If you have determined that your hydraulic oil needs to be drained, you will want to make sure that you are removing as much of the substance as possible. This is necessary if you want to ensure that your new oil, whether it be Mobil DTE 25 or Fuchs Renolin B10 VG32, can work to its full potential, without any issues from leftover oil. Luckily, there are some simple ways to increase the amount of oil you remove during a drain.
Hydraulic cylinders
One simple way you can make sure your drain goes as smoothly as possible is put all of your equipment’s hydraulic cylinders into the closed position. If cylinders are closed, there is very little oil to be found in the machine’s components, which means you will be able to drain much more of the old oil.
Drain ports
Different hydraulic systems have different numbers if drain ports, which can be found in several different locations, However, if you are in doubt, it is almost certain that your machine will have a central drain port located on the main reservoir. This port will allow you to drain the bulk of the system’s oil, but you should still check if your system has individual component drains and use these to get rid of even more oil, if possible.
Return-line filters
Another method of draining hydraulic systems you can employ is to pull any return-line filters that you can find. Return-line filters tend to hold a lot of oil, so by pulling the lines, more drainage is possible.
Circulate air
Without exception, when you perform a hydraulic drain, you must also allow air into the circuit. It is vital that you install breathers on all breathing ports, which will remove moisture and debris from air going into the system, thus preventing contamination.
Portable filter carts
Portable filter carts might be more commonly used to filter incoming oil, but you can also use them to drain old oil much more quickly without opening the reservoir to outside contaminants for too long.
Check manufacturing instructions
Although most hydraulic systems will be drained by first removing the plug, replacing the filters and then adding fresh oil, it is never a bad idea to consult the system’s operating manual, as you will want to be 100% sure that any measures you take will not hinder the process.