An oil bath air filter is the type of air filter used on tractors to keep dust and dirt out of the engine. The filter is submerged in an oil bath and when the dirty air travels into the filter, it gets trapped in the oil so it can't harm the engine. The oil in the oil bath filter needed to be changed every day or so, and the oil bath filter needs to be cleaned every few months as well.
Remove the oil bath filter from the tractor and dump the old oil in an oil disposal bin.
Fill a bucket full of kerosene and soak the filter in the bucket for 15 to 20 minutes. Agitate the filter every two to three minutes.
Fill a bucket full of hot water and 2 tbsp of dish soap. Place the filter into the water and allow it to soak for 20 minutes.
Empty the buckets of water and kerosene. Fill the water bucket with fresh water and soak the filter to rinse it off. Keep emptying and refilling the water bucket until the filter is clean.
Refill the other bucket with kerosene and place the filter into it one last time.
Allow the filter to air-dry and place new oil in the oil cup. Place the filter in the oil cup and place it back into your tractor.