To do an operating check, apply the
Brake Pedal several without starting the engine and engine off to pocket check if there is any variation on the reserve pedal distance then Start the engine and check if the brake reduces slightly. For the airtightness check, switch on the engine and switch it off after one or two minutes then change the brake pedal gently several times; if the depression decreases each time, the booster is leak proof. With the engine running, push down the brake pedal and shut down the engine with the pedal depressed; if after holding it for 30 seconds there would be no return mark on the pedal, the booster is also airtight. When disconnecting the power brake booster units do not disassemble all the components as they are intricate, and require special instruments to assemble, get new or rebuilt ones. First, one must detach the brake master piston after which, for some models, it will be necessary to completely disconnect
Brake Lines crossing in front of the master cylinder. Safely unplug vacuum hose from the brake booster, further, take out the brake pedal return spring at the top of the brake pedal, the clevis pin retaining, and the pin. Fourthly, unlock the four bolts that connected the brake booster to the fire wall and pull out the booster forward till the studs are out of the holes. To install the equipment, it will be done in the reverse manner of the removal process while making sure that the booster mounting nuts have been tightened to the right torque. Some of the procedures include; adjusting the brake pedal height and free play, and bleeding the system if necessary once the master cylinder and brake hoses have been fitted.