How to judge whether the old oil in the oil tank of the FF77DRS100M4 reducer is stagnant and drained cleanly

To determine whether the old oil of the FF77DRS100M4 reducer has been drained cleanly, you can follow the following steps to observe and operate:

1. Observe the oil dripping state at the oil drain port

This is the most direct method. When the oil flowing out of the bottom oil drain plug changes from a continuous flow to intermittent oil droplets, and finally stops dripping completely, it means that most of the oil has been drained.

2. Open the top vent

Before draining the oil or when the oil drain is not smooth, be sure to open the breather (or breather cap) on the top of the reducer. This can balance the air pressure inside and outside the box, allow air to enter, so that the oil can flow out more smoothly, and avoid incomplete oil drainage due to the formation of negative pressure inside.

3. Open the side oil level plug

Open the oil level screw plug (or filler screw plug) located on the side of the box. This operation has two benefits:

Auxiliary air intake: Similar to opening a breather, it can provide more air intake channels inside the box and speed up oil drainage.

Check the residue: After the oil is basically drained, you can observe the inside through the oil level hole, or shine it with a flashlight to check whether there is still a large amount of oil accumulation.

4. Slightly shake or turn the device

Under the premise of ensuring safety (the equipment has been powered off and fixed), you can gently shake the reducer box or manually turn the input shaft. This helps collect residual oil accumulated in dead spots such as gear meshes and bearing seats to the oil drain port for discharge.

5. Use oil suction pump

If the oil cannot be completely drained through the oil drain port, you can use an oil suction pump (or syringe) to extend from the oil level hole or filler port to completely suck out the residual oil at the bottom and corners.