How to Drain Hydraulic Systems Completely

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One way to get efficient service from hydraulic equipment is to ensure that old hydraulic fluid is fully drained from the system before fresh fluid is added. However, not many DIY operators of rented hydraulic equipment, such as excavators, know how to drain the system completely. This article discusses some tips that you can implement in order to drain old hydraulic fluid from the construction equipment that you have rented.

Close All Cylinders

Some construction equipment, such as heavy-duty excavators, may have more than one hydraulic cylinder. The best way to drain such a system fully is to close all those cylinders so that all the fluid can be ejected from the drain port. The equipment that you rented may have controls that you can use to close the hydraulic cylinders. If not, check around each hydraulic cylinder and you may see a valve that you can push into the close position in order to prevent fluid from remaining inside an open cylinder. 

Open All Drain Ports

It may be possible to drain most of the hydraulic fluid from the different cylinders by opening the main drain port. However, better results can be obtained when you open all the drain ports in the hydraulic system. You should therefore check underneath each cylinder and locate the drain ports located there so that you open them all.

Allow Air Into the System

Air creates pressure that can help to eject all the oil from the hydraulic cylinder of that equipment. Some people hesitate to open the breather ports for fear that contaminants will get into the system. You can prevent contaminants from entering the system by placing desiccant breathers on each of the breather ports on the cylinders. The air that gets in will help all the degraded hydraulic fluid to drain out so that you can refill the system with fresh fluid.

Pull All Filters

Hydraulic systems usually have return line filters that trap any contaminants that could have entered the system. However, those return line filters can also trap some hydraulic fluid within them. It is therefore advisable to remove the filters so that the fluid that they contain does not remain within the system when you purge the old fluid.

The hydraulic cylinders of the rental equipment will be less likely to suffer any failure if you ensure that the system is well drained before you replace the old fluid with new fluid. Contact hydraulic cylinder experts for help in case you notice any abnormality within the system as you change out the fluid.