Proper Procedure for Hydraulic Oil Changes

Good maintenance on any machine is the number 1 practice that any service team must follow. The life of any machine rely on it maintenance, on hydraulic equipments the life of it components rely on scheduled oil changes and proper oil use. it desirable to maintain the conditions of the hydraulic oil under observation. If the oil is kept clean, in good condition, and its viscosity within the original parameters, it should be left in the tank of the equipment, if on the contrary, there is an indication of any variation, it should be changed. The omission of this simple process is the cause of more than 90% of the damage in the hydraulic systems, the failure in the replacement of the oil causes the premature failure of its components.

No rule can be given for hydraulic oil change, due to the great variety of service conditions, therefore, only experience and good judgment can truly dictate how long the service period can be for a particular operation. Regular testing of the oil, with the supplier or manufacturer thereof, can help you determine the right moment for the hydraulic oil change. Of course, the operating temperature, type of service, pollution in the working environment, quality of the filtration and the same quality of the oil, have a considerable influence on the range of services.

What oil to use? When to change it?

The basic recommendations for oils are those that meet the requirements classified by SAE or API as of maximum severity. These oils provide the safety of adequate protection for wear, as well as excellent chemical stability under extreme operating conditions.

Always consult with the manufacturer of the hydraulic components on the types of oils admitted by them, in most cases, manufacturers of hydraulic components perform durability tests of their components with the various types of commercial oils.

The viscosity of the oil is also an important factor, and should not be overlooked. The environment and the work place of the hydraulic equipment have a significant influence on the hydraulic oil, which is why a viscosity must be chosen that is in accordance with the working environment of the equipment.

Oil renewal of a system.

When changing the oil in a system, it is advisable that the reservoir be completely emptied, so that nothing remains that could contaminate the new oil. Allow enough time for all possible oil to come out of the system. In most cases, purging at the lowest point of the system helps considerably. It is also advisable to drain the oil only after it has warmed up, in this way, the oil impurities are suspended in the oil itself, and can be removed more easily.

Systems that use accumulated deposits that interfere with the operation of the equipment must be rinsed with low viscosity oil. Washing with an oil containing a rust-inhibiting element protects the surface of the metal from rust formation after the hot oil used to wash the reservoir has been drained.

When the hydraulic oil is placed to operate the already clean system again, it must always be, by means of an external 25 micron filter, it is important that the new oil is clean and free of any substance that may cause improper operation and excessive wear of some element of the system.

Never wash the oil tanks with water, the water and the oil do not mix, and the emulsion product of the agitation of both elements, is extremely harmful in case it remains in the hydraulic system. If a certain amount of water comes in contact with the hydraulic oil, it must be removed from the hydraulic system as soon as possible.

What to do if a pump fails?

When a pump or hydraulic motor fails, the system becomes contaminated. Disassemble the unit for repair. After it has been disassembled, the tank must be emptied and cleaned to remove all traces of contamination. Lines, cylinders and valves must be washed as well. Cylinders and valves should be inspected to see if they are in good condition.

The filters must change the element; Any return line must have installed auxiliary filters of at least 25 microns, suitable to handle a maximum flow, without opening the valve that they have inside. Then the system will be started. After 40 or 50 hours of use, the auxiliary filters can be removed from the system.

This procedure, however tedious it may seem, will allow you to start the system with clean oil again, thus guaranteeing a fault-free system.