Brake and power steering fluids are both hydraulic fluids used in various automobile vehicles. However, they have striking differences that make them not a substitute for each other but individual hydraulic fluid. So, can you use brake fluid for power steering?
Definitely NO. Both fluids are poured into separate systems in your vehicle and are not manufactured with similar compositions, making them unique to their specific functions.
If these two hydraulic fluid forms are substituted with one another, the effects are dangerous to your vehicle, which you will know later on as you read this article.
But note this fact, brake and power steering fluids are separate hydraulic fluids, and they function independently, so ignore any misconception or uncertainty about this and get this known.
What is Brake Fluid?
Brake fluid is an essential car fluid that lubricates the car braking system and provides the required pressure to stop the vehicle.
One of the most crucial fluids your car needs is brake fluid. When you press the brake pedal, your car would not be able to stop without brake fluid. Instantaneous braking is what is intended.
The brake fluid is an essential component of different types of car braking systems. It lubricates the antilock braking system, brake pistons, and valves.
This fluid provides hydraulic pressure to the car braking system. So, the first thing you should examine if you notice any delay or unusual sensation in your brakes is this fluid.
What is Power Steering Fluid?
The power steering fluid is required to steer the car effortlessly and lubricate the steering system.
The power steering fluid is yet another essential car fluid that keeps your car in good condition. Your car can steer effortlessly as a result of power steering fluid since the fluid lubricates and cools the components including.
- Power steering pump,
- Gearbox,
- Valves, and
- Seals.
It’s crucial to make sure the fluid level isn’t low or empty or you will face issues such as a hard steering wheel or car stalling.
Can I Use Brake Fluid For Power Steering Fluid?
Can brake fluid be used as power steering fluid? Definitely No, these fluids are not supposed to be mixed or used interchangeably. They’re hydraulic fluid but they have different chemistries.
The oils themselves also have their parameters and viscosity grades, mixing them is very dangerous or at least will damage or reduce the vehicle’s life. So are there consequences attached to this error?
The brake fluid is a lot more abrasive and it is alcohol-based because a petroleum-based fluid would erode the rubber seals and hoses; which would cause a system failure.
Using brake fluid in the power steering system can lead to damage to the seals and other components of the power steering system. This can result in leaks, reduced steering performance, and potential safety hazards.
While power steering fluid is petroleum-based and a power steering (rack and pinion type) system has a lot of metal-on-metal contacts.. In addition to being a pressure transfer medium, it also functions as a lubricant. Brake fluid does not make for a good lubricant.
Therefore it’s suitable to use only power steering fluid for the power steering system and brake oil for the brake system as all automobiles give the finest performance.
Though in some unwanted cases, where there are no other alternatives, brake fluid can be used as power steering fluid, it should be the once in a lifetime.
You should never use the brake fluid as power steering fluid because this system requires fluid with a high boiling point. However, you can interchange the power steering oil for brake fluid in some dire situations since both are hydraulic fluid.
Differences Between Brake Fluid and Power Steering Fluid for Vehicles
When comparing brake fluid and power steering fluid for vehicles, several key differences exist.
- Working intend
- Chemical composition
- Fluid color
- Contamination and maintenance
- Compressibility
- Types and manufacturer recommendations
- Boiling point
- Compatibility with components
- Hygroscopic properties
#1. Working Principle.
Brake fluid is primarily used in the braking system, and its main purpose is to transfer force into pressure, amplifying the braking force.
It ensures that when you press the car brake pedal, the given force is transmitted directly to the brakes, enabling efficient and safe stopping.
On the other hand, power steering fluid is used in the power steering system to enhance steering effort by reducing engine drag.
It optimizes the performance of the power steering system, making it easier for drivers to turn the wheels, and acts as a lubricant for various steering mechanisms, minimizing wear and tear.
#2. Chemical Composition.
Brake fluid is typically glycol-based or silicone-based, chosen for its high boiling point to prevent vaporization during braking.
Glycol-based brake fluids, such as glycol-ether, are commonly used due to their superior performance in high-temperature environments. These fluids also resist moisture absorption, ensuring consistent performance over time.
Conversely, power steering fluid can have various compositions, including mineral oil-based or synthetic blends.
The formulation of the power steering fluid aims to optimize the performance of the power steering system, providing lubrication to metal components and minimizing wear and tear.
#3. Fluid Color.
Brake fluid is typically clear to yellowish in color, allowing for easy inspection of its condition and level in the reservoir. Its transparency is a key characteristic that distinguishes it from power steering fluid and other vehicle fluids.
Alternatively, power steering fluid can vary in color, often appearing as red, brown, or even green, depending on the manufacturer and type of fluid. This variation in color serves as a distinguishing feature, aiding in identifying power steering fluid.
#4. Contamination and Maintenance.
