- Caterpillar Products: All
Important Safety Information
European Union Compliant, CE marked
Most accidents that involve product operation, maintenance, and repair are caused by failure to observe basic safety rules or precautions. An accident can often be avoided by recognizing potentially hazardous situations before an accident occurs. A person must be alert to potential hazards. This person should also have the necessary training, skills, and tools to perform these functions properly.
Improper operation, lubrication, maintenance, or repair of this product can be dangerous and could result in injury or death.
Do not operate or perform any lubrication, maintenance, or repair on this product until you have read and understood the Tool Operating Manual.
Safety precautions and warnings are provided in this manual and on the product. If these hazard warnings are not heeded, bodily injury or death could occur to you or to other persons.
The hazards are identified by the "Safety Alert Symbol" and followed by a "Signal Word" such as "DANGER", "WARNING", or "CAUTION". The Safety Alert "WARNING" label is shown below.
A non-exhaustive list of operations that may cause product damage are identified by "NOTICE" labels on the product and in this publication.
Caterpillar cannot anticipate every possible circumstance that might involve a potential hazard. The warnings in this publication and on the product are, therefore, not all inclusive. If a tool, procedure, work method, or operating technique that is not recommended by Caterpillar is used, the operator must be sure that the procedures are safe. The operator must also be sure that the product will not be damaged or made unsafe by any unspecified procedures.
The information, specifications, and illustrations in this publication are based on information that was available at the time that the publication was written. The specifications, torques, pressures, measurements, adjustments, illustrations, and other items can change at any time. These changes can affect the service that is given to the product. Obtain the complete and most current information before you start any job.
When replacement parts are required for this product Caterpillar recommends using Caterpillar replacement parts or parts with equivalent specifications including, but not limited to, physical dimensions, type, strength, and material.
This manual contains safety information, operation instructions and maintenance information and should be stored with the tool group
Some photographs or illustrations in this publication may show details that can be different from your service tool. Guards and covers might have been removed for illustrative purposes.
Continuing improvement and advancement of product design might have caused changes to your service tool, which are not included in this publication.
Whenever a question arises regarding your service tool or this publication, consult Dealer Service Tools (DST) for the latest available information.
The Safety section lists basic safety precautions.
Read and understand the basic precautions listed in the Safety section before operating or performing maintenance and repair on this service tool.
General Information Section
The General Information section describes tooling functions and features. The section provides useful information on individual parts, additional tooling, and resources.
The Operation section is a reference for the new operator and a refresher for the experienced operator.
Photographs and illustrations guide the operator through correct procedures for using the tool group.
Operating techniques outlined in this publication are basic. Skill and techniques develop as the operator gains knowledge of the service tool and the tools capabilities.
The Maintenance section is a guide to tool inspection, cleaning, storage, and tool disposal
Service Parts Section
The Service Parts section is a reference for parts identification and available part numbers.
Safety Icon Nomenclature
Personal Protection/Important Information
Personal Protection/Important Information
|Crushing hazard (foot)|
|Crushing hazard (hand)|
|Electrical Shock - Hazard|
At operating temperature, the hydraulic tank is hot and under pressure.
Hot oil and components can cause personal injury. Do not allow hot oil or components to contact skin.
Remove the filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. Remove the filler cap slowly in order to relieve pressure.
Personal injury or death can result from escaping fluid under pressure.
Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury.
Always use a board or cardboard when checking for a leak.
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.
Refer to Special Publication, NENG2500, "Caterpillar Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Caterpillar products.
Dispose of all fluids according to local regulations and mandates.
To prevent dirt and contaminants from entering the hydraulic system, always plug or cap the lines, fittings, or hoses as they are disconnected.
This action also lessens the chance of oil spills.
General Information Section
This Tool Operating Manual contains information on how to use the 9U-5971 or 173-9842 Filter Cart Group to clean a machines hydraulic oil. The cart is connected into either the high-pressure outlet lines from the pump or to the low-pressure return lines leading from the main control valve. The filter cart does not have a pump and depends on the flow from the machines implement pump to filter oil.
