KNX13060 | Genuine Bendix® Tu Flo® 550 Air Brake Compressor

1. Generate Compressed Air

The compressor takes in outside air and compresses it so it can be stored in the vehicle’s air tanks.

2. Maintain Proper Air Pressure

It keeps the air system at the correct pressure level (usually 90–120 psi) so the brakes always have enough power to operate.

3. Power the Brake Chambers

The compressed air is used to push the brake chamber diaphragms, applying the brakes when the driver presses the pedal.

4. Supply Air to Auxiliary Systems

Besides brakes, it also provides air for:

• Air suspension

• Air horns

• Air-powered transmissions or accessories

5. Ensure Safe Braking in Heavy-Duty Vehicles

Large vehicles need a stronger, more reliable braking system than hydraulic brakes can provide.
Compressed air makes this possible.

1. Slow Air Pressure Build-Up

• Takes too long for tanks to reach operating pressure

• Low-air warning stays on longer than normal

• Vehicle struggles to reach 90–120 PSI

This is one of the biggest indicators of compressor trouble.

2. Weak or Inconsistent Air Pressure

• Pressure drops too quickly

• Air gauges fluctuate

• Brakes feel weak or delayed

Often caused by worn internal parts or poor compression.

3. Unusual Noises From the Compressor

• Knocking

• Grinding

• Rattling

• Screeching

These noises suggest internal wear, loose parts, or bearing failure.

4. Compressor Running Constantly

• Compressor never unloads

• Keeps pumping air non-stop
  This may happen due to:

• Internal wear

• Air leaks elsewhere

• Bad air governor

A healthy compressor cycles on and off.

5. Oil in the Air System

• Oil found in air tanks

• Air dryer saturated with oil

• Oily residue in valves or brake components

This means the compressor’s piston rings or seals are worn.

6. Excessive Heat

• Compressor gets unusually hot

• Premature air dryer failure

• Hot airline coming off compressor

Overheating can damage seals and reduce performance.

7. Low-Air Warning or Brake Light

• Dash warning comes on frequently

• System can’t maintain safe pressure levels

This is a major safety concern.

8. Reduced Braking Performance

• Longer stopping distance

• Spongy or delayed brake response

• Emergency spring brakes may begin applying

This usually happens when air pressure can’t stay above required limits.