Power Steering Fluid Flush

This procedure flushes the power steering system to remove contaminated fluid and replace it with fresh ATF+4, ensuring proper steering operation and extending component life.

Warnings

Tools required

Fluids

• ATF+4 — 2.5 qt

Preparation

1. Park vehicle on level surface and set parking brake
2. Place wheel chocks behind rear wheels
3. Allow engine to cool if recently driven
4. Locate power steering fluid reservoir on driver side of engine compartment near firewall
5. Have drain pan and fresh ATF+4 fluid ready

Procedure

1. 1

   Remove old fluid from reservoir
   Remove 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 the drain pan. Continue until the reservoir is as empty as practical, typically leaving only residual fluid at the bottom.
2. 2

   Fill reservoir with fresh fluid
   Pour fresh power steering fluid meeting the manufacturer's specification (verify against the reservoir cap and owner's manual — many 2007 Cummins trucks specify a dedicated PS fluid rather than ATF+4) into the reservoir until it reaches the correct COLD level indication. This typically requires approximately 0.5-0.75 quarts initially.
3. 3

   Raise front of vehicle
   Safely raise the front of the vehicle using a jack and support it securely on jack stands. This allows the front wheels to turn freely without load, making the flushing process easier and safer. Ensure the vehicle is stable before proceeding.
4. 4

   Cycle steering lock to lock
   Start the engine and allow it to idle. Turn the steering wheel slowly from full left lock to full right lock 3-4 times. Do not hold the wheel at full lock for more than 2-3 seconds. This circulates the new fluid through the system and begins displacing old fluid.
5. 5

   Check and top off fluid
   Turn off the engine and check the fluid level in the reservoir. The level will have dropped as fluid circulates through the system. Top off the reservoir to the FULL COLD mark with fresh ATF+4. Inspect the fluid color; it will likely appear darker as old fluid mixes with new.
6. 6

   Repeat cycling process
   Start the engine again and repeat the lock-to-lock steering cycle 3-4 more times. Turn off the engine and check fluid level again, topping off as necessary. The fluid should begin appearing cleaner and more red in color.
7. 7

   Perform final flush cycles
   Continue the process of cycling the steering lock-to-lock, checking fluid level, and topping off until the fluid in the reservoir remains clean red ATF+4 color with no darkening after cycling. This typically requires 3-5 total cycles, using approximately 2-2.5 quarts total of fresh fluid.
8. 8

   Check for leaks and proper operation
   With the engine running and wheels still off the ground, inspect all power steering hoses, connections, and the steering gearbox for any signs of leaks. Verify smooth steering operation with no unusual noises. Turn off the engine.
9. 9

   Lower vehicle and final check
   Lower the vehicle from the jack stands and remove the jack. With the engine running and wheels on the ground, turn the steering wheel lock-to-lock 2-3 times at idle. Check the fluid level one final time with the engine running and wheels straight ahead; the level should be at the FULL HOT mark. Top off if needed and reinstall the reservoir cap securely.

Reassembly

1. Ensure power steering reservoir cap is tightened securely
2. Wipe down any ATF+4 spills from engine compartment and painted surfaces
3. Properly dispose of used power steering fluid at a recycling center or automotive shop

Verification

• Start engine and verify smooth, quiet steering operation with no whining or groaning noises
• Turn steering wheel lock-to-lock and confirm no binding or unusual resistance
• Check power steering fluid level is at FULL HOT mark with engine at operating temperature
• Inspect all power steering components for leaks after test drive
• Verify fluid color remains clean red ATF+4 appearance
• Recheck fluid level after 50-100 miles of driving and top off if necessary

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