How Do You Check Transmission Fluid Hot or Cold

Transmission fluid is an essential lubricant for changing gears. With proper transmission fluid action, your car avoids trouble in the automatic transmission while changing gears.

It is essential to check the condition of transmission fluid routinely. There may be a low level of transmission fluid caused by leakage and many other issues that gradually damage the car transmission system.

Just like routine health check-ups, it is vital to check the fluid level of your car on a regular basis.  Transmission oil works as the fluid between the engine and the transmission.

The condition of the transmission fluid should be checked to keep the engine operating smoothly. Check your transmission fluid level by following two methods for the two types of transmission:

Method 1: Checking ATF Using Dipstick

The automatic transmission has a dipstick to measure the transmission fluid condition. The dipstick used to check transmission fluid is similar to that used to measure engine oil. But the difference is that this dipstick is used to check whether the transmission fluid is hot or cold, whereas the engine oil dipstick measures the fluid level.

To check the automatic transmission fluid, follow these 4 steps:

  1. Leave your car in a neutral mode to check the transmission fluid.
  2. There is a locked dipstick inside the hood. Unlock the dipstick and pull it out.
  3. Clean the dipstick well with a cloth and then reinsert it again.
  4. Remove it and check the marked portion.

There should be two markings on the dipstick: one is “Hot” or “Warm,” and the other is “Cold.” If the fluid level comes up before the line marking “Hot,” it will be considered a low level for the transmission system.

In this case, add transmission oil carefully in a small quantity and observe the dipstick until it touches the “Hot” marked line.

If the fluid level touches above the “Hot” mark, it is overfilled, and some fluid should be drained to drop it to the proper quantity. Overfilled transmission fluid causes damage due to overheating.

Be careful while locating the dipstick. The end of the dipstick should be dipped into the transmission fluid tank covering the marked line well.

Method 2: Checking ATF without Using Dipstick

The sealed automatic transmission has no dipstick to measure the transmission level. It needs expert service to check the fluid, though these types of transmission require fewer services or maintenance.

Still, you can check the fluid condition on your own in cases of emergencies or to take preventive measures.  It needs some other tools like an OBD2 scanner and an infrared thermometer as a substitute for a dipstick to work through the refill hole of the transmission.

To check the transmission fluid in a sealed automatic transmission without using any dipstick, follow these 4 steps:

  1. To observe the fluid level with the OBD2 scanner, connect the transmission with the scanner.
  2. Press and hold the brake pedal throughout the whole process.
  3. Start the engine and cycle through the gears to cycle the fluid through the transmission.
  4. Cycle the transmission selector from Neutral to Drive very fast back and forth until the D indicator comes on solid for 2 seconds.

Leave the engine running while checking the fluid level. The OBD2 scanner connects with the transmission and gets a signal through the temperature sensor.

The signal meanings:

No D or Drive = Transmission is too cold. Wait a few moments.

D or Drive light ON solid = Good! Check your fluid.

D or drive light flashing = Too hot; turn off and cool down

Notes: In most cases, you can check and change the transmission fluid independently. But if the condition of your fluid gets worse and is risky, then it is better to repair it in a service center or by a professional expert.  Use the manual guide while checking the transmission fluid. The manual guide tells the car mode while checking the transmission fluid. Follow the directions.  Use the recommended transmission fluid while changing or adding. Be careful when adding fluid that may split over the engine or other external parts.

If your car makes noise after changing the fluid level, recheck or leave it briefly.

Why Is It Necessary to Check Your Transmission Fluid?

The main function of your car’s transmission is to coordinate the engine to the rest of the car, especially to your car’s wheels. To perform all the tasks properly, your car’s transmission needs an ample quantity of transmission fluid.

This fluid is the lubricant to operate the transmission system and change the gears. Like engine oil, transmission fluid helps keep the transmission cool and work spontaneously. So, it is necessary to keep the fluid clean and proportionate.

Low-level fluid or fluid having an unnatural odor or color can cause issues with the transmission. Smooth gear changing is interrupted due to dirty fluid. Unusual noises, hard shifting, delayed shifting, and slipping of gears occur due to low transmission fluid.

Lacking the required level of transmission fluid can result in extensive serious harm. Transmission fluid need not be changed so frequently, just like the motor oil, but it requires routine checks to prevent poor gear shifting. As a preventive method for your car, checking the transmission fluid level regularly is an essential task after a certain period.

The significant changes in the transmission fluid’s color, consistency, and smell should be carefully noticed. The fluid’s dark red, brown, or black color tells its poor condition. Also, the smell of the fluid should be odorless.

If you find there smell like something smoky or burnt, then it indicates damaged fluid. The consistency of the fluid should be a little bit thick and heavy. A thicker consistency level holds the contaminants in the fluid level as well as overheated fluid.

These signs may have been found while checking the transmission fluid. If one or two signs are found, then it is high time to change your transmission fluid. The “Hot” and “Cool” levels should be checked using the dipstick that mainly indicates the proportionate quantity of transmission fluid to operate the transmission properly.

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