Power Steering Pump Noise

International ProStar and LT Series Power Steering Pump

Posted by author-avatar

The ProStar and LT series have specific pump requirements for Cummins and Navistar engines. Learn the OE numbers.

What the Driver Feels

  1. Whine at idle on a ProStar
  2. Heavy steering on a loaded LT
  3. Leaks at the pump gasket
  4. Pressure below spec
  5. Contaminated fluid
  6. Pump noise after service
  7. Groan at full lock
  8. Belt slip on cold mornings

What Causes It

The International ProStar (2008-2016) with the Cummins ISX15 uses pump 3624643C91. The newer International LT (2017+) uses updated pumps for the Cummins X15. The ProStar was known for cab aerodynamics, but the power steering system is conventional.

The International 4700/4900 medium-duty trucks with the DT466E use pump 2005337C91. These are work trucks that see constant stop-and-go use, wearing the pump faster than over-the-road trucks.

How to Inspect

Safety: International trucks have tilt cabs — use the cab latch and safety arm.

1. Identify your engine (Cummins ISX vs Navistar DT).

2. Test pressure per International spec.

3. Inspect the pump mounting and belt.

4. Check the reservoir filter.

5. OE cross: 3624643C91 (ProStar ISX), 2005337C91 (DT466E).

Recommended Repair

  1. Replace with OE-equivalent pump.
  2. Flush the system and replace the return filter.
  3. Use International-approved hydraulic fluid.
  4. Replace the high-pressure hose at the same service.
  5. Bleed and pressure-test.

Send us your VIN or OE number to get a fast wholesale quote on a replacement power steering pump. We stock new and reman pumps for passenger cars and heavy-duty trucks.