Servicing the brake booster (servo drive) (Nissan Patrol Y60)

Table of contents: Removal ↓ Installation ↓ Functional check ↓ Pusher adjustment ↓

Removal

1. Remove the brake master cylinder from the vehicle.

2. Disconnect the vacuum hoses from the vacuum booster unit.

3. Remove the retaining clip, bend back the tabs of the plastic stop, remove the retaining pin and disconnect the push rod from the brake pedal.

4. Loosen the vacuum booster mounting nuts and, moving the control valve support bracket to the side, remove the booster from the vehicle.

Installation

Installation is carried out in reverse order.

1. Check the correct adjustment of the vacuum booster pushrod, adjust if necessary. Check the height setting and the free travel of the brake pedal, adjust the listed parameters if necessary.

2. Tighten the mounting nuts to the required torque.

Functional check

1. With the engine off, press the brake pedal several times to release the vacuum from the vacuum booster.

2. Lightly depress the pedal and hold it in this position.

2. Lightly depress the pedal and hold it in this position.

3. Start the engine. The pedal should noticeably fall down. Otherwise, you should check the vacuum supply to the block (see accompanying illustration):

Check the vacuum hoses for signs of material aging and other damage. Replace any defective ones.
Disconnect the vacuum hose from the vacuum booster unit and, with the engine idling, check for vacuum by plugging the end of the hose with your thumb.
Disconnect the vacuum hoses, loosen the retaining clamp and remove the check valve from the vacuum booster unit.
Blow into the valve from the vacuum booster side. Air should flow freely.
Try sucking air through the same valve hole. This time the valve should be closed. If any deviations are detected, replace the check valve.

Pusher adjustment

1. Remove the vacuum booster unit from the vehicle.

(The source is published on the portal www.nissanbook.ru)

2. Connect a hand vacuum pump equipped with a vacuum gauge to the hose fitting on the block.

3. Create a vacuum of 500 mm Hg in the booster vacuum tube and measure the amount of protrusion of the tappet A above the master cylinder mounting surface (see accompanying illustration). The nominal value is A = 10.275÷10.525 mm.