Use filter carts only to remove micron-size particles of contamination from a maintained and operating hydraulic system. Carts will remove finer particles than the particles normally filtered out with the machines filters. If the machine has experienced a major, metal generating failure, consider completely disassembling and cleaning all components before attempting a filtering procedure.
The use of high-pressure oil filters allows the cart to filter oil in all types of hydraulic systems. The cart is equipped with 41000 kPa (5946.6 psi) fittings (screw-to-connect) and special XT-5 hose couplings (external, straight thread, O-ring). Couplings are designed for either 25 mm or 32 mm (0.98 inch or 1.26 inch) inside diameter XT-5 hose. Refer to the ""Parts for High-Pressure Hose Assemblies" " Section or Special Instruction, NEHG3598, "Tool Announcement" and Tool Announcement, NEHG3786, "Tool Announcement" for a list of compatible connectors and adapters.
Special Instruction, NEHG3598, "Tool Announcement"
Special Instruction, NEHG3786, "Tool Announcement"
Special Instruction, NEHG3961, "Tool Announcement ( 9U-6662 Portable Contamination Monitor Group "
Special Instruction, NEHS0580, "Tool Operating Manual 9U-6662 Portable Contamination Monitor Group "
Special Instruction, PECP3301, "Caterpillar Hose and Coupling Reference Guide"
Special Instruction, NENG2500, "Service Technology Tool and Shop Products Guide"
Special Instruction, SEHS9043, "Special Instruction for Installation of Scheduled Oil Sampling Valve"
Additional Contact Information
For additional product support questions concerning this tool, contact the Dealer Service Tools Hotline at:USA: 1-800-542-8665, Option 1International: 1-309-578-7372
Filtering Heavily Contaminated Oil
Attempting to filter excessively contaminated oil may damage the machines implement pumps or other hydraulic components.
If the oil is heavily contaminated, possibly the result of a major component failure, DO NOT use the cart to filter the oil.
When oil is heavily contaminated, the possibility of damage to the implement pump as oil is pumped through the filter cart increases. In cases of heavy contamination, the oil should be filtered using a 127-8781 or 169-7159 Filter Cart or a similar product. Attempting to filter excessively contaminated oil may damage the machines implement pump or other hydraulic components. If a hydraulic component has failed, reccomendation is that the hydraulic tank and lines be drained, cleaned, and refilled with new "clean" or finely filtered oil before using the carts.
Determining Oil Cleanliness
- Establish a "baseline" level of oil cleanliness by taking an initial particle count from the machine.
- Use the "particle counting" procedure to determine the level of oil cleanliness.
Note: The particle count procedure electronically measures the size and quantity of microscopic particles in an oil sample to determine if the sample is "clean" or "dirty".
- Compare the initial particle count readings to readings taken after a failure or whenever a concern exists about possible debris in the hydraulic system.
There are two types of particles counts: laboratory and field.
Laboratory Particle Count
Cat dealers offer laboratory particle counting as part of the S·O·S fluids analysis program. Submit an oil sample from a repaired hydraulic system to the Cat dealer. A sample establishes a baseline level of oil cleanliness and provides a basis for future comparison.
Note: For more complete explanation of particle counting, refer to Product Bulletin, PEJT5025, Scheduled Oil Sampling.
Field Particle Count
A field particle count device can be used to determine if the repaired hydraulic system has been properly cleaned before placing the machine back into service. Caterpillar offers the 9U-6661 Particle Counter for field use, which is part of 9U-6662 Particle Counter Contamination Group .
Note: The 9U-6662 Particle Counter Contamination Group can only be used with pressurized hydraulic systems. Refer to Special Instruction, NEHG3961, "Tool Announcement ( 9U-6662 Portable Contamination Monitor Group " Special Instruction, NEHS0580, "Tool Operating Manual 9U-6662 Portable Contamination Monitor Group " for additional information.
An oil sample should also be submitted to the Cat dealer S·O·S laboratory.
