All About Power Steering Fluid

Thanks to power steering, we get to control and move the vehicle the way we like without any effort. However, such mechanical devices need a sort of fuel to keep up the good work. And that’s when the steering fluid comes into effect.  

What is power steering fluid? Power steering fluid is a medium that makes sure the wheels turn easily and that the components like valves, pistons, pumps, and hoses work well. It gives power to the steering system and keeps the parts lubricated. These are what power steering fluids do. 

Now through this article you are gonna learn all bout power steering fluid. Let’s get started.

Contents Of Power Steering Fluid

Power steering fluid is a kind of hydraulic fluid containing 92wt% of mineral oil, silicones, or synthetic oil and a variety of additives. It also has 0.5-5wt% of vegetable-based oil, particularly an estolide of a hydroxy-stearic acid. When it comes to additives of power steering fluid, it includes- 

1. Anticorrosion agents like amines, alkenyl succinic esters, and alkenyl succinic imides. They work to make the fluid non-corrosive. 
2. Antioxidants like phenols (i.e. mono-alkyl and poly-alkyl phenols) and amines. They prevent auto-oxidation of fats and oils. 
3. Anti-wear additives like phosphate esters. They prevent asperities and abrasion in the fluid system. 
4. Friction-controlling additives like organic molybdenum compounds and fatty acid compounds. They help decrease friction. 
5. Antifoaming agents like esters and silicone compounds. They help hinder the creation of foam. 
6. Viscosity index improvers like methacrylate copolymers and olefin copolymers. They resist the dilution of power steering fluid at extreme temperatures. 
7. Detergents like alkaline earth metal phenates and alkaline earth metal sulfonate. They prevent formation and buildup of sludge and deposits. 
8. Dispersants like alkenyl succinic esters, alkenyl succinic imides, and amino-amidos (i.e. amides of a long-chain fatty acid with a polyamine). They help keep the system free of sediments. 

Types Of Power Steering Fluid 

The fluids contain some specific contents. So, are all power steering fluids the same? No, power steering fluid has different kinds. Even though some ingredients are similar, some are different. Let’s know about the power steering fluid types. 

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1. Synthetic Power Steering Fluid

Such fluids are created in a lab and mostly contain polyesters, polyhydric alcohols, and a trickle of refined petroleum fractions. They are typically ideal for modern vehicles. Manufacturers like Volvo, Toyota, Mitsubishi, Nissan, Porsche, Mercedes-Benz, BMW, and Honda suggest such fluids. However, they suggest using the ones that meet their specifications. You can consider using Royal Purple, Driven, or ATP for the system.  

2. Mineral Power Steering Fluid

It’s mainly made of refined petroleum fractions coming with additives. You can use Penrite, Mineral 1 L, or Febi for vehicles, especially the older ones that are compatible with such fluids. 

3. Auto Transmission Fluid

For power steering systems compatible with ATF fluid, consider using Mercon, ATF+4, Dexron, Starol, and Type F. Typically, many vehicles from the 1970s till mid-1990s use such steering systems that accept ATF fluid. 

How Long Does Power Steering Fluid Last?

The shelf life of power steering fluid depends on the type, whether it’s opened or not, storage condition, usage, and different elements. While the unopened container should last from 3 to 5 years, the opened but unused one can stay good from 2 to 3 years. 

However, the contents of fluid can break down due to metal or sediment contamination, overheating, and extreme pressure. This can reduce the shelf life of the liquid too. 

Not just that, the steering fluid can oxide over time and end up with a change in color and residual buildups on the pump valves. The seals and O-rings can get hard leading to cracks of parts, leaks, and poor performance of the fluid. 

Read Also: What Happens If You Put Wrong Oil In Car?

Frequently Asked Questions 

1. Is Power Steering Fluid The Same As Hydraulic Fluid?

Power steering fluid is a sub-type of hydraulic fluid whereas all hydraulic fluids aren’t compatible with a power steering system. The contents of such fluid give power to the steering system while making it flow through the rack and pinion. As it moves across the parts, it applies pressure to the piston that helps make the wheels turn with ease. 

2. Is Power Steering Fluid The Same As Brake Fluid?

No. Different chemical compositions make power steering fluid different from brake fluid. So, you cannot use them interchangeably. Doing so can lead to severe damage to the steering or braking system. And this can result in unwanted accidents. 

You can use Auto Transmission Fluid as power steering fluid alternative but the vehicle has to be compatible with them. Meanwhile, a solution of soap and water can be an effective brake fluid alternative. So, you can see the difference. 

3. How To Change Power Steering Fluid?

Make sure to turn off the engine before changing the fluid. Then, wipe the reservoir and its cap with a cloth. Check the fluid level with a dipstick fixed to the cap. If it’s below the MIN line, then add fluid while making sure you don’t exceed the MAX line. In case the fluid is above the MIN level, then examine the fluid quality. If you find it cloudy, dark, or foamy, then change it. 

Final Words

That’s all about power steering fluid. It indeed makes driving easy by giving power to the steering system. However, you should check the fluid occasionally so you can change it at the right time.