Genuine Mazda Protege Brake Booster

Mazda Protege Brake Booster Parts and Q&A

• Brake Booster
  GE4T-43-800
  Q: How to perform an operating check and air tightness check on a power brake booster on Mazda Protege?

  A:

  To conduct an operating check, step on the brake pedal several times when the engine is not operating, and be sure that there is no alteration in the distance to the pedal reserve. Turn on the engine with the depressed pedal, when the pedal goes down a little, the engine is working normally. To check air tightness, start the engine and turn it off after one or two minutes and depress the brake pedal slowly several times, the slower the pedal is depressed the more certain it is that the booster is airtight. When the engine is switched on, press the brake pedal and turn the engine off holding the pedal down; in case there is no alteration in the reserve travel of the brake pedal after 30 seconds, the booster is airtight. When the air tightness check fails, recheck or replace power brake booster vacuum hose and check valve then repeat air tightness check. The power brake booster units are not to be broken down since they require special tools, they may be replaced by new or rebuilt ones. Disconnect booster vacuum hose /check valve without damaging the hose. Take out the steering column lower finish panel, the Brake Master Cylinder and the pedal return spring. Find a push rod clevis that attaches the booster to the brake pedal, unscrew the retaining clip and clevis pin and then unscrew the four nuts that join the brake booster to the firewall. Slide the booster straight away to avoid breaking the gasket. To install, do the opposite of uninstalling, screw the booster mounting nuts into place accordingly and fit a fresh clevis retaining clip as required. When putting the vacuum hose/check valve in, make sure the arrows on the hose are facing towards the engine. In case the power brake booster unit should be changed, clearance between the master cylinder piston and the push rod in the booster should be measured and adjusted to have minimal clearance to prevent brake drag or a hard-travelling pedal. Lastly, once the master cylinder has been installed along with the Brake Hoses, the brake pedal height and free play should be adjusted and the brake system bled.