Brake fluid is susceptible to moisture absorption, which can lead to contamination and compromise the efficiency of your braking system as time passes. Regular maintenance and periodic replacement are crucial to ensure the reliable performance of your brakes.
However, power steering fluid can also become contaminated over time, but the sources of contamination are different. Contaminants in power steering fluid can hinder the smooth operation of the steering system and potentially cause wear and damage.
#5. Compressibility.
Brake fluid, being non-compressible, plays a critical role in ensuring consistent and reliable brake performance. When you press the brake pedal, the force is transmitted directly to the brake system without any yielding to pressure.
This non-compressible nature allows for immediate response and effective braking, ensuring your safety on the road.
On the other hand, the power steering fluid is compressible, serving a different purpose. Its compressibility allows smoother and easier steering by reducing the effort required to turn the car’s wheels. This makes steering more effortless and enhances the overall driving experience.
#6. Types and Manufacturer Recommendations.
Vehicle manufacturers often recommend specific types such as DOT 3, DOT 4, or DOT 5 for brake fluid.
These types have different characteristics and are suitable for different applications. Follow the manufacturer’s recommendations as they consider factors like system design and expected usage.
Power steering fluid, however, can vary depending on the vehicle manufacturer and system design. It may include synthetic, nonsynthetic, or automatic transmission fluid (ATF).
To ensure the functionality and longevity of your power steering system, select the appropriate power steering fluid recommended by the manufacturer.
#7. Boiling Point.
Brake fluid typically has a high boiling point, exceeding 300°C (572°F). This high boiling point is crucial as it ensures the stability and effectiveness of the fluid, even under extreme braking conditions.
On the other hand, power steering fluid also possesses a high boiling point, approximately 600 degrees Fahrenheit. This characteristic is essential for preventing overheating of the power steering pump and maintaining the functionality of the steering system.
#8. Compatibility with Components.
Brake fluid is carefully formulated to be compatible with the braking system’s rubber seals and hoses. This compatibility is crucial as it prevents corrosion and ensures the long-term effectiveness of the braking system.
In contrast, a power steering fluid is designed to preserve the power steering pump and keep the steering mechanism well-lubricated. Using the correct fluid is essential for preventing damage to system components and ensuring smooth steering operation.
#9. Hygroscopic Properties.
Brake fluid, being hygroscopic, can attract and retain moisture from the surrounding environment. This characteristic prevents moisture buildup within the brake system, as moisture can lower the fluid’s boiling point.
In contrast, power steering fluid doesn’t exhibit hygroscopic properties. While it enhances steering and lubricates components, its primary function doesn’t include preventing moisture accumulation. Therefore, power steering fluid isn’t designed to absorb moisture like brake fluid actively.
Comparison Table Between Brake Fluid & Power Steering Fluid
| Aspect | Brake Fluid | Power Steering Fluid |
| Purpose and Function | Transfers force into pressure for efficient braking. | Enhances steering effort and lubricates steering components. |
| Chemical Composition | Typically glycol-based (e.g., glycol-ether or silicone). | Can be mineral oil-based, synthetic, or other blends. |
| Compressibility | Non-compressible; maintains consistent pressure. | Compressible; reduces steering effort. |
| Boiling Point | High boiling point, typically 300°C (572°F). | High boiling point 600°F. |
| Compatibility with System Components | Compatible with hoses and rubber seals. | Designed to preserve power steering pump and lubricate components. |
| Hygroscopic Properties | Hygroscopic; absorbs moisture to prevent system corrosion. | Non-hygroscopic; focuses on steering and lubrication. |
| Fluid Color | Typically clear to yellowish. | Varies in color (red, brown, or green). |
| System Control | Critical for braking control, ensuring vehicle stops effectively. | Enhances steering control, reducing effort for the driver. |
| Contamination and Maintenance | Susceptible to moisture contamination; requires regular replacement. | Prone to contamination, necessitating maintenance for optimal performance. |
| Fluid Types and Manufacturer Recommendations | Different types (e.g., DOT 3, DOT 4, DOT 5); manufacturer recommendations vary. | Varied types based on manufacturer and system design; follow manufacturer recommendations. |
What happens if I use brake fluid for power steering?
In case you accidentally put the power steering fluid in the brake fluid’s reservoir, the seals of the system will begin to swell due to contaminants of the former fluid. The brake lines get blocked as the seals swell and advance.
Take the example of the master cylinder’s return ports. This port is blocked by the swollen seals as a result the fluid returns to the reservoir when the brake pedals are released.
The brake fluid expands due to heat generated by braking. The brakes engage and the wheels lock if the expanded fluid does not go back to the reservoir.
Next, you may face spongy brake pedals as one of the first symptoms of car brake failure. Complete failure of the braking system occurs when the contaminants of the power steering fluid destroy the rubber parts of the system.
How to Check Power Steering Fluid?
#1. Locate Reservoir.
The first step to checking the power steering fluid is finding the appropriate reservoir. After all, your car probably has several containers filled with fluid under the hood.
