Power steering
Senior Member
Joined: Aug 2004
Posts: 285
Likes: 0
From: Richmond, Va.
1991 300E
Just unscrew the power steering fluid resovior, take a turkey baster and suck the old fluid out, then unscwer the center post and bottom lid and replace the power steering fluid filter. The filters are cheap, and only need to be changed about every 30,000 miles but you might as well, it's very easy. I don't think you need to flush the system but you could always repeat the process a couple of times after driving around to get all the old fluid out. I don't think you need any special kind of power steering fluid. Check the owner's manual.
Super Member
Joined: May 2003
Posts: 696
Likes: 4
From: Motor City
95 E320 Cabriolet, 108K
If you decide to go with the flush method, here is the procedure I use. I've exchanged ps fluid on a few cars. You'll need a helper. The steps are rather simple.
1. Lift front tires off the ground.
2. Disconnect the ps return line, drain ps reservoir.
3. Plug open connection at the reservoir.
4. Secure the return line to a generously-sized container (at least one gallon). If needed, add a length of hose.
5. Fill reservoir.
6. Line up your bottles of new fluid for quick pouring.
Here comes the fun part...
7. Have helper turn car on, and immediately have him go through full range of steering motion (left and right) and shut off car, all the while you are trying to keep the reservoir filled.
8. Button everything back up.
9. Clean up mess.
10. Top off fluid.
The front tires must be off the ground so the system is unloaded, otherwise a lot of fluid is pumped out quickly with a lot of force. The return line must be secured to prevent a big mess. Keep at least a gallon of ps fluid on hand. The helper must know what they are doing.
I strongly recommend using power steering fluid rather than the Dexron stuff that is probably recommended for your vehicle. Modern Dexron formulations are different than the Dexron formulations present at the time when your car was built. Power steering fluid is the same as Dexron, but without the additives that may be harmful to the steering system.
1. Lift front tires off the ground.
2. Disconnect the ps return line, drain ps reservoir.
3. Plug open connection at the reservoir.
4. Secure the return line to a generously-sized container (at least one gallon). If needed, add a length of hose.
5. Fill reservoir.
6. Line up your bottles of new fluid for quick pouring.
Here comes the fun part...
7. Have helper turn car on, and immediately have him go through full range of steering motion (left and right) and shut off car, all the while you are trying to keep the reservoir filled.
8. Button everything back up.
9. Clean up mess.
10. Top off fluid.
The front tires must be off the ground so the system is unloaded, otherwise a lot of fluid is pumped out quickly with a lot of force. The return line must be secured to prevent a big mess. Keep at least a gallon of ps fluid on hand. The helper must know what they are doing.
I strongly recommend using power steering fluid rather than the Dexron stuff that is probably recommended for your vehicle. Modern Dexron formulations are different than the Dexron formulations present at the time when your car was built. Power steering fluid is the same as Dexron, but without the additives that may be harmful to the steering system.
