Nissan D7210-3BA0A Master Vacuum Assembly

To perform an operating check, depress the brake pedal several times with the engine off to ensure there's no change in the pedal reserve distance, then start the engine and depress the pedal; a slight drop indicates normal operation. For an airtightness check, start the engine and turn it off after one or two minutes, then slowly depress the brake pedal several times; if the pedal depresses less each time, the booster is airtight. While the engine is running, depress the brake pedal and stop the engine with the pedal held down; if there's no change in pedal reserve travel after 30 seconds, the booster is airtight. When replacing the power brake booster, which should not be disassembled due to its complexity and critical role in brake performance, first remove the air filter housing for clearance, then take out the master cylinder and cowl cover along with the strut brace. Disconnect the vacuum hose from the booster, remove the safety clip and pin from the clevis to detach it from the brake pedal, and take out the four mounting nuts securing the booster to the firewall before removing the booster from the engine compartment. Measure the booster input rod length before installing the new booster and adjust if necessary. Installation follows the reverse order of removal, ensuring a new gasket is used between the booster and the firewall. For adjustment, measure the distance between the power brake booster and the hole in the input rod clevis, compare it to the specified dimension, and if needed, loosen the adjusting nut to turn the clevis to the correct length before connecting it to the brake pedal and tightening the nut securely.