E21-6006 | Genuine Paccar® Brake Foot Control Pedal

1. Soft or Spongy Pedal Feel

Symptom: Pedal feels soft, mushy, or spongy when pressed.
Possible Causes:
Air in hydraulic lines (in hydraulic systems)
Internal brake valve or master cylinder leak
Pedal pivot or linkage binding

2. Pedal Goes to the Floor

Symptom: Pedal slowly sinks to the floor under steady pressure.
Possible Causes:
Hydraulic leak
Bad master cylinder
Worn internal seals
In air systems: faulty foot valve or leaking diaphragm

3. Stiff or Hard Pedal

Symptom: Very hard to press the pedal; little or no brake response.
Possible Causes:
Blocked or damaged brake lines
Seized pedal mechanism or pivot
Vacuum booster failure (in vacuum-assisted systems)
Faulty air brake valve (in air brake systems)

4. Grinding or Clicking Sounds

Symptom: You hear grinding, squeaking, or clicking when pressing the pedal.
Possible Causes:
Mechanical wear at the pedal hinge or pivot
Broken return spring
Debris or damage in the pedal assembly

5. Pedal Doesn’t Return Smoothly

Symptom: Pedal is slow to return or stays partially down.
Possible Causes:
Weak or broken return spring
Dirty or corroded pivot point
Internal binding or misalignment

6. Delayed Brake Response

Symptom: Pressing the pedal doesn’t immediately slow or stop the vehicle.
Possible Causes:
Worn or malfunctioning brake valve
Air or fluid leaks
Pedal assembly wear or misadjustment

7. Warning Lights or Error Codes

Symptom: Brake warning light, ABS fault, or system alert on the dash.
Possible Causes:
Faulty brake pedal position sensor
Electrical issue in brake-by-wire or ABS system
Failed electronic brake control module