Most passenger cars, except some electric and hybrid models, have a hydraulic power steering system that allows the driver to turn the steering wheel without too much effort. The system consists of several elements: a rack and a pinion connected to the front wheels; a piston inside the rack and pinion, which moves thanks to the liquid under pressure which is pushed by the steering pump and thus helps to turn the wheels. Finally, there is a cylinder which contains liquid and which is mounted above the pump or away from it for easier access. When the liquid is insufficient, it becomes more difficult to turn the steering wheel and both the pump and the rack and pinion could be damaged due to the absence of the fluid that acts as a "shock absorber". For these reasons, it is important to check the power steering fluid regularly and top up when necessary.
Steps
Step 1. Look for the cylinder reservoir
If you are having trouble steering or hear a sharp noise coming from the steering wheel when you turn it, then there is a good chance that there is insufficient power steering fluid. You can find this fluid in the cylinder reservoir near the steering pump or further away from it. In this case, you will notice that there are pipes connecting the tank to the pump and there should be a label identifying the tank. The cylinder could be made of plastic or metal.
If you can't locate the cylinder, refer to the car's maintenance manual. Although the fuel tank is always mounted in the same place in most cars, in some models it may be located elsewhere for space saving reasons
Step 2. Check the liquid level
If the cylinder reservoir is constructed of clear plastic, you can see the fluid level inside. However, if it's metal or opaque plastic, then you'll need to insert a probe, which is typically attached to the cylinder cap itself.
- In some models, to obtain an accurate data, it is necessary to check the fluid level after running the engine for a short time. In other cases, you have to turn the steering wheel left and right several times while the engine idles.
- Some models, on the other hand, have a graduated probe or a scale engraved on the tank for measuring the level both "hot" (after starting the engine) and "cold" (after the engine has been switched off for a long time).. Other cars have notches for a "Minimum" and "Maximum" level in which the fluid must return. Remember to compare the fluid level with the correct scale.
Step 3. Check the length of the probe path covered by the steering fluid
If you are using a stick probe, you must first clean it of any traces of steering fluid as soon as you take it out of the cylinder reservoir. Next, you have to insert it back into its slot, all the way, and take it out once more.
Step 4. Check the color of the liquid
When in good condition, it must be transparent, amber or slightly pink.
- If the liquid is brown or black, then it has been contaminated with rubber fragments from the connecting hoses, gaskets or O-rings. In this case, take the car to the mechanic to verify the need to replace some elements of the steering system, in addition to the fluid.
- The liquid may appear darker than it actually is. If in doubt, look at the stain of this product on the rag or paper towel you used to clean the probe. If the stain is the right color, then the liquid has not been contaminated.
Step 5. Top up the liquid to bring the level back to the correct values
If your car's cylinder is graduated, then you can add fluid constantly, until it reaches the correct "hot" or "cold" level. If, on the other hand, you need to check the amount of liquid with the stick probe, add the liquid gradually, to avoid letting it overflow from the tank.
- Use only the type of power steering fluid recommended for your car model, as it must comply with well-defined viscosity parameters for the system.
- The automaker does not recommend using transmission fluid in the power steering system. There are too many different products, and if you use the wrong one, you could cause the power steering and its seals to malfunction.
- Be careful not to overfill the system with liquid. It is generally better to err on the side of things rather than go wrong. This is because the liquid expands due to the heat, thus reaching optimal levels. If you fill the tank to the brim and then try to start the car, the expansion of the fluid could cause problems and costly repairs.
Step 6. Put the cylinder cap back on
Depending on the type of car, you may need to screw or press the cap to put it back in place. Make sure it is closed securely before lowering the hood.
