end of the caliper and through the inspection window in the caliper body. If the lining material is less than the thickness, replace the pads. If it is difficult to determine the exact thickness, remove the pads for further inspection. Clean the pads with brake cleaner and re-measure them with a ruler or vernier caliper. Measure the disc thickness with a micrometer to ensure it still has service life remaining. If any disc is thinner than the specified minimum thickness, replace it.