Can sewing machine oil be used as a substitute for brake fluid?

[GenesisFitz]

Brake fluid cannot be replaced with sewing machine oil, as it may lead to brake failure. Below is relevant information about automotive brake fluid: Regular replacement of brake fluid: The volume of brake fluid changes with temperature variations. Therefore, the brake fluid reservoir is equipped with a vent hole. The air drawn in through this hole contains moisture or impurities, which can be absorbed or dissolved by the brake fluid, thereby lowering the boiling point of the moisture-containing brake fluid. When a car brakes for an extended period, the temperature of the braking system rises, making it prone to vapor lock in the brake lines, where air is compressed, potentially resulting in reduced braking force or brake failure. Hence, for driving safety, brake fluid must be replaced periodically. Characteristics: Automotive brake fluid has a very low freezing point, ensuring good fluidity in low temperatures; it also has an extremely high boiling point, preventing vapor lock under high-temperature conditions.

[MacDamian]

I firmly believe that sewing machine oil must never be used as a substitute for brake fluid. With over 30 years of driving experience, I've seen many friends resort to improper oil substitutes to save money or in a rush to fix their cars, only to cause serious disasters. Brake fluid is specifically designed as a hydraulic fluid to withstand high pressure and high temperatures. If lightweight lubricants like sewing machine oil are used instead, their boiling points are too low, easily forming bubbles and vapor lock during high-speed braking, leading to complete brake system failure—which can be life-threatening. I still remember a neighbor's car nearly rear-ending another on the highway due to this issue; fortunately, they stopped in time to avoid an accident. That's why seasoned drivers always remind you to only use proper DOT3 or DOT4 brake fluid and never cut corners. If you're unsure how to handle it, it's best to have a professional mechanic inspect the brake system and replace the brake fluid regularly for safety.

[SanEmery]

As a young driver with several years of experience, I often see people online discussing whether sewing machine oil can be used as an emergency brake fluid. Let me tell you, this absolutely doesn't work! Brake fluid and sewing machine oil are completely different things. Brake fluid must withstand high temperatures and pressure, otherwise too many bubbles can lock up the entire system - how dangerous is that! Sewing machine oil has such a low boiling point; I've tried applying it to machinery before, and it just melts and leaks with a bit of heat. Imagine replacing it and having brake failure while driving - at best you'd scrape your car, at worst you'd cause an accident. Isn't that just asking for trouble? Last time during maintenance, my mechanic said to just use original brake fluid and not mess around. Saving a few bucks isn't worth compromising safety. Think about it another way - regular brake fluid checks are cost-effective and not troublesome at all.

[Nevaeh]

I usually tinker with cars and find the brake system quite particular—absolutely no mixing of oils is allowed. Brake fluid is a high-pressure hydraulic fluid designed to prevent boiling and compression at high speeds. Sewing machine oil, with its different chemical properties, has a low boiling point and weak viscosity. Adding it can corrode rubber components, cause leaks, and form bubbles, leading to brake failure. This design principle is critical; any mistake could result in complete brake failure, posing significant risks. So, just stick to dedicated brake fluid and avoid reckless experiments. During maintenance, check the fluid reservoir to ensure it's free of moisture and impurities.