Is Transmission Fluid Flammable? (Answered)

Transmission fluid is a liquid that is applied to a car occasionally to help the transmission sister perform optimally. Apart from fuel, it is another essential car facilitator. Once in a while, you need to top off or change your transmission fluid to keep your car in check.

But is transmission fluid flammable? Is it safe to do it yourself, or is it dangerous enough to cause a fire hazard?

According to OSHA, transmission fluid is not flammable, but it is combustible! Transmission fluid has a flashpoint above 199.4 degrees Fahrenheit. Its flashpoint is between 302- and 383-degrees Fahrenheit (equal to 150 and 195 degrees Celsius).

Can Transmission Fluid Catch On Fire?

Transmission fluid (ATF) can catch on fire, but there are certain cases it won’t, primarily because the liquid doesn’t burn as fast and easy as lighter fluid or gasoline. In other words, you have to heat it a little longer before it can catch fire.

But the good news is that with adequate precautions, you can deal with transmission fluid reasonably well, and there won’t be a need for any significant fire outbreak. 

What Temperature Will Cause It to Ignite?

Transmission fluid will not combust unless its flashpoint temperature reaches around 300 degrees, its average flashpoint.

Then, whenever you continue to heat any liquid within or above its flashpoint, it can emit vapors enough to catch fire. However, before it can cause a spark, there must be a source of ignition around.

Since its flashpoint is over 199.4 degrees Fahrenheit, the OSHA (Occupational Safety & Health Administration) consider Transmission fluid a non-flammable liquid. However, it will naturally ignite when it is up to 400 degrees Fahrenheit.

That is when it is at auto-ignite range. In other words, it can catch fire without any external ignition source.

Even though that is excessively hot, you have nothing to worry about, as it can hardly get to that point under normal circumstances.

However, activities like welding and grinding tend to breed byproducts hotter than this and, therefore, cause transmission fluid to lit up. So, you have to prevent both from coming together.

Again, avoid anything like mist or spray around the transmission fluid, as it could probably catch fire at a much lower temperature than 400 degrees mark. But, let’s assume there will be nothing like such, yet, prevention, they say, is better than cure.

What Happens If Transmission Fruid Is Burnt?

Once a transmission fluid heats up more than usual in the transmission, it will ooze out a burning smell, which means that you should invite a mechanic and get your vehicle for proper servicing because it is a bad omen.

The primary signs of burnt transmission fluid include burning or smoking smell, fluid leakage from the transmission and black than its usual red, and difficulty while shifting gear. Leakage of transmission fluid could end up on a heated surface in the engine and could initiate fire. 

Can Transmission Fluid Start a Fire? (Is Transmission Fluid Flammable?)

Of course, transmission fluid can start a fire. This will likely occur when the transmission has a leakage that drops on any hot surface of your engine.

Therefore, adhering to the proper process when pouring fluid into your transmission is essential. Again, always check the transmission and the fluid occasionally to ensure all is in good condition.

Note: Transmission fluid will hardly start a fire if you always do the needful by topping up the fluid in your vehicle.

What is the Flashpoint of Transmission Fluid?

As far as transmission fluid is concerned, its flashpoint ranges from 302- and 383-degrees Fahrenheit, equal to 150 to 195 degrees Celsius. However, as we mentioned earlier, it depends on the transmission fluid type.

Moreover, this flashpoint is more than the temperature that is present in the natural daily operation of your vehicle and workshop, even though certain activities can only ascertain it.

So, it would be best to avoid letting the transmission fluid close to various heat sources or sparks to prevent a fire hazard.

Can I Put Transmission Fluid In a Hot Car?

Putting a transmission fluid in a hot car is an understatement; you can also put it into a vehicle while its engine is running.

However, since definitions of ‘hot’ vary, it would depend on which one you are talking about. For example, if your definition of ‘hot’ implies putting transmission fluid into a car already on fire, it would be a bad idea.

But the one we recommend is the one that involves putting transmission fluid into a car when the engine is running but idling, with transmission ready to park with your parking brake on. This is because transmission fluid expands when it is going through a heated transmission.

So, if you apply a fluid to it when the vehicle is very cold, anytime you power the car, it would cause the fluid to expand, and it will lack a place sail.

This will cause a break in transmission, and fluid will began to leak onto the engine. Hence, it is best to pour the fluid when the engine is running, but the car is idling.

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