Can Power Steering Fluid and Brake Fluid Be Used Interchangeably?
3 Answers
Brake fluid and power steering fluid cannot be used interchangeably. Brake Fluid Explanation: Brake fluid, also known as hydraulic brake fluid, is a liquid medium that transmits braking pressure in hydraulic brake systems, used in vehicles equipped with hydraulic braking systems. Power Steering Fluid: Power steering fluid is a type of transmission fluid, with a key indicator being its low-temperature fluidity. Even when temperatures drop to several tens of degrees below zero, it does not thicken, allowing the steering system to operate smoothly. Replacement Intervals: Brake Fluid: Generally, it is recommended to replace brake fluid every 2 years, but this interval can vary depending on usage conditions. Power Steering Fluid: It is recommended to replace power steering fluid every 40,000-50,000 kilometers or every 2-3 years.
Thinking of mixing fluids in an emergency? Really not recommended. Brake fluid and power steering fluid are completely different—the former must withstand 400°C to prevent vapor lock, while the latter focuses on lubricating the power steering pump. Even a temporary mix can cause the additives in power steering fluid to corrode brake seals. It might seem fine for a couple of days, but when you change the fluid a month later, you’ll likely need to replace the entire set of rubber components. Last week, my cousin had issues after mixing them and ended up paying over 700 yuan for repairs. Remember to keep a small bottle of power steering fluid in your trunk—the one labeled ATF on the cap is the right one.
As a mechanic with 20 years of experience, I've seen countless cases of steering gear removal due to mixed fluid usage. Brake fluid must use glycol-based DOT4, while the steering gear requires ATF automatic transmission fluid with completely different anti-wear formulations. Mixing them causes valve sticking, heavy steering wheel, and squeaking noises. Last year, a car owner mixed them for three months, grinding grooves into all power steering pump vanes, costing 2800 to replace. The most intuitive way is to check reservoir cap colors: yellow cap for steering fluid, black/white cap for brake fluid.
