The steering system of modern passenger cars is equipped with a hydraulic booster - a device due to which rotation of the steering wheel does not require physical effort from the driver. Despite the statements of many automakers that the power steering fluid must be replaced only if the device is repaired, the condition of the system should be closely monitored and contaminated technical fluid should be changed as necessary.
- 2 How to choose oil for power steering
2.1 Types of fluids for popular cars: table
- 5.1 Tools for work
In what cases is replacement required?
The power steering fluid performs several functions:
- it is the working fluid of the system,
- ensures its safe operation,
- protects device elements from overheating,
- corrosion and other damage,
- reduces wear on steering system parts.
The specially developed substance is designed to function in a wide temperature range - from –40 to +120°C.
Diagram of power steering on cars of the VAG concern (Volkswagen Aktiengesellschaft)
There are two key situations when it needs to be replaced:
- During repair of the power steering or after removing and installing the steering rack, the power steering fluid becomes contaminated with mechanical particles that can damage the system and cause a rapid loss of the fluid’s performance properties. In this case, it is necessary to completely replace the power steering fluid, even if the oil is relatively fresh.
- After a mileage of 20,000 km, it is recommended to regularly check the condition of the technical fluid in the power steering expansion tank. Using a probe, a small amount of the substance is placed on a clean, light surface - a napkin or paper. If the liquid is clear and retains its original color (red, green or yellow), then replacement is not necessary. The reasons for changing the fluid are mechanical contamination, cloudiness, and a burnt smell.
If the car's mileage does not exceed 20,000 km per year, replacing the power steering fluid is necessary approximately every two to three years. If this is not done in a timely manner, the contaminated synthetic substance loses its operational properties, which leads to overheating and damage to system elements, failure of the power steering, pump, and steering rack.
Recommendations from experts
Experienced motorists and car service employees recommend changing the grease in the power steering with an assistant. This is due to the fact that while one person is turning the steering wheel, the other is holding the hose with a funnel and monitoring the situation. This prevents the hose from flying out of the container. Also, when topping up, it is advisable to have someone control the volume of motor oil in the unit.
In car services, lubricant is changed by qualified specialists who thoroughly wash the unit with special liquids that are not always available to ordinary people. At the end of the procedure, service workers carry out a high-quality pumping and check of the power steering.
The disadvantage of contacting a specialized service center is the financial cost. However, changing the petroleum product in the power steering is not too expensive; any driver can afford such a service. It is better to spend money on car service services right away than to face the need to repair your car in the future due to errors during the replacement procedure.
03/11/2019 Author: Master Service 641
Power steering is a reliable assistant and faithful friend of the driver. It makes it easier to turn the steering wheel, making driving smooth and comfortable. But in order for the power steering to serve you faithfully for as long as possible, it also needs to be taken care of.
Steering rack diagram with power steering
What is power steering oil
It is the oil in the power steering that essentially helps the steering wheel rotate, transmitting force from the steering wheel to the wheels due to the pressure in the system. In addition to its main function, power steering oil serves as a lubricant for the entire steering rack mechanism, cools it and carefully protects it from corrosion.
What types of oils are there and what myths the auto community has come up with about it, read here.
According to the rules, scheduled oil changes are carried out once every one or two years, depending on the load on the car, or at least once every 100 thousand kilometers. An urgent or emergency replacement is carried out if a pump or other element of the hydraulic system fails.
What does a power steering filter look like?
But our drivers usually “forget” and don’t change the oil for 3-4 years. What does this mean?
- A huge amount of tiny debris, metal shavings and other wear products accumulate in used oil. All this suspension does not benefit the hydraulic system, especially the filter, which is located in the power steering reservoir. It becomes clogged and the pump is overloaded. The result is a broken power steering pump, the price of which, by the way, is not the lowest.
- Power steering oil is not as hygroscopic as brake fluid, but it also absorbs condensation. Water in the power steering system causes inexorable and merciless corrosion of the steering rack.
- In addition, condensation in the oil contributes to the viscosity of the oil in winter. The oil cannot circulate normally, there is an excessive load on the entire unit and its seals, the system depressurizes, leaks, and a hum appears under the hood.
- And in hot weather, oil with condensation, on the contrary, is excessively liquid, “watery”. In this case, such oil does not create the necessary pressure on the wheels. The steering wheel becomes tight or turns jerkily.
How to choose power steering oil
The hydraulic system uses a synthetic substance that must meet the following parameters:
- maximum operating temperature from 110°C;
- stable viscosity of the medium regardless of temperature and load level;
- the presence of additives to improve the efficiency of functioning under pressure;
- resistance to foaming;
- safety for the materials from which seals and hoses are made.
The choice of liquid is carried out in strict accordance with the manufacturer’s requirements
Today, manufacturers offer power steering fluids that vary:
- by type of base (synthetic and mineral);
- by viscosity;
- according to the characteristics of additives;
- by performance properties, etc.
On sale you can find power steering fluid in red, yellow and green colors, and red and green compositions are mineral and synthetic, and:
- red - only for cars with automatic transmission;
- yellow - universal, for “mechanics” and “automatic”;
- green - only for cars with manual transmission.
Important! Synthetic and mineral oils should absolutely not be mixed, even if they have the same color! Using two types of oil at the same time results in the formation of clots, blockage of the pump and holes in the steering rack, and system breakdown.
When choosing power steering fluid, you should follow the recommendations of the car manufacturer and use the same composition that is poured into the system, or its equivalent.
