Usage:
Introduction
Portable filter carts offer a means of removing contamination from hydraulic system fluid. Removal of contamination can be accomplished without removing and replacing the fluid from the machine.
Filter carts are an environmentally safe means of off-loading used fluid during changes, and also as a means of cleaning new fluid while replenishing the hydraulic system.
Filter carts when used in conjunction with normal hydraulic system maintenance can help prolong seal life and the life of other wearing parts as well as aiding in smooth valve and control actuation.
Most filter carts have a range of micron sizes available. Various micron size two stage filters are used for cleaning implement fluid. It is important to note that the use of filter carts does not inhibit metal producing wear on parts internal to the system nor will it remove any current mechanical problems associated with the machine hydraulics system. We recommend that filter carts be used at the appropriate filter change interval of the machine (typically 500 hours).
Should an implement such as a pump, motor, or hydraulic cylinder fail, contamination from the failure may enter the system. The filter cart can be used and the system filters replaced to help clean the implement fluid. Extreme failures may require disassembly of implements and valves to insure proper system clean-up. Fluid that has been used for more than 2000 hours or fluid that has been very hot (burned) should be changed. Use the following recommended procedures for using filter carts as an exceptionally good method to clean hydraulic implement fluid.
Reference: Operation and Maintenance Manual; Special Instruction, form SEHS9043.
Procedure
Typical oil leaks.
1. Inspect all implements for leaks and repair if necessary.
Seal leakage on hydraulic cylinders not only allows fluid to escape, it may allow contamination to enter the system causing internal wear to cylinder, pump, and valve parts. Hoses, valves, drive motors, and system connections should be inspected closely for leaks.
2. Start the machine and actuate the hydraulic implements to bring the hydraulic system to operating temperature. Take a sample of the implement fluid for analysis.
It is important to determine the contamination level (base line) in a system prior to using the filter cart. Taking samples prior to and after filtering establishes the types and amount of contaminants present and also the effectiveness of the filter cart in removing the contaminants.
NOTE: Particle count is the recommended detection method for determining contamination levels and size.
Always take samples before and after using the filter cart. Oil sample bottles are available through your Caterpillar dealer. Procedures used to extract the sample are available in publication PEHP6001. For hydraulic systems that do not have sampling ports for taking samples use Special Instruction SEHS9043 for the procedure to install sampling ports on the machine.
3. Replace system implement fluid filters.
Refer to the Operation and Maintenance Manual for your machine for the correct procedure to use.
Portable filter cart.
4. Attach portable filter cart to machine.
When possible, connect to the ecology drain valve. The ecology drain valve is located on the bottom of the hydraulic tank.
Ecology valve.
Connect the filter cart pump suction hose. Typically this drain valve requires a 25.4 mm (1.00") pipe be threaded in far enough to open the spring loaded valve.
Remove the fill cap and fill strainer from the top of the tank. Store the strainer and cap in a clean place to avoid contamination and possible damage.
Insert the discharge line from the filter cart into the tank far enough to completely submerge the end of the line.
NOTE: To prevent splashing out of the tank during the cleaning process, a fill cap can be modified by drilling a hole large enough to install a length of 25.4 mm (1.00") pipe through the cap to the proper submerged level. Secure the properly located pipe to the cap by tack welding.
Suction and discharge lines must be inserted through the fill neck of the tank should access to the ecology drain valve not be possible.
5. Turn the filter cart on. Occasionally the filter cart pump will cavitate during start up. Cavitation occurs due to air in the suction line and pump. If cavitation continues for more than a minute, shut the cart off and purge the air from the lines before restarting.
After the cart runs for a few minutes check the element indicator on the outlet filter.
Filter element indicator.
If the cart filters indicate a dirty condition, shut the filter cart off and replace the filters. Restart the cart and continue to filter the system.
6. Start the machine.
Position the throttle on Medium Idle. Actuate the system implements for the time periods recommended by the filter cart manufacturer to achieve specified cleanliness levels. Typically for a 189.50 L (50 gal) reservoir, the machine should be exercised for about one hour to achieve a high level cleanliness.
Actuating the implements during the cleaning process keeps small particle contaminants in suspension and assures better cleaning of the fluid.
If it is not possible to operate the implements with the filter cart attached, disconnect the cart, run the machine for approximately fifteen minutes, reconnect the cart and run the cart for thirty minutes. Repeat the machine off cycle three times. Make sure that all the fluid in the hydraulic system has been circulated through the filter cart.
7. Disconnect the filter cart from the machine. Replace the ecology drain valve plug. Install the screen in the fill neck of the tank.
Check the fluid level. Maintain the level to the proper level as established in the Operation and Maintenance Manual for your machine.
NOTE: The correct type of fluid is specified in the Maintenance Specification section of the Operation and Maintenance Manual for your machine.
Inspect the fill cap gasket and replace if necessary. Install the fill cap.
8. Take a sample of the filtered fluid.
Use the appropriate sampling procedures and remove a fluid sample for comparative analysis with the sample taken prior to the cleaning of the system. Retain a record of the particle count analysis for future reference.