Power Steering Fluid Flush

This procedure drains and replaces the power steering fluid in the hydraulic steering system to maintain proper lubrication and remove contaminants.

Warnings

Tools required

Fluids

• Mopar ATF+4 — 2.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Allow engine and power steering system to cool completely
4. Locate power steering fluid reservoir on driver side of engine bay
5. Verify you have sufficient Mopar ATF+4 fluid (2.5 quarts minimum)

Procedure

1. 1

   Remove old fluid from reservoir
   Open the power steering reservoir cap. Use a turkey baster or fluid transfer pump to remove as much old fluid as possible from the reservoir. Transfer the old fluid to a drain pan. Continue extracting until the reservoir is as empty as possible.
2. 2

   Fill reservoir with fresh fluid
   Using a funnel, fill the power steering reservoir with the manufacturer-specified fluid (verify on reservoir cap or owner's manual — typically Mopar power steering fluid for the Cummins application) to the appropriate COLD/MIN level mark. Do not overfill. Do not overfill. Replace the reservoir cap loosely.
3. 3

   Raise front of vehicle
   Raise the front of the vehicle using a jack and secure it on jack stands under the frame rails. Both front wheels should be off the ground to allow free turning of the steering system. Ensure the vehicle is stable before proceeding.
4. 4

   Cycle steering system (first pass)
   With the engine OFF, turn the steering wheel slowly from full left to full right lock approximately 10 times. This circulates the new fluid through the system and pushes old fluid back to the reservoir. Check the reservoir fluid level and top off as needed between cycles.
5. 5

   Extract contaminated fluid
   Remove the reservoir cap and use the turkey baster or pump to extract the fluid again. The fluid will now be darker as old fluid has mixed with the new. Remove as much as possible and refill with the manufacturer-specified power steering fluid to the appropriate COLD/MIN level mark.
6. 6

   Cycle steering system (second pass)
   With the engine still OFF, turn the steering wheel slowly from lock to lock another 10 times. Monitor the reservoir and add fluid as needed. The fluid should begin to look cleaner with each cycle.
7. 7

   Final fluid exchange
   Extract fluid from the reservoir one final time and refill with fresh Mopar ATF+4. For heavily contaminated systems, repeat steps 5-7 until the extracted fluid remains clean and matches the color of the fresh specified fluid. Fill to the FULL COLD mark.
8. 8

   Lower vehicle and start engine
   Lower the vehicle from jack stands back to the ground. Remove jack stands and lower jack completely. Start the engine and let it idle. Check the reservoir fluid level as the system pressurizes and add fluid if needed to reach the FULL HOT mark.
9. 9

   Purge air from system
   With the engine running at idle, slowly turn the steering wheel from lock to lock 5-10 times. Do not hold the wheel at full lock for more than 2-3 seconds to avoid overheating the pump. Listen for any whining or groaning noises that indicate air in the system. Continue cycling until steering is smooth and quiet.
10. 10

    Final fluid level check
    With the engine running and at operating temperature, check the fluid level one final time. Top off to the FULL HOT mark if needed. Install the reservoir cap securely. Check for any leaks around the pump, hoses, and steering gear.

Reassembly

1. Ensure reservoir cap is installed securely
2. Wipe down any spilled fluid from engine bay and components
3. Dispose of old power steering fluid according to local regulations

Verification

• Start engine and verify power steering operates smoothly without noise or whining
• Turn steering wheel through full range of motion and confirm no binding or unusual sounds
• Check fluid level is at FULL HOT mark with engine running and at operating temperature
• Inspect all power steering connections for leaks
• Test drive vehicle and verify normal steering assist function at various speeds

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