Rennlist - Porsche Discussion Forums

Porsche 993: How to Replace Power Steering Fluid

Keep your steering system in top shape. Here's the easiest method for cleaning out the power steering system in your Porsche 993, and refreshing it with new fluid.

By Nik Romano - April 21, 2015

This article applies to the Porsche 993 (1993-1998).

While most manufacturers do not have a listed service interval for the power steering fluid, it is still a serviceable fluid that should be inspected and freshened up periodically. If the car is driven hard, the power steering will get a work out. Because the power steering fluid does not have a typical bleed valve or drain plug (like other fluids), the method of replacement is a bit unconventional, but it is quite easy and mess-free.

Materials Needed

  • Turkey baster
  • Hose (optional)
  • Pentosin CHF 202 fluid
  • Container for old fluid

Step 1 – Swap the fluid

Locate the power steering reservoir on the right side of the engine bay, near the fender. Have a look inside. You will probably notice the fluid is pretty black, and doesn't smell good. Considering the correct fluid is supposed to be green, there's likely some room for improvement.

Use the baster to suck out as much fluid as you can, and place it into a container to be recycled. If you attach a hose to the end of the baster, you will be able to get most of the fluid out. Refill the reservoir with fresh Pentosin to the correct level using the dipstick on the cap, and then put the cap back on.

Figure 1. The power steering reservoir is near the right rear fender.

Step 2 – Circulate

Using the baster will take out most of the fluid out, but you won't be able to get to the leftovers in the lines and the steering rack. To get the rest out, you will need to circulate the fluid. This will cause the old fluid to mix with the new, and then it can be fully removed.

Make sure the reservoir lid is on tight, and then fire up the car. With the car stationary, turn the wheels lock to lock several times to pump the fluid.

Figure 2. Turn the wheel lock to lock several times to circulate the fluid.

Step 3 – Rinse and repeat

Once you've circulated the fluid, you now have a combination of dirty and clean in the system. The next step is to repeat the process as many times as it takes for the fluid in the reservoir to remain clean, even after cycling. This procedure can take a while and a good amount of fluid. So if yours looks particularly dirty, you might want to purchase two bottles of Pentosin to be on the safe side.

Once you are satisfied with the cleanliness of the fluid, congrats because you are done.

Figure 3. Keep refreshing the fluid until it stays clean after circulating.

Some forum members have gone a step further by unbolting the power steering lines from the steering rack to completely flush the lines out. This method is slightly more thorough, and uses less fluid. But for most, the turkey baster method is more than adequate. The second method is included in the Related Discussions if you want to dive a little deeper.

Related Discussions