It often happens that liquids need to be purchased as a kit. One bottle flushes the system, the second remains in the power steering
Synthetic compounds may only be poured into the system for which they are specified by the vehicle manufacturer. The use of synthetics instead of mineral oil will lead to damage to the sealing elements and hoses, as a result of which the hydraulic booster will lose its seal and fail. Even pre-flushing the system will not get rid of this problem.
Types of fluids for popular cars: table
| Red (mineral or synthetic) | Dexron II | Daewoo Nexia, Passat until 2005. |
| Dexron III | Toyota Avensis, Camry, Patrol, Corolla until 1997; BMW until 1994; Korean Chevrolet Lacetti and Cruz | |
| Dexron IV | Chevrolet Aveo after 2012. | |
| New PSF-3 | Korean cars, including KIA, Hyundai | |
| Yellow | Mercedes, some other cars | |
| Green (synthetic or mineral) | VAG cars; French cars with the exception of Renault Duster, Logan, Sandero | |
It is allowed to mix power steering fluids from different manufacturers with each other if they match in type (mineral with mineral, synthetic with synthetic), color and characteristics.
Operating principle of the steering gear
The VAZ 2107 is equipped with a worm-type steering gear. The principle of its operation is as follows.
The driver turns the steering wheel. The worm shaft is driven by cardan joints. It rotates, moving the double-ridge roller. Then the secondary shaft rotates, on which the bipod is fixed, driving the steering rods.
The trapezoid moves the steering knuckles, turning the wheels in the desired direction.
To reduce friction of the internal elements of the steering gear, transmission oil with a viscosity grade of SAE 75W-90, 80W-90 or 85W-90 is poured into the mechanism. The filling volume of the VAZ 2107 gearbox is 0.215 liters.
DIY partial replacement
A simplified replacement option is allowed only if the car owner knows exactly what type of composition is currently poured into the power steering reservoir and has the opportunity to use the appropriate composition. The reason for a partial replacement is contamination of the tank, stains or suspension on the surface of the fluid after a long period of non-use of the car.
Procedure:
- Unscrew the cap of the power steering reservoir, and using a 20-cc syringe + elastic tube, pump out the contaminated oil.
- Fill in new fluid, focusing on the upper mark, and put the plug in place.
It's better to pour through a straw than to splash precious liquid past
- Start the engine, turn the steering wheel right and left several times until it stops.
- Stop the engine and use a dipstick and white paper to check the level and condition of the fluid in the power steering reservoir.
- If necessary, repeat the procedure - the oil should eventually become clean.
How much fluid to pour into the power steering when completely filled?
Before proceeding with a complete replacement, you should find out not only the type of fluid, but also the required volume. If you did not find the information in the car manual, you can use an Internet search.
Eg:
- Toyota RAV4 D4D requires DEXRON II-D or DEXRON III fluid in a volume of 1.1 liters.
- for Renault Logan, Elf Elfmatic G3 fluid is used in a volume of 1 liter;
- Ford Focus 2 requires green liquid Ford WSA/M2C195/A or analogues, including Ravenol-PSF in a volume of 2 liters.
How to completely replace a Ford Focus 2
A complete replacement will be considered using the example of the Ford Focus II.
Tools for work
To completely replace the fluid in the power steering, for example, Ford Focus 2, you will need to use:
- a hose at least 1.5 meters long with a fitting at the end, its diameter must correspond to the return hose of the system;
- a hose of similar diameter about a meter long, equipped with a plug;
- containers with a volume of several liters and with wide edges or neck;
- pliers with curved tips;
You can use regular pliers, but they are less convenient
- jack;
- new power steering fluid (with a reserve, since flushing of the system is provided).
How to change: instructions
It is recommended that two people perform this type of maintenance.
- Raise the car with a jack to make it easier to turn the steering wheel. The engine must be turned off.
- Unscrew the fasteners and remove the power steering reservoir.
Using pliers, move aside the clamp that secures the return hose (it comes from the steering rack). Drain the old fluid from the return hose into a substitute container. Install a hose with a fitting instead of the return line. Instead of the second hose (direct supply), install a hose with a plug. Hose location - Then fill the reservoir with new fluid in a thin stream.
One person should turn the steering wheel all the way in both directions, the second should monitor the quality of the discharged waste. Clean oil differs from contaminated oil in color and smell. Rotate the steering wheel left and right until it stops several times - After you are sure that the power steering is clean, install the standard hoses in place, secure the reservoir, and add new fluid to the top mark. To remove air locks, start the engine and smoothly rotate the steering wheel all the way in both directions - two or three repetitions are enough for the fluid to fill the entire system. Using the dipstick, check the fluid level and add if necessary.
- If the replacement is carried out correctly, the steering wheel will rotate smoothly and effortlessly. Once you are sure of this, screw in the cap of the power steering reservoir. Check the tightness of the hose connections.
Differences between hydraulic fluids
Dexron. Lubricants have been produced since 1968. This is a separate class created by General Motors Corporation. Dexron is an official brand and is not manufactured exclusively by GM.
ATF (Automatic Transmission Fluid) - lubricants intended for automatic transmissions. Widespread among Japanese manufacturers. Often such hydraulic oil is found in power steering, most of it has a red tint.
PSF (Power Steering Fluid) – oil for hydraulic booster.
Multi HF are universal hydraulic oils for use in hydraulic power steering systems, allow complete mixing and interchangeability, and have approvals from many automakers. This oil is the best choice when purchasing.
