Genuine Nissan Quest Brake Booster

Nissan Quest Brake Booster Parts Questions & Answers

• Booster Assy-Brake
  47210-7B000
  Q: How do you perform an operating check and replace the power brake booster on Nissan Quest?

  A: 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, depress the pedal and start the engine; if the pedal goes down slightly, operation is normal. For an airtightness check, start the engine and turn it off after one or two minutes, then depress the brake pedal slowly several times; if the pedal depresses less each time, the booster is airtight. Next, while the engine is running, depress the brake pedal and stop the engine with the pedal depressed; if there's no change in the pedal reserve travel after holding the pedal for 30 seconds, the booster is airtight. When replacing or adjusting the power brake booster, note that these units shouldn't be disassembled due to their complexity and critical relationship to brake performance, so they should be replaced with a new or rebuilt one. Begin by removing the Brake Master Cylinder, then disconnect the vacuum hose from the booster, taking care not to damage it. Remove the trim panel below the steering column and locate the pushrod clevis connecting the booster to the brake pedal; detach the pushrod by removing the retaining clip and clevis pin. Next, remove the four nuts and washers holding the brake booster to the firewall, then slide the booster straight out until the studs clear the holes. Before installing the new booster, measure the distance between the power brake booster and the hole in the clevis, adjusting the clevis if necessary to match the specified length. Apply about 20 in-Hg of vacuum to the brake booster with a hand-operated vacuum pump, measure the length of the output rod, and adjust as needed. Finally, installation is the reverse of removal, and if the Brake Lines were detached from the master cylinder, ensure to bleed the brake system, including the master cylinder.