You can look in your owner’s manual to find its location, as each model is different. It should be a small container that’s clear and it usually contains a black cap on the top.
#2. Examine Dipstick.
If the vehicle has a dipstick system, there will be marks on it to look at. It should remind you of an oil dipstick. Remove the cap for the dipstick and wipe it clean with a shop towel.
If there’s no dipstick, you will examine the tank by the marks on the side. There should be a MAX and MIN line that the fluid should rest between.
#3. Double-Check.
Put the cap back on so the dipstick rests back in the fluid. You want to double-check it to see what level the fluid is at.
Most dipsticks contain marks that either say MAX and MIN or Full Hot and Full Cold. Either way, you want to ensure the level is located at the appropriate spot on the dipstick.
#4. Fill, if Needed.
If the power steering system is low, you need to top it off. Fill up the reservoir until it reaches the proper level.
If the fluid looks contaminated, you might want to perform a power steering flush instead. Most manufacturers recommend performing this maintenance task every 40,000 to 80,000 miles.
How to Fix the problems caused by Brake fluid in the power steering?
You already know by now that using your brake fluid in your power steering system should not be considered an option. This is mostly because the brake fluid is acidic and has low lubricating properties.
But if you’ve already done or done this without knowing, then you need to flush your vehicle’s power steering system thoroughly, but can I use transmission fluid for power steering fluid?
Yes, you can try that but ensure you check the vehicle’s manufacturer’s recommendation. The detailed process of how to do this is shown below. But you should do this only when you are confident you will execute the whole process. If not, call for professional help.
When you realize you accidentally poured your brake fluid into your car’s power steering system. Do not turn on your car engine to drive to the mechanic’s shop or anywhere. Leave your car to remain at rest.
This should reduce the extent of damage that could have occurred. Since you did not turn on your car engine, the brake fluid poured will rest inside the reservoir.
Get your mechanic tools box, open the reservoir of your power steering fluid, and suck out as much fluid as possible. Ensure you have a can to retain the fluid.
Lift your vehicle off the ground with your jack or car lift so your wheels aren’t touching the ground.
You need to know how to use any of the lift options. If not, do not attempt using them. When your vehicle is lifted, turn your steering wheel around so more fluid will flow to the reservoir. Try to get it out of the reservoir. You can get a baster to help you out.
You now have to disconnect your low-pressure line. You can use the right screwdriver type to take off the clamp.
After disconnecting, direct the line into a container and allow the brake fluid to drain out. While the brake fluid is draining out, turn your steering wheels to the left and right direction to help drain out more of the brake fluid.
When you notice there is little or no brake fluid left in your reservoir system. Pour in a new power steering fluid and allow it to drain out of the system into a can.
You should do this about three times. When you finish this process, couple your power system back together and pour fresh power steering fluid into your reservoir.
You should be very careful while flushing out the brake fluid from your power steering system. If you do this correctly, you shouldn’t have to call a mechanic to help you out. It’s almost the same process a professional will take.
But in a situation where you’ve already driven your vehicle after pouring brake fluid into your car’s power steering system. You need to get your vehicle immediately to a mechanic to have the system flushed and also to fix any damage that could have happened.
You might be thinking, can I use hydraulic fluid for power steering? Well, this depends on the type of hydraulic fluid. It is best to stick to the recommended fluid.
FAQs.
Q: Can you mix brake fluid and power steering fluid?
No. You should not mix brake fluid and power steering fluid. Mixing or using these in the wrong system can cause serious damage to your car or even cause accidents.
While both fluids are designed to lubricate and protect your car’s components, they serve different purposes and mixing the two can cause problems.
Q: Can you use transmission fluid instead of power steering fluid?
It depends, in many older vehicles, the transmission fluid and power steering fluid were the same. However, in modern cars you will often find that these two fluids differ from each other. Check your owner’s manual and use only a compatible fluid for your vehicle.
Q: Can you use brake fluid for anything else?
Brake fluid is a type of hydraulic fluid that is used in brake and clutch systems. While brake fluid is not something you can just use for anything else, it does have a few other uses beyond braking.
Sometimes brake fluid can be used to clean metal parts, and brake fluid can also be used as a hydraulic fluid for other applications, such as hydraulic jacks and lifting equipment.
Q: Can you use transmission fluid as brake fluid?
No. Transmission fluid should not be used in place of brake fluid. Using transmission fluid in your brakes can cause damage to brake components and may even result in loss of brake power, which can result in a serious accident or even death.
Final Words
Now you know the differences between these two forms of fluid, so if anyone asks, what can I use instead of power steering fluid? We always tell them to stick to the recommended fluid, we might provide any other safe alternative if any.
With this knowledge, can you use brake fluid for power steering fluid? You know the answer already. Even if there are other available substitutions, always check your manufacturer’s manual before taking any action.