In Mercedes 126 Repair: Forgotten Fluids, Part I we looked at the rear differential. Let's move on to another fluid that most homeowners never bother to change: power steering fluid.
CHANGING POWER STEERING FLUID
Most owners of the Mercedes 126 never dismantle their steering gear. But those who have a new appreciation of the importance of clean fluid in the power steering system. In addition to the entire worm gear and the interface between the ball nut and the sector gear that actually turns the Pitman arm, there is several sets of needle bearings. All these moving parts are lubricated by regular flows of power steering fluid. The more this fluid is highly contaminated, the more these parts will be used quickly. And a worn steering box results in sloppy steering, potential safety risks, and expensive repair or replacement. (The power steering pump, on the other hand, is much, much easier to replace, and the right units used can be purchased for as little as $ 50.)
There was a debate about the cleanliness of the aircraft. 39, use of the automatic transmission fluid in this system. While the ATF was specified in the owner's manual, the ATF was no longer what it was and becomes a little hostile to the many steering system seals. Ideally, the ATF should be avoided in favor of ordinary power steering fluid. While synthetic fluids are available, conventional fluids are perfectly fine.
To change the fluid, support the front of the car on the candles so that both front wheels are off the ground. Loosen the hose clamp securing the return hose to the "snorkel" back screwed into the pump, and point the hose into a suitable container to catch the old liquid. Plug the tuba or loosen it with a 19 mm wrench and turn it so that it points upwards, allowing you to fill the tank without losing the fluid from the return fitting. The standard procedure here is to start the engine and add liquid while the pump quickly forces the old fluid. But this procedure has major drawbacks. He is very categorical and not an operation of a single man. The flow rate is so fast that there is a big risk that the pump will run dry and suck in air unless there is a constant supply of new fluid. If things get out of hand, you need an assistant to turn off the engine immediately. If you do not have a wizard and do not want to risk damaging the pump or sucking air into the system, you need a better one. way.
Fortunately, it is perfectly possible to pump the old fluid into a highly controlled environment. simply by turning the steering wheel from stop to stop. Keep the fluid level in the tank above the filter to prevent air penetration, and continue until you are sure that the liquid leaving the system through the return pipe is clean. You need 2-3 pints to completely fill the liquid, but if you try to remove all the traces of ATF (red), you may find that it takes a little more to get a completely clean tank. When you are satisfied, reconnect the return hose and bleed the system completely by turning the steering wheel back and forth with the engine running.
This is, of course, the perfect opportunity to change the filter in the pump and inspect the rubber return hoses, replacement if necessary. The fact that Mercedes gave us a filter in the power steering pump tells us something about the importance of clean fluid. How many other automakers do that?