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should car be running when adding transmission fluid

Do You Add Transmission Fluid While the Car Is Running?

Cars need different types of fluids to run. From air conditioning refrigerant to motor oil, you must keep an eye on each of these fluids, or else your car may experience extensive wear and tear in no time.

Among the many essential fluids, one that requires special mention is transmission fluid. While most individuals know the significance of changing engine oil, many still have no idea what transmission fluid does.

Transmission fluid lubricates the metal parts and bearings present inside a car’s gearbox. It also ensures friction and hydraulic pressure so that the internal components of a car function without any hassle.

The following write-up aims to answer frequently asked questions about transmission fluid. Please check it out right now.

Do you add transmission fluid while the car is running?

Do you leave the car running when adding transmission? That’s a question you will come across several times.Well, according to the best automobile experts, a car’s engine must run when one adds fluid to the transmission. That said, the transmission should be in park and the handbrake should be activated for extra safety.

How long should a car run before checking transmission fluid?

A car will run for two to three minutes before you have to check the transmission fluid. Keep the car in the neutral or parking mode and always keep the handbrakes on. Since the car is running, please do not throttle and overheat it. When it is winter, please run the car multiple times. Otherwise, you will not be able to take an appropriate reading of the transmission fluid.

How to add transmission fluid to your car?

After using the car for around 30,000 to 60,000 miles, you have to add more transmission fluid. Please keep in mind the below steps when adding transmission fluid to your car.

Purchase the right transmission fluid:

Purchasing the right transmission fluid is necessary. Both traditional and synthetic fluids pros and cons. Synthetic fluids are perfect for modern vehicles and high performance engines. If your car is of an older model, you must use a traditional fluid.

Turn off your car and set its transmission in parking or drive mode:

Keep the transmission of your car in drive or park mode. Please set the parking brakes too. The car must run for at least three minutes based on your environment.

Open the dipstick and check your transmission fluid level:

Do you add transmission fluid where the dipstick is? Yes, you do. You also have to open the dipstick to check the fluid level. Open the hood of your car and there you will find the dipstick hole.

Insert a funnel in the hole:

Insert a funnel so you can add the transmission fluid inside the dipstick hole without any hassle.

Add the transmission fuel:

Add the fluid and keep checking so that you do not end up overfilling the dipstick. You will need 13 quarts to fill the entire transmission.

Change transmissions while filling:

Change the transmissions when filling the fluid so that it runs throughout the gears.

Properly seat the dipstick after finishing:

After you are done filling the fluid, please seat the dipstick properly.

Can you add transmission fluid while the car is hot?

can you add transmission fluid when car is hot
Adding transmission fluid when car is hot

Can you add transmission fluid when car is hot? Many people have this query and you may have too. Yes, you can add fluid when the car is hot. When the car is hot and is at the best possible temperature, it seems perhaps the best time to add transmission fluid. You can take the fluid readings accurately.

Can you add transmission fluid while the car is off?

Transmission fluid can be added to your car while it is off, but it may damage it. It is possible to overfill your transmission fluid in your car. If you turn on your car, it may not work properly or get jammed.

Why should you check transmission fluid when the engine is running?

Should you check transmission fluid while car is running? According to top-notch automobile manufacturers, you should. Why? Because of the two reasons stated below.

  • Fluids expand when it gets heated:

Almost all fluids expand when they absorb heat. Transmission fluid does the same. You can get correct readings of the fluid if the car is running.

  • Transmission fluids do not stay in the pan:

Torque converter stays beneath the fluid if your car’s engine is running. If the engine is off, the transmission fluid will build up at the bottom of the pan. You would not get a proper reading otherwise.

How can you know if your car needs transmission fluid?

As evident from the discussion until now, transmission fluid is an integral part of cars. Now that you know the answer to common queries like – can you add transmission fluid while the car is off, it is time to find out the signs that a car needs transmission fluid.

  • Warnings on your dashboard:

If the check engine light on the dashboard pops up, you must go to your nearest service center and get your car investigated. There are plenty of reasons why the light is on, one of them being a problem with the transmission.

  • Burning smell from your car:

Is your car generating a burning smell? If yes, the transmission fluid may have become overheated and need changing immediately.

When the transmission is excessively hot, high friction occurs between the components, which in turn causes grime to accumulate and ultimately corrode the transmission. If neglected, the transmission will damage itself.

  • Having difficulties in shifting gears:

A fully functional transmission can shift between the gears and there will not be any slippage. Low levels of fluid can force you to miss gears and result in a vibrating sensation.

Slipping gears occasionally may seem like a tiny issue initially, but it is always a great idea to monitor the transmission. This way you can avoid expensive repairs down the road.

  • Transmission fluid puddles under the car:

The fluid inside the car’s transmission is the only way it receives lubrication. Transmission fluid also acts as a conditioning and cleaning agent. Leaks indicate transmission issues, so if you see fluid puddles under your vehicle, please run to a service center.

Please get in touch with an authorized dealer to get the transmission inspected. The repair may be an easy replacement of a failed hose or gasket.

How often do you have to put transmission fluid in your car?

You should put transmission fluid in your car if it has run for a minimum of 30,000 miles and a maximum of 60,000 miles.

How much transmission fluid to add if empty?

If your transmission is fully drained, you will need around four to twelve quarts of transmission fluid to fill it up.


I hope the above discussion helped you learn everything about transmission fluid. The next time you are adding or changing it, please refer to the information you got from here.

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