When should I Change Or Flush The Power Steering Fluid In My Subaru?
When should I change or flush my Power Steering in my Subaru?
One fluid that often goes neglected in a Subaru is the Power steering fluid, other than calling out the occasional inspection Subaru doesn’t really specify any real service interval and as such we have over the last few years dealt with more and more power steering fluid related symptoms.
The design of the 2000 and newer models creates a situation where old fluid can create power steering symptoms as well as take a toll on seals and internal components as well. The fluid in the Power steering system is a hydraulic type fluid and in many applications automatic transmission fluid such as Dextron III is used. There is not a drain plug for the fluid, the systems typically don’t have any type of filtering device and the fluid actually can become dirty pretty quickly. The best way to deal with this is to flush out the fluid; at our shop we use a power steering flush machine with a flushing agent and some fluid conditioner when needed and offer to change out the fluid in the reservoir during a 30/60/90k service included if that’s al that is needed. At home you can use a turkey baster to remove the fluid in the reservoir but you will have to do this, then re fill several times before you have even remotely clean fluid.
The newer model Subaru vehicles can suffer from old fluid over time taking a toll on the return line o-ring which can create a small air leak causing the fluid to become aerated, this will typically start out as a cold engine only symptom gradually becoming worse and if not dealt with can eventually damage the power steering pump.
We have simply replaced the fluid on many H6 models from 2001 to 2004 to eliminate a cold engine growl or whine type noise being emitted from the power steering pump. The 2000 to 2009 4 cylinder models can have an o-ring that will no longer seal when cold as a result of the fluid causing it to shrink over time and no longer seal until the o-ring warms up and expands into the sealing body of the power steering pump.
It has been a common repair for many years to reseal the power steering pump do to external fluid leaks (typically after many miles). On the 2000 and newer models we have observed less external leaks but more actual symptoms however, which at a minimum require you to replace the return line o-ring and perform a flush if there is a power steering type noise as a result of fluid aeration.
I would like to point out that a loose or worn power steering belt can cause noise and symptoms as well, please don’t automatically assume that after reading this article that you need to reseal your power steering pump
If you are a local customer and would like to schedule a power steering system flush you can do so below.
If you are somewhere else in the country or the globe for that matter and have a power steering type noise there isn’t much we can do for you over the phone that we haven’t already tried to address on the website under two separate articles this one and the other is here Power steering problems Explained.
I Hope this helps!
Justin
All Wheel Drive Auto
I have a 2004 Subaru Forester with 105,000 miles. From a cold start, steering right or left is very hard and bumps. After the initial couple of turns it is then okay until car has sat and gotten cold again. There is no noise associated with the problem. My mechanic, who has not felt the problem, changed the power steering fluid and checked the system but reports they couldn’t find any problem in the system. However, the problem continues and appears to be lasting longer after a cold start. Any suggestions? I am in Jacksonville, FL, so coming in is not an option. Any direction you can provide will be very much appreciated.
Hi Robert,
Sounds like a weak pump, but the seals internal in the rack could be swollen as well.
The most common is the pump, there is no port to check pressure and gauge against specs I am afraid so this is a Experience type of a call for a Technician some may be uncomfortable doing this. I know that even here if we run into something we cant “prove” we will only make a suggestion to a customer and hope for the best, its not an exact science, as the market place wont bear the costs.
Justin
Hi Justin,
Thank you for your reply. Something new has just occurred which may or may not affect your response. This morning, with temps at 31 degrees, as I experienced the ‘bumps’ while turning the stearing wheel, the ‘brake’ and ‘battery’ lights on the dash flashed on and off at each ‘bump’ of the wheel. Any possible correlation? Thanks again for your help.
Problem turned out to be a bad belt (slipping). Replaced the engine belt and the problem went away.
The brake and battery light make my think something with a main battery connection such as the positive or negative battery cables being losse at either the battery or engine.
Id start with inspecting those items
Hope that helps
Justin
Hi Justin,
I have frequently visited your website for repair clues with my 2001 subaru legacy wagon. Often I have found valuable suggestions. This time I have a power steering question. fluid is leaking out as soon as it is put in and I have lost steering power. I had the rack replaced about 8 months ago, the fluid appears to be leaking from one of the two lines leading to the rack. Any ideas or comments are appreciated. Unfortunately, I’m in Virginia and not near your facility.
In your part of the country it is common for the hydraulic lines to corrode over time and leak where the rubber hose is crimped fit to the steel line.
Thank you for the detailed yet simple explanation. It was spot on with the troubles I was experiencing.