When you are replacing any power steering hydraulic component, it is critical to ensure that all the old fluid is flushed out of the system, as it may be contaminated. There are several ways you can do this, for example, some people use fluid exchangers, while others may just go with the buddy system method of flushing the system, which involves one person cranking the engine and turning the steering wheel while the other person replenishes the power steering reservoir.
Depending on the failure of the original unit, some technicians will perform a system flush using the old pump, then install the replacement pump and do a system flush one more time. This is okay, providing there has not been a catastrophic power steering component failure that has contaminated the system with metal or debris. Flushing is an important step which will ensure that contamination does not adversely affect your system.
Using the correct fluid that meets the Original Equipment manufacturer’s specifications is very important for proper performance and longevity of the replacement unit.
Here is the process for performing a simple but effective manual flush.
First, we want to disable the engine from starting. One way this can be done is by simply removing the fuel pump relay temporarily. Now, make sure the return line is disconnected from the PS pump. Then, cap the return pipe.
Ensure the front wheels are off the ground and supported by jack stands, or a lift if you have one. Ensure the reservoir is filled and hang the return line over a drain bucket.
While cranking the engine, cycle the steering wheel full left to full right. You will notice the old, dirty fluid is now pumping out of the return hose into the drain bucket (Be sure to not crank the engine more than 5 seconds at a time, as you don’t want to overwork the starter. You can do this in several steps with a short 5-10 second delay before cranking again.
Frequently check and fill the reservoir with fresh fluid, as you will be depleting the reservoir throughout this process.
Continue cycling left and right until all fluid runs clear out of the return hose. At this point, I recommend that you install a power steering filter on the return line as an added level of protection to ensure the system remains clean for many miles to come. These filters are directional, so pay attention to the arrow on the filter and make sure it aligns with the flow direction of the power steering fluid. In many cases, you will not need to cut the return hose to splice in the filter. You can simply install the filter to the end of your return hose and add a small piece of return hose to the other end, then reconnect to the pump.
Then, Attach the return hose, and ensure the fluid level is in the normal range. Re-Install the Fuel Pump Relay. Start and run the engine, cycling the steering wheel left and right. The pump should now be running quietly. Shut the engine off, re-check the fluid level, and top off as necessary
Now we’re going to show you the proper way to initially fill a power steering system.
Fill the reservoir to the cold line with an OE-approved power steering fluid and raise the front wheels off the ground (this is very important). With the Engine NOT running, slowly cycle the steering wheel lock to lock several times. You will notice the fluid level dropping in the reservoir. Replenish as necessary, and do NOT let the reservoir run dry.
Repeat these steps until the fluid level in the reservoir no longer drops (meaning the system is full). Now, start and idle the engine, and turn the steering wheel 180 degrees in both directions 5 times (DO NOT turn to lock). Turn the engine off and verify the fluid level. The fill procedure is complete, and in many cases, any unwanted air should be purged from the system. However, for some vehicles, an additional bleeding procedure is a MUST. Many power steering noise or performance complaints may not be caused by the actual component, but something else. Air trapped in the system is one of the most common causes of noise in power steering systems. Air causes cavitation in pumps, which in turn causes noise and eventually will damage the pump.
Here is an effective way to bleed air out of a power steering system using a hand vacuum pump and assorted adaptors, which will fit most reservoirs.
First, ensure the reservoir is filled to the FULL COLD level, and leave the cap off.
Then, raise the front wheels off the ground.
Next, using the appropriate adaptor, connected to a hand vacuum Pump – apply a vacuum, apply a vacuum of 20 inches of Mercury MAXIMUM.
Important: An assistant is needed for the next step.
Have an assistant slowly cycle the steering wheel lock to lock for at least two minutes as you maintain 20 inches of Mercury as needed using the hand vacuum pump.
Then, wait five minutes. Typically, vacuum drop is 2-3 inches of Mercury. Verify the fluid level. If the fluid level is low, fill to the full line.
Now, Reinstall the cap. Start and idle the engine. Then, turn the engine off and verify the fluid level. If the fluid level drops, add fluid. Repeat process until the fluid level stabilizes.
Start and idle the engine and turn the steering wheel 180° in both directions five times. DO NOT TURN TO LOCK.
Switch the ignition off. Verify the fluid level. Install the cap. The bleed procedure is complete. This video is sponsored by CARDONE.