ARM 4H7932 - Caterpillar

Personal injury can result from hot oil spray.Make sure all attachments have been lowered, oil is cool and the pressure has been released from the hydraulic system before removing any components or lines.Be sure there is no pressure in the tubing before it is disconnected from the fitting.Do not allow hot oil or components to contact skin.
Start the engine and run the engine for several minutes while you actuate all hydraulic cylinders in order to circulate the hydraulic fluid.
Stop the engine and slowly loosen the hydraulic tank cap in order to release the pressure in the tank.
Lower a clear glass container into the middle of the hydraulic tank and retrieve a sample.
Hold the sample up to a light and look for any bubbles in the oil. The light will illuminate the bubbles. It is normal to have a few bubbles in the oil. Expected Result:There is an excessive number of bubbles in the hydraulic oil.Results:
No - Stop.
Yes - Proceed to test step 2.Test Step 2. Check the hydraulic system for leaks that may allow air to enter the oil. Be sure to check the following components:* Hydraulic tank oil level* Pump suction lines* Suction and return lines in the hydraulic tank - Return lines that are spraying oil - Suction lines above the oil level* Fittings and lines* Hydraulic cylindersExpected Result:A leak or a source of aeration was found.Results:
Yes - Proceed to test step 3.
No - Proceed to test step 4.Test Step 3. Remedy the problem by replacing appropriate parts, adjusting hydraulic tank lines, filling the hydraulic tank to the proper level, etc.Expected Result:Results:
Repair Complete - Stop.Test Step 4.
Make sure that the hydraulic tank has the proper level of oil.
Start the engine and actuate all hydraulic cylinders several times in order to circulate the oil. This will help to remove the air from the oil.Expected Result:Results:
Continue - If this does not resolve the problem, recheck the system. Stop.