ISO Standards for Cleanliness
The particle count test does two things.
- Gives an actual count of particles greater than 5, 15, 25, and 50 microns in size.
- Creates a two-position International Standards Organization (ISO) number to reference particle quantity and size.
International Standards Organization (ISO) Number. (Example: 21/17)
- The first number refers to particles larger than 5 microns in size.
- The second number refers to particles larger than 15 microns in size.
Note: A micron is 1/1,000,000th of a meter.
Example: A 100 mL (3.4 oz) hydraulic oil sample has a particle count reading of 21/17 (Refer to Table 1).
- Contamination by particles larger than 5 microns is between 10,000 and 20,000 particles per 1 mL (0.034 oz) or 1,000,000 and 2,000,000 particles per 100 mL (3.4 oz).
- Contamination by particles larger than 15 microns is between 640 and 1300 particles per 1 mL (0.034 oz) or 64,000 and 130,000 per 100 mL (3.4 oz)
Note: The contamination level will decrease as the ISO range decreases, indicating the oil is becoming cleaner.
|ISO 4406 Contamination Specifications    |
|Particle Count per ml    ||Range
|More Than    ||Up to and Including    |
|80,000    ||160,000    ||24    |
|40,000    ||80,000    ||23    |
|20,000    ||40,000    ||22    |
|10,000    ||20,000    ||21    |
|5,000    ||10,000    ||20    |
|2,500    ||5,000    ||19    |
|1,300    ||2,500    ||18    |
|640    ||1,300    ||17    |
|320    ||640    ||16    |
|160    ||320    ||15    |
|80    ||160    ||14    |
|40    ||80    ||13    |
|20    ||40    ||12    |
|10    ||20    ||11    |
|5    ||10    ||10    |
|2.5    ||5    ||9    |
|1.3    ||2.5    ||8    |
|0.64    ||1.3    ||7    |
|0.32    ||0.64    ||6    |
|0.16    ||0.32    ||5    |
|0.08    ||0.16    ||4    |
|0.04    ||0.08    ||3    |
|0.02    ||0.04    ||2    |
|0.01    ||0.02    ||1    |
Hookup and Installation
Refer to Table 3, "Parts for High Pressure Hose Assemblies" for a list of adapters, seals, and hose couplings that can be used to connect the filter cart into the machines hydraulic system.
The filter can be connected to a machine during maintenance or mounted on a machine being placed back into operation. Filter carts that filter oil while the machine is in operation will remove contaminants faster from the hydraulic system. Filter carts attached to stationary machines remove contaminates more slowly because the oil is trapped in the implements and hydraulic lines.
There are three separate filtering systems on the filter cart. Two of the filters are high-pressure filters which can filter oil directly from the pump. The third filter is a low-pressure filter which filters oil returning to the tank.
High-Pressure Filters (Inlets and Outlets)
The filter is designed to route the oil through the filter correctly, no matter which side the inlet is connected.
Connect the inlet line to the port marked "IN" and the outlet line to the port marked "OUT".
- To keep from further contaminating the system, use a high-pressure washer and compressed air to clean away any dirt or debris buildup. Thoroughly clean around the hose connections at the implement hydraulic pumps, the main control valves, and the filter and screen covers on the hydraulic tank.
- Position the machine in an open area so the implements can be cycled without having to move the machine. For excavators, swivel the upper frame so the bottom of the hydraulic tank can be accessed between the tracks.
- Use 4C-9475, 9U-7361, or 9U-7362 Transfer Cart , to drain the hydraulic tank into a suitable container. A 9U-7533 Fluid Vacuum or 9U-7534 Fluid Recovery Unit can also be used to store the fluid.
- Remove, clean, and reinstall the suction screen in the bottom of the hydraulic tank. Remove, clean, and reinstall the pipe assemblies and the hoses that connect the hydraulic tank to the pump.
- Connect the filter cart to the machine using the pump supply and return lines.
