Repair And Fix it

home» cylinders » how » hydraulic » test » to » How to Test Hydraulic Cylinders

---

How to Test Hydraulic Cylinders

Hydraulic cylinders can be found in a wide variety of industrial machinery. Cylinders can produce great power and are used in construction equipment, railroad machinery, manufacturing presses and in large public works facilities. The hydraulic system is normally reliable and trouble free, but over time heat and dirt wear away the close tolerances inside the moving components. Hydraulic cylinders can be very expensive and by testing a hydraulic cylinder properly you can save a lot of money in unneeded repairs.

Instructions

1

Disconnect the hydraulic hoses at the cylinder. Cap the cylinder and hoses with the correct size JIC caps and plugs. Remove the hydraulic cylinder from the equipment and place it on a work bench with the service ports facing up.

2

Remove the JIC caps from the cylinder service ports and fill both sides of the cylinder with clean hydraulic fluid. Connect one of the hydraulic pressure gauges to the service port of the blind side of the cylinder using a T-fitting. Connect the T-fitting to one of the outlet ports of the directional valve.

3

Connect a T-fitting to the service port of the piston side of the cylinder. Connect the other side of the T-fitting to the other ball valve and then to the other outlet port of the directional valve. Connect the third side of the T-connector with a short piece of hose to another T-connector. Install the hydraulic pressure gauge to one port of the last T-fitting and the other port to the pressure relief valve.

4

Connect a hydraulic hand pump to the inlet port of the directional valve following the manufacturers instructions. Open both ball valves and stroke the cylinder in each direction to remove all air from both sides of the cylinder. Position the piston rod mid-way and close the ball valve on the blind end of the cylinder.

5

Back out the adjustment on the pressure relief valve all the way. Set the directional valve to divert flow to the rod side of the cylinder. Activate the hydraulic pump and slowly turn in the pressure relief adjustment until the gauge pressure on the rod side of the cylinder equals the rated pressure of the cylinder.

6

Close the ball valve on the rod side of the cylinder and stop the hydraulic pump. Record the readings on both hydraulic gauges over time and observe any changes. Depending on the design of the cylinder, the rod side of the cylinder can be as much as twice the pressure of the blind side of the cylinder. If there are any differential pressure changes over time, then there is a problem with the piston or cylinder tube. Repair or replace the cylinder as required.