3943868 | Genuine Cummins® Exhaust Manifold For Cummins 5.9

• Dodge Ram trucks
  • Ram 2500
  • Ram 3500
    (with compatible 5.9L Cummins engine configurations)
• Medium-duty trucks
  • Freightliner
  • International
  • Blue Bird
  • Other commercial chassis using Cummins ISB engines
• Buses and shuttle buses
  • Vehicles equipped with Cummins ISB 5.9L engines
• Off-highway and industrial equipment
  • Construction equipment
  • Agricultural machinery
  • Industrial applications using Cummins QSB 5.9L engines

1. Air Brake Operation

• Provides the compressed air required to apply and release the brakes.
• Maintains safe operating pressure in the brake system.
• Essential for vehicle safety and legal operation.

2. Air Suspension Systems

• Supplies air to air-ride suspension components.
• Helps maintain ride height and improves ride comfort.
• Supports load leveling on commercial vehicles.

3. Pneumatic Accessories

The compressor can provide air for:

• Air horns
• Air-operated doors
• Pneumatic seats
• Clutch and transmission controls on some vehicles
• Other air-powered equipment

4. Maintaining System Pressure

• Continuously replenishes air lost during normal operation.
• Works with an air governor and air dryer.
• Automatically loads and unloads as system pressure changes.

Benefits of Using a TF-550

• Reliable air supply for critical systems.
• Durable design suitable for heavy-duty service.
• Helps reduce vehicle downtime.
• Supports safe braking performance.
• Commonly available replacement parts and service support.

1. Slow Air Pressure Build-Up

What you'll notice

• Air gauges take much longer than normal to reach operating pressure.
• The low-air warning stays on for an extended time after startup.

Possible cause

• Worn piston rings
• Leaking valves
• Internal compressor wear

2. Low Air Pressure

What you'll notice

• Air pressure never reaches the normal operating range.
• Frequent low-air pressure alarms.

Possible cause

• Compressor cannot produce enough airflow.
• Internal leakage or damaged components.

3. Excessive Oil in the Air System

What you'll notice

• Oil found in air tanks.
• Oil contamination in the air dryer.
• Oily discharge when draining air tanks.

Possible cause

• Worn piston rings or seals allowing engine oil to pass into the compressed-air system.

4. Compressor Runs Continuously

What you'll notice

• Compressor rarely unloads.
• Engine may seem to work harder than usual.

Possible cause

• Compressor is struggling to maintain pressure.
• Internal wear reducing efficiency.

5. Unusual Noises

What you'll notice

• Knocking
• Grinding
• Squealing
• Rattling sounds from the compressor area

Possible cause

• Worn bearings
• Damaged pistons
• Internal mechanical failure

6. Air Dryer Purges Excessively

What you'll notice

• Frequent air dryer cycling.
• Irregular pressure fluctuations.

Possible cause

• Compressor output problems or air system issues.

7. Overheating

What you'll notice

• Compressor becomes excessively hot.
• Burnt smell near the compressor.

Possible cause

• Restricted cooling passages
• Poor lubrication
• Excessive duty cycle

8. Air Leaks from Compressor Area

What you'll notice

• Hissing sounds around the compressor.
• Visible leaks at fittings or gaskets.

Possible cause

• Failed gaskets
• Loose fittings
• Cracked components

9. Excessive Moisture in Air Tanks

What you'll notice

• More water than usual when draining tanks.
• Reduced air dryer effectiveness.

Possible cause

• Compressor overheating or reduced efficiency.