K - Excessive Brake Pedal Effort

K1 CHECK BRAKE APPLICATION
With the engine "OFF", apply and release brake pedal five times to deplete all vacuum from the Power Brake Booster. Depress brake pedal, hold with light pressure. "START" engine. Does the brake pedal hold?
YES - Go to K2.
NO - Go to K4.

K2 VACUUM BOOSTER LEAK TEST
- Run engine to medium idle.
- Release accelerator pedal and turn engine "OFF".
- Wait 90 seconds and apply brakes. Two or more applications should be power assisted.
- Does power brake booster work?
YES - Vehicle OK.
NO - Go to K3.

K3 POWER BRAKE BOOSTER CHECK VALVE TEST
- Disconnect vacuum hose for power brake booster check valve at manifold.
- Blow into hose attached to power brake booster check valve. Does air pass through.
YES - Install a new Power Brake Booster Check Valve and repeat step K2.
NO - Replace power Brake Booster. Repeat K1.

K4 BRAKE PEDAL LINKAGE TEST
Detach booster push rod from pedal pin and depress brake pedal fully. Did pedal move freely?
YES - Go to K5
NO - Service or replace brake pedal bushings.

K5 BRAKE PRESSURE CONTROL VALVE CHECK
Check Brake Pressure Control Valve for contamination. Is fluid contaminated?
YES - Replace brake pressure control valve. Fill brake master cylinder reservoir. Repeat K1.
NO - Go to K6.

K6 POWER BRAKE BOOSTER CHECK VALVE VACUUM TEST
- Disconnect vacuum hose from power Brake Booster Check Valve.
- Run engine at "IDLE". Check vacuum supply with a vacuum gauge.
- Is vacuum greater than 12 in (40.5 kPa) with brake booster non-operational?
YES - Replace power Brake Booster.
NO - Service or replace vacuum hose and vacuum fittings. Also tune or service engine as required.