The Anyang power hammer is designed to give you many decades of maintenance free forging. But there are several maintenance items that are important:
1. There are two grease zerks for the crankcase and connecting rod. These grease points should be greased at least once a month. Pump enough grease where you see grease coming out from the bearings or where the shaft exits the crankcase.
2. Using the proper type of oil is important to hammer life and performance. I recommend using 10 to 30 weight (depending on the temperature of your shop). If your oil is not flowing adequately then use a lighter oil. Even in Texas, I use 10 wt. oil most months. It is also important to use non-detergent oil. Oil is a consumable (it is not recycled) and operating temperatures are low (compared to car engines) so it is not important to purchase expensive oil. I buy the lowest cost oil that I can find from the local agriculture supply store. I also purchase it in 2.5 gallon bottles.
3. The most critical component of hammer performance and life is the amount of oil you use. Oil in not only a lubricant, it is a "sealer". On all of the new hammers, we have eliminated the front oiler to the ram. The rear compressor piston is always circulating when the hammer is running and it always needs an oil supply. The front ram will be fed oil from the rear compressor through the air valves. I recommend that when you first start the hammer, turn the oil valve all the way up and get the oil flowing. When you start forging, you can then adjust the oil down. I recommend trying to dial the oiler to one drip every 3 to 6 seconds. With proper oiling, the ram will be 'moist" with a film of oil. I also say "if you make a mistake, use too much oil... it never hurt the hammer." Too little oil long term will shorten the life of the hammer... just like a car engine.
4. Once a year, check the plastic oil lines for stiffness, discoloration, or cracking. Replace them if necessary. The plastic lines can be purchased for a dollar or two at a local building supply store.
5. After a few hours of forging, tap on the die keys to make sure they are tight.
6. Once every two months, check bolts for tightness. After the first 6 months of usage, check the connecting rod nuts for tightness.
7. Depending on your usage, but every two or three months drain the oil at the bottom of the hammer using the petcock on the side of the hammer.