How to Change Auto Transmission Fluid
- 1). Start the car and leave it in park or neutral. Open the hood of the car and locate the automatic transmission fluid dipstick. Typically this dipstick will have ATF typed on the front, standing for automatic transmission fluid.
- 2). Pull the dipstick out and wipe it clean with the rag. Stick it back into the slot, pull it out again and read it. There will be two lines on the dipstick. If the fluid does not show up at the second line, your car is low. If the fluid is a reddish color, it's still new and does not require changing. If it is dark brown or black, it is dirty and could benefit from a change.
- 3). Put on your emergency brake. Locate the cooling line, which runs from the transmission to the radiator. Disconnect it, making sure to not let the oil spill as soon as you do so. Connect the rubber tubing to the end of the line, and place it in the pan or disposable bottle. Let the fluid drain out until it stops. Reconnect the cooling line. Save the drained fluid, because you will have to dispose of it at an auto recycling center.
- 4). Remove the drain pan under the transmission by unscrewing the bolts. Clear built-up grime, sludge, dirt and old oil with a bit of new transmission fluid and a rag.
- 5). Take out the filter and replace it with a new one. Before taking the old filter out, study the way it is set. Replace the new filter in the exact same way. Be careful not to lose the O-rings or reset them in a different way.
- 6). Replace the old gasket with the new one, which seals the transmission drain pan.
- 7). Reinstall the pan you just cleaned. Tighten the bolts by hand. Tighten it close to, but not exactly at, maximum tightness with a wrench. You do not want these bolts to be too tight. Come with three turns of maximum tightness.
- 8). Refill the transmission with new fluid. Place a funnel over the slot where the dipstick goes; the dipstick should still be removed. Add fluid through the funnel little by little. Continually check the level of the fluid with the dipstick while the car is running to avoid overfilling the transmission, which may ruin it.
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