How to flush power steering fluid pump

There are multiple ways to "flush" your power steering fluid. Because fluid is circulating between the reservoir, pump, and steering rack, flushing all fluid is difficult. This method outlines a method allowing a single person to COMPLETELY flush ALL of the old fluid from the system while simultaneously replacing it with clean, new fluid.

Difficulty: Moderately Challenging

Instructions

Things You'll Need:

• Electric drill with multiple adapters to drive your power steering pump.
• Fluid line cap to cap the return port on the pump reservoir. I had a leftover cap from the packaging of a fuel filter that fit. You may also be able to use a small piece of rubber hose with a bolt plu
• Pipet, plastic syringe or similar to remove as much power steering fluid from reservoir as possible.
• Oil catch can for power steering fluid
• Various sockets and wrenches to reposition power steering pump if required.
• New power steering fluid (approx. 2 quarts was sufficient for mine. Check manual for capacity and then add one additional quart to purchase quantity)

1. 
    
   Combination of adapters to allow the electric drill to drive the pulley shaft.

   Identify what, if any, drive method you will be able to use to turn the power steering pump with a drill. I found using a common 1/4" drive bit extension, 1/4" hex bit to 1/4" square socket drive adapter, 1/4" socket, and a short hex allen bit (that I drove with a punch and hammer out of it's 3/8" "socket") fit the pump pulley center shaft.

2. 
    
   Safely support the pump in a method such as shown so that the drill can be positioned properly.

   Remove the pump drive belt. In order for this adapter combination to be utilized required unbolting the pump and repositioning. This is a 99 Saturn S-series. I imagine most transverse engine vehicles will be similar while north-south (RWD) vehicles may have adequate clearance to the front of the engine. This of course will vary depending on the vehicle and what drill/drive bits are required.

3. 
    
   Remove as much of the old fluid as possible and clean the cap and reservoir.

   To avoid as much of a mess when removing the fluid return line, first use a pipet or syringe to remove as much of the old fluid as possible from the reservoir. It is wise to clean the cap and reservoir top as much as possible at this point so as to avoid accidently contaminating the new fluid with falling dirt.

4. 
    
   Remove any clips/zip ties to allow unclamping the fluid return line. Notice that the return line feeds into the plastic reservoir while the feed line is a hard metal line coming from the pump body.

   Find and disconnect the fluid return line from the reservoir. It may be helpful to unclip both the feed and return line from the steering rack (if applicable) to give more slack in the lines making it a little easier to get some pliers or the like to disconnect the return line clamp. On my Saturn, the feed/return lines were zip tied right below the pump. This zip tie needed to be removed to allow the return line to be placed below the vehicle in an appropriate oil catch can.

5. 
    
   Cap the return port on the reservoir.

   This is where you will find out how well you did at removing the old fluid from the reservoir. The better the job you did before, the less mess now. Make sure no fluid drips on the pulleys below. Cap the reservoir port. I had a cap from the packaging for a fuel filter that fit. A small piece of hose with a bolt may work as well. This will not be under any pressure.

6. 
    
   Place the return line that was disconnected in a catch can below the vehicle.

   Place the return line that was disconnected in a catch can below the vehicle.

7. 
    
   Fill the reservoir with new fluid.

   Fill the reservoir with new fluid.

8. 
    
   With the driver door open, you can turn the steering wheel while watching how much fluid is coming out.

   Turn the steering wheel slowly lock to lock several times to get some of the old fluid out of the steering rack.

9. 
    
   Now use the drill to power the pump while maintaining a proper fluid level. (The reservoir cap does not need to be on)

   Now use the drill to power the pump while maintaining a proper fluid level. Use a slow speed.

10. 
     
    The fluid will become clear when the system has been properly flushed.

    Continue the process until the fluid coming from the return line appears clean.

11. Remove the cap and place a finger over the reservoir port as quickly as possible then remove your finger and put the return line back in place. This sounds messy, but actually, it was maybe 2-3 drips! Just be quick.

12. Clamp and bolt things back up, replace any cut zip ties and/or hose retaining clips, top of the fluid, turn the steering wheel a few times back and forth to purge any air out of the system and you are done.

Tips & Warnings

• Use a slow speed with the drill.
• Remove hose retaining clips to give more flexibility of pump position.
• Possibly use a 1/4" flexible drive adapter to eliminate the need to unbolt the pump?
• Buy enough power steering fluid to match the vehicles capacity (found in manual) plus 1 quart.
• I am assuming a certain amount of basic automotive knowledge here and have not included every possible detail.
• Each car is going to be unique. This article is primarily intended to show how the use of an electric drill can be used to simplify and improve this task.
• Be smart, wear safety glasses.