How and Why to do a Power Steering Flush | AG Auto

Nearly every car on the road nowadays is equipped with a power steering system. The primary role of this system is to make turning the steering wheel easier for the driver. You will immediately know when the power steering system has gone out in your vehicle because without it, turning the wheel will feel like you are in a tug of war contest with friction. The system greatly multiplies the force applied by the driver through the steering wheel to turn the front wheels, which also allows for smooth and quick turns- that’s why it’s also commonly referred to as “power assisted steering”. This extra help is generated with the help of either electric or hydraulic assistance.


This blog intends to cover all you need to know about the power steering system in your vehicle such as the basics of how the system works, how to know if your power steering system needs servicing, and how to check the power steering fluid yourself.


If you have any questions or concerns regarding the condition of your vehicle’s power steering system, call AG Automotive and schedule an appointment with our team of expert automotive technicians today!


There are 3 different types of power steering systems:


  • Hydraulic power steering (HPS)


As the name intends, this system is powered by hydraulic pressure that is powered by the steering pump to provide assistance to turning the steering wheel. The serpentine belt or accessory drive provides the sufficient pressure needed to move liquid within the hydraulic lines, called power steering fluid, to the power steering control valve located at the steering gear. A pressurized reservoir is in charge of maintaining and recycling power any steering fluid returning from the steering gear. 


As with many things under constant pressure, it is only a matter of time before problems start to develop- HPS systems are no exception. It is common for the HPS system to leak, make unnerving noises, and for the serpentine belt to break. HPS systems are great when they are working correctly, but they also have their own unique drawbacks; hydraulic pressurization draws horsepower from the engine, which leads to higher carbon emission output. Because of these drawbacks, automobile manufactures have begun to integrate a more environmentally conscious and reliable option for power steering systems in newer vehicles- the electric power steering system (EPS).


  • Fully electric power steering (EPS)


An electric power steering system (EPS) is very different from its hydraulic counterpart- the hydraulic power steering system (HPS). In an EPS system, the hydraulic pump is replaced by an electric motor and instead of hydraulics providing turning assistance to the driver, an electric power steering system creates the extra turning power. The electric motor is located on the steering column or steering rack and the steering dynamics are controlled by the vehicle’s onboard computer, called the ECU. 


EPS systems have become the preferred choice among automobile manufacturers as a way to incorporate power steering into vehicles because of their many advantages compared to the other two options available. An electric motor does not require additional horsepower from the engine in order to function, as required by HPS systems. In turn, EPS systems are able to provide better fuel economy and lower emissions. In addition to burning less fuel, EPS systems also eliminate the need of the environmentally hazardous hydraulic steering fluid, which might leak from the pressurized reservoir or hydraulic lines. Improper disposal of the fluid has also posed a great risk to the environment. Other benefits of an electric-powered system include guaranteed steering assistance for when the engine fails. It is also very easy to tune the steering dynamics via the ECU to adjust for a particular driving style or personal preference.   


  • Electric power hydraulic steering (EPHS)


An EPHS system is a hybrid of both the hydraulic and electric systems. Just like in EPS systems, there is an electric motor. The difference is that instead of replacing the hydraulic pump with an electric motor entirely, the electric motor provides the power to the hydraulic pump, replacing the need for the engine-driven serpentine belt. 


In this system, a hydraulic pump gets its energy from an electric motor instead of a belt driven by the engine. In EPHS the customary drive belts and pulleys that drive a power steering pump are replaced by a brushless motor. The power steering is driven by this electric motor, which reduces the amount of power that needs to be taken from the engine.


How to check the power steering fluid- DIY:


Note that electronically controlled power steering systems (EPS) do not use hydraulic fluid. This section will only be useful for vehicles that have a hydraulic power steering system (HPS) or the hybrid electric-hydraulic power steering system (EPHS). If you are unsure about which type of power steering system your vehicle has, you can locate that information in your owner’s manual provided to you by the vehicle manufacturer.


  1. Locate the power steering fluid reservoir
  2. Remove the dipstick & wipe off fluid with a cloth
  3. Put the dipstick back in and pull it back out
  4. Observe the fluid on the dipstick. It should be between the minimum & maximum fluid level markers
  5. Check to see if fluid smells burnt 
  6. You can refill the fluid up to the maximum line- be careful not to over fill. 
  7. Replace the cap


Note that refilling the power steering fluid reservoir does not resolve any leaks or contaminates within the system. It is okay to refill the fluid if the levels are low, but you should have your system inspected by an expert if you find yourself having to constantly add fluid more than once before flushes.


Warning signs of a failing power steering system:


We recommend that if you notice any of the symptoms that are associated with a failing power steering system, outlined below, you should schedule an appointment with our expert team of automotive technicians AG Automotive. It is important to be able to identify the warning signs and resolve any problems with your power steering system before they become worse. Hydraulic steering fluid has been determined to be environmentally hazardous. It is common for hydraulic systems to leak this fluid from the pressurized reservoir or hydraulic lines over time. 


  • hard to turn the steering wheel at low speeds or around sharp corners
  • The steering wheel doesn’t return to the center after a turn
  • Hear whining or squeaking while turning the steering wheel
  • A puddle or stain has formed under your car after it hasn’t moved for a long period of time


It is also recommended that you schedule a power steering fluid exchange service around every 50,000 miles to keep it clean of any debris or contamination.   


Schedule a power steering fluid exchange service with our expert mechanics at AG Automotive today!


If you have noticed that your steering wheel is harder to turn, hear whining or squeaking while turning, or notice that a stain has formed underneath your vehicle, Ag Automotive will have you back on the road in no time after we identify that your vehicle needs a power steering fluid exchange service. Our expert technicians have the tools and knowledge to replace your power steering fluid quickly and efficiently.


We want the job to be done right the first time, so we ensure your  power steering is working properly and exceeds the manufacturer’s specifications after our service is complete. We offer our customers a full service inspection and service of their power steering system so they can get back out on the road and drive with confidence knowing their vehicle was serviced by the best. 


We offer our customers a full-service power steering fluid exchange which includes:


  1. Inspect all hydraulic lines for leaks and condition
  2. Add BG power steering flush
  3. Cycle steering 10 times from stop to stop with front wheels off the ground and engine running
  4. Cycle brake pedal 10 times if vehicle equipped with hydro-boost braking system
  5. Power flush complete hydraulic system using flush machine
  6. Replace power steering filter (If applicable)
  7. Top off with new power steering fluid and bleed system 
  8. Cycle steering and brakes 10 times as before with front wheels off the ground
  9. Add power steering additive (If applicable)
  10. Clean and test drive
  11. Recheck fluid level and for leaks
  12. Quality Check
Don’t Second-Guess the Condition of Your Vehicle

Many auto owners struggle to know if the right work was done the right way on their car. As a courtesy, we provide digital vehicle inspections and photos so you can quickly and easily see what our experienced, professional technicians are seeing. Overall, we go the extra mile to help you make informed decisions on the repair and maintenance plan of your vehicle, so you can drive with confidence every time you get behind the wheel.