0107831 | Genuine Bendix® Air Brake Compressor TF-750 For Cat

An Air Brake Compressor 0107831 is the engine-driven pump that supplies compressed air for a truck or bus air brake system.

General Specifications

Specifications

Purpose & Function

1. Operates the air brakes (primary purpose)

• Supplies compressed air to:

  • Service brakes

  • Parking brakes

  • Emergency brakes

• Keeps air tanks charged so brakes apply and release correctly

Why it matters:
Without air pressure, the brakes cannot function—and the system is designed to apply brakes automatically for safety.

2. Maintains safe operating air pressure

• Continuously replaces air lost during braking

• Works with the governor to regulate pressure

• Keeps pressure in the safe range (usually 120–135 PSI)

Why it matters:
Consistent pressure = predictable braking performance.

3. Powers other air-operated systems

Beyond brakes, compressed air is used for:

• Air suspension

• Clutch assist

• Air horns

• Transmission controls

• Doors and accessories

Why it matters:
One compressor supports multiple critical vehicle systems.

4. Ensures fail-safe braking

• Air brake systems are fail-safe

• If pressure drops too low, spring brakes apply automatically

Why it matters:
Prevents runaway vehicles and loss of control.

5. Supports vehicle safety and compliance

• Required by law for heavy vehicles with air brakes

• Must meet DOT air-pressure build-up standards

Why it matters:
A properly functioning compressor keeps the vehicle legal and safe to operate.

Signs of a Bad Air Brake Compressor

1. Slow air pressure build-up

• Takes much longer than normal to reach operating PSI

• Fails DOT air build-up test
  Cause: Worn piston rings, leaking valves, internal wear

2. Won’t reach full pressure

• Pressure stalls below ~120 PSI

• Governor never cuts out
  Cause: Internal leakage or failing compressor head

3. Air pressure drops quickly

• Pressure falls fast after braking

• Low-air warning comes on often
  Cause: Compressor can’t keep up with demand

4. Excessive oil in air lines or air dryer

• Oily residue in tanks or dryer

• Oil blowing out of air dryer purge
  Cause: Worn compressor rings or seals (very common)

5. Unusual noises

• Knocking, rattling, grinding

• Loud ticking that wasn’t there before
  Cause: Mechanical wear or internal damage

6. Overheating

• Compressor runs extremely hot

• Burnt smell near compressor
  Cause: Restricted air flow, lubrication issues, overworking unit

7. Air dryer purging too often

• Dryer purges constantly or irregularly
  Cause: Compressor struggling to maintain pressure

8. Engine performance issues

• Loss of power

• Increased engine load
  Cause: Compressor seizing or dragging

9. Coolant or oil leaks (water-cooled compressors)

• Oil in coolant or coolant in oil

• External leaks at compressor
  Cause: Failed seals or cracked head

10. Brake warning lights / alarms

• Low-air buzzer sounds

• Brake warning light stays on
  Cause: Insufficient air pressure from compressor

About Bendix

Bendix is a leading manufacturer of air brake systems, safety technologies, and control components for commercial trucks, buses, and trailers. Known for innovations in braking, stability, and traction control, Bendix supplies OEM and aftermarket parts across North America. It is a subsidiary of Knorr-Bremse, a global leader in braking systems.