Kia Sorento: Brake Booster Repair procedures

Kia Sorento (MQ4, 2021-2026) Service Manual / Brake System / Brake System / Brake Booster Repair procedures

Brake Booster Operation Test

For simple checking of the brake booster operation, perform the following tests.

1.	Run the engine for one to two minutes, and then stop it. If the pedal depresses fully initially but gradually becomes higher in the successive attempts, the booster is operating properly. If the pedal height remains unchanged, the booster is inoperative.

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, the booster is inoperative.

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, and if the pedal rises, the booster is inoperative.

If the three tests above are met,, the booster performance can be considered as in good condition.

Even if one of the three test above are unsatisfactory, check the check valve, vacuum hose and booster for malfunction.

Brake System — Brake System / Brake Booster / Repair procedures / Brake Booster Operation Test illustration

Removal

1.	Remove the battery. G 2.5 GDI THETA III - (Refer to Engine Electrical System - "Battery") G 2.5 T-GDI THETA III - (Refer to Engine Electrical System - "Battery")

2.	Remove the ECM bracket assembly. G 2.5 GDI THETA III - (Refer to Engine Control / Fuel System - "Engine Control Module (ECM)") G 2.5 T-GDI THETA III - (Refer to Engine Control / Fuel System - "Engine Control Module (ECM)")

3.	Remove the Master Cylinder. (Refer to Brake System - "Master Cylinder")

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

5.	Remove the fixing clip (A) and separate the vacuum hose (B) from the brake booster.

6.	Remove the brake pedal split pin (A) and the clevis pin (B).

Remove the fixed nuts (A) and then remove the brake booster (B).

Tightening torque :

16.7 - 25.5 N·m (1.7 - 2.6 kgf·m, 12.3 - 18.8 lb·ft)

Brake System — Brake System / Brake Booster / Repair procedures / Removal illustration

Inspection

Inspect the vacuum hose.

Do not disassemble the check valve in vacuum hose.

2.	Check the boot for damage.

Installation

Install in the reverse order of removal.

•	Before installing the clevis pin, apply grease.

•	Use a new split 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.

Brake Booster Components and Components Location

Components 1. Reservoir cap2. Reservoir3. Master cylinder 4. Brake booster5. Push rod6. Vacuum sensor...

Master Cylinder Components and Components Location

Components 1. Reservoir cap2. Reservoir3. Master cylinder 4. Brake booster5. Push rod6. Vacuum sensor...

Kia Sorento: Brake Booster Repair procedures

See also:

Manuals list