Hydraulic Actuator Service

Question 1

A method to check for internal leakage in a double acting cylinder is to stall the cylinder, remove the return line and measure the amount of oil flowing past the piston seals.

Answer 1

True

Question 2

A quick and acceptable method of removing the piston and rod assembly from the cylinder barrel is to apply compressed air to the base end of the cylinder.

Answer 2

False

Question 3

It is possible to remove the damaged chrome surface from a cylinder from a cylinder rod and replace it with new material using an electroplating process.

Answer 3

True

Question 4

Which of the following is not evidence that a hydraulic motor has failed due to lack of lubrication?
A. Heavy wear on the surfaces of moving parts/
B. Blue coloring that indicates overheating.
C. Smearing and metal transfer between contacting surfaces of moving parts.
D. Pitted erosion on motor components.

Answer 4

D. Pitted erosion on motor components.

Question 5

If cylinder hydraulic lines are reversed from their original position when the cylinder is installed:
A. Cylinder cycle times will be too slow.
B. The cylinder will not move.
C. External leakage will be a problem.
D. The cylinder will function opposite to normal operation.

Answer 5

D. The cylinder will function opposite to normal operation.

Question 6

A rough determination of cylinder rod straightness can be made by using a straight edge. A more accurate determination can be made by:

Answer 6

rotating the rod in V blocks and measuring the deflection on a dial indicator.

Question 7

In order to completely analyze a hydraulic motor failure, you must consider several contributing causes.
List 4.

Answer 7

1. Type and condition of hydraulic oil and filters.
2. Amount of time that the motor has been in service.
3. Condition of each motor part.
4. Operating conditions and symptoms before the failure.

Question 8

List 4 start up procedures that should be followed after a hydraulic motor is installed.

Answer 8

1. Back off system pressure controls.
2. Operate the motor at no load and check for leaks or unusual motor noises.
3. Apply a load to the motor and warm up the hydraulic oil. Adjust system pressure.
4. Perform operational tests.