
1. Reservoir cap
2. Reservoir
3. Brake booster
4. Master cylinder
5. Push rod
1.Run the engine for one or two minutes, and then stop it. If the pedal depresses fully the first time but gradually becomes higher when depressed succeeding times, the booster is operating properly, if the pedal height remains unchanged, If there is no change in pedal stroke, check valve, vacuum hose and booster need to be checked.

2.With the engine stopped, step on the brake pedal several times.Then step on the brake pedal and start the engine. If the pedal moves downward slightly, the booster is in good condition. If there is no change in pedal stroke, check valve, vacuum hose and booster need to be checked.
3.With the engine running, step on the brake pedal and then stop the engine.Hold the pedal depressed for 30 seconds. If the pedal height does not change, the booster is in good condition, If there is no change in pedal stroke, check valve, vacuum hose and booster need to be checked.

1.Turn ignition switch OFF and disconnect the negative (-) battery cable.
2.Remove the battery and battery tray.(Refer to Engine Electrical System - "Battery")
3.Remove the air duct and air cleaner assembly.(Refer to Engine Mechanical System - "Air Cleaner")
4.Remove the master cylinder.(Refer to Brake System - "Master Cylinder")
5.Remove the fixing clip and the vacuum hose (A) from the brake booster.

6.Disconnect the brake booster vacuum pressure sensor connector (A).

7.Remove the snap pin (B) and the clevis pin (A).

8.Remove the brake booster (B) after loosening the mounting nuts (A).
Tightening torque :16.7 - 25.5 N.m (1.7 - 2.6 kgf.m, 12.3 - 18.8 lb-ft)


1.Inspect the vacuum hose.
2.Check the boot for damage.
1.Installation is the reverse of removal.
• Before installing the pin, apply the grease to the joint pin.
• Use a new snap pin whenever installing.
2.After installation, bleed the brake system.(Refer to Brake System - "Brake Bleeding Procedures")
3.Check the brake oil leakage and pedal operating condition.
Repair procedures
Master CylinderHyundai Tucson (NX4) 2022-2026 Service Manual: Battery
- Description
CMF Battery
The CMF (Closed Maintenance Free) battery is, as the name implies,
totally maintenance free and has no removable battery cell caps.The CMF
(Closed Maintenance Free) battery does not require water replenishment
for the repair.The battery is completely sealed, excep ...
Hyundai Tucson (NX4) 2022-2026 Owner's Manual: Key Ignition Switch
WARNING
To reduce the risk of serious injury or
death:
Never allow children or any person
who is unfamiliar with the vehicle to
touch the ignition switch or related
parts. Unexpected and sudden vehicle
movement may occur.
Never reach through the steering
wheel for the ignitio ...