Kia Rio: Brake System / Brake Booster

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.

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 satisfied, the booster performance can be considered as in good condition.

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

Remove the battery and battery tray.

D 1.4 U2 TCI (Refer to Engine Electrical System - "Battery")

G 1.0 T-GDI (Refer to Engine Electrical System - "Battery")

G 1.2 MPI (Refer to Engine Electrical System - "Battery")

G 1.4 MPI (Refer to Engine Electrical System - "Battery")

Remove the air cleaner assembly.

D 1.4 U2 TCI (Refer to Engine Mechanical System - "Air cleaner")

G 1.0 T-GDI (Refer to Engine Mechanical System - "Air cleaner")

G 1.2 MPI (Refer to Engine Mechanical System - "Air cleaner")

G 1.4 MPI (Refer to Engine Mechanical System - "Air cleaner")

Remove the brake fluid from the master cylinder reservoir with a syringe.

Do not spill brake fluid on the vehicle as it may damage the paint. If brake fluid comes in contact with the paint, wash off immediately with water.

Disconnect the brake fluid level switch connector (A), and disconnect the brake tube (B) from the master cylinder by loosening the tube flare nut.

Remove the master cylinder (B) from the brake booster after loosening the mounting nuts (A).

Remove the crash pad lower panel.

(Refer to Body - "Crash Pad Lower Panel")

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

Remove the brake booster mounting nuts (A).

Remove the brake booster after disconnect the vacuum hose (A) and ISG connector (B).

Inspect the check valve in the vacuum hose, intensifier and the connecting section.

Do not remove the check valve from the vacuum hose.

Check the boot for damage.

Install in the reverse order of removal.

• Before installing the pin, apply the grease to the joint pin. • Use a new snap pin whenever installing.

After installation, bleed the brake system.

(Refer to Brake system - "Brake System")