Flushing the Power Steering
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After recieving several questions on Autofix.com.au regarding this issue, today we are going to look at the best way to flush your power steering system. There are several different ways to do this and I believe the way I am going to show you is the only way to completely flush the system of old fluid. Once again please read and understand all the steps outlined before starting the job.
The first thing you need to remember is that the front wheels of the car MUST be off the ground to do this, damage will be done to the pump and steering rack if this is not done.
The second requirement is that you know which hose is the return hose to the pump or reservoir and
which hose is the high pressure from the pump. Generally the return hose will be all rubber with hose clamps at either end and the high pressure hose may contain a length of steel pipe with crimped-on fittings at either end. It may also be all rubber, but with the same crimped-on fittings. Another way to tell is by the size of the fittings on to the steering rack itself, the high pressure hose allways has larger fittings than the low pressure return hose. The vehicle we are doing this job on is a VT Commodore and has two rubber hoses connected to the reservoir, the larger of the two is the pump feed and the other comes from a small cooller fitted at the front of the vehicle. Our return hose in this instance is the smaller of the two.
Once you
have a grip on which hose is which it’s time to jack the car up so both front wheels are off the ground, place a catch-tray underneath the car and remove the return hose from the pump/reservoir. The next step requires a very technical piece of equipment, a small length of hose with a bolt stuck in the end of it! Yeah I know it’s crude but it’s very effective believe me! The idea is to place the small piece of hose over the outlet where you removed the return hose from effectively sealing the pump/reservoir again.
Next we take the return hose and place the loose end into the catch-tray under the car. You may need a piece of hose to make an extension for the return hose so it reaches the catch-tray.
The next step requires two people. One to start the car and move the steering wheel from lock to lock and the other to keep fluid in the reservoir. The fluid level drops very quickly and to avoid damaging the pump or rack, the fluid needs to be kept up to it. Two to three complete turns is all that is needed to flush it completely. Switch the car off as soon as you have finished turning the steering wheel.
The final step is to remove the blocking-off hose, refit the return hose to the pump/reservoir, top up the fluid level and once again start the car and move the steering wheel from lock to lock, ensuring that there is sufficient fluid in the pump/reservoir to prevent any damage being done. Don’t be surprised to hear some whining or gurgling sounds coming from the pump, it takes a while to rid the system of all the air present. I once had a car that took a day of off and on driving to expel all of the air! I wasn’t happy because I thought my apprentice hadn’t been careful enough with keeping the fluid level topped up even though he swore black and blue that he did. Once everything is operating normally and the fluid level has been checked, time to jack the car down and take it for a drive. I normally check the fluid level again after the car has been sitting for a few hours, just to be sure.
And that’s about it for flushing your power steering. If you do this as per your manufacturers handbook the system should give you years of problem-free steering!
Take care and be safe on the roads.
Craig
