WIFORA84CR

What Is A Case Drain Line ?

On most skidsteer and excavator Hydraulic systems, Hydraulic motors and pumps require a case drain line. Sometimes referred to as a third line, the case drain line will relieve any excess pressure and drain it back to your return line, then into the reservoir. Without a properly installed case drain, that extra pressure could blow a seal or damage your hydraulic line. For higher flow motors or on piston and gear motors, a case drain line is always required. Although, no matter the size of your motor, a case drain is always a good idea as it will relieve the amount of pressure on your shaft seal, helping to prolong its life. A case drain line can also increase the efficiency of your hydraulic system as it will lower the back pressure on the tank line.

Since most machines have a unique style of coupler, we do not include a coupler on our case drain line, although they are available. If your skidsteer is not equipped with a case drain, then it can be field installed.

How Important Is A Case Drain Line ?

If we say having a case drain is critical and you operate without one, you will blow out your shaft seal. Be sure to check the motor sizing charts on our website.

Exception If You Have A Hammer Valve

There is one exception in the need for a case drain on gear motors and that is if you excavator is equipped with a hammer valve, this is a larger free flow line back to tank.

Identifying Your Case Drain Line

The following galleries show a highlighted case drain line on multiple skidsteer and excavator models.