- For low-pressure filtering, use adapter blocks, refer to Table 3, to connect the return lines from the main control valve to fabricated hoses from the low-pressure filter on the 9U-5971 and 173-9842 Filter Cart .
- For high-pressure filtering, remove, cap, and set aside the existing pump supply hoses. Fabricate all new hoses to connect the high-pressure filters on the filter cart into the machines hydraulic system. Refer to Table 3 for a list of parts to make the new hose assemblies.
Note: If the oil is filtered from the pump supply side, an extra set of hoses may be necessary. Some machines, such as excavator pumps, have two outlet ports and hoses leading to the main control valve.
- Replace the standard machine filter elements with high-efficiency elements listed in Table 2.
Table 2 Hydraulic/Powertrain Filter Comparison List     Size in
Standard Filter Element Part Number     Abs.
High-Eff. Filter Element Part Number     Abs.
(3x9)     1R-0728     35 to 40     4T-31302     13     (4x9)     1R-0719     4T-31312 (5x9)     1R-0741     4T-31322 (7x9)     7J-0670     4T-31332 (5x11)     1R-0722     4T-3134 10     (5x7)     1R-0735     104-6931 (3.5x5.5)     1R-0746     - (4x9)     1R-0719     9W-29323 6     (5x9)     1R-0741     9W-29334 152x3005     094-3229     5I-45304 152x4005     094-4412     4I-95134 1Absolute micron rating (Beta x = 75% or 98.7% efficient).
2 For Water glycol fire-retardant fluid (also for Hystat HPCU).
3For manufacturing use (TTT transmission roll-off cleanliness).
4E-model and 300 Family HEX (used in singles and multiples).
5Sizes are measured in millimeters.
- Refill the hydraulic oil tank with clean filtered hydraulic oil as specified in the Service Manuals, Lubrication, and Maintenance module.
- Connect the 9U-6660 Particle Counter to an appropriate test port. Refer to the Special Instruction, NEHS0580, "Tool Operating Manual 9U-6662 Port Contamination Monitor Group " for additional information on how to use the counter.
- Purge all of the trapped air out of the hydraulic system. Because hydraulic lines have been disconnected and oil will have drained from various components, air is likely to be in the system. Refer to the startup instructions in the Operation and Maintenance Manual of the machine being serviced for information on purging the air from the system.
Make sure that all trapped air is removed from the hydraulic system. Never start the machines hydraulic pump until pump has been filled with oil. Either of these conditions can damage the pump and other hydraulic components.
- Make sure all lines and hoses are correctly connected and all connections are tight.
Typical Filter Cart Installation on 325HE Excavator
- Start the machine and operate the engine at low idle. Check and make sure that none of the hose coupling and/or filter cart connections are leaking. If the cart is mounted onto the vehicle, securely fastened to the machine.
- Actuate the hydraulic implements to bring the hydraulic system and oil up to operating temperature. Any remaining contamination in the oil will be placed in suspension.
- Perform a particle count test to establish a baseline contamination level.
- If the hydraulic oil is being cleaned with the machine in a stationary position, put the throttle at medium idle, and operate the implements for 5 to 10 times repeatedly.
Note: Do not operate the travel circuits, unless the filter cart is mounted to the machines frame.
- Continue to actuate the implements during the filtering process. Actuation keeps the contaminants in suspension and causes the oil in remote lines, cylinders, motors, and valves to go back to the cart for filtering.
- Perform a particle count test and compare the results to previous tests. Refer to the ""Oil Cleanliness" " Section for additional information. If the hydraulic system is being filtered while the machine is operating (mobile), perform particle count analysis after 1 hour of operating time. Compare the results to previous tests.
- Continue filtering the oil and taking particle count checks until the range number has decreased by one number (refer to Table 1). Because of the differences between machine hydraulic systems, a time estimate for oil cleanup is not possible.
"Dirty Filter " Indicator
Note: The filter carts are equipped with "Dirty Filter " indicators that must be periodically checked as the filter cart operates. Replace the filter elements whenever the indicators show filters are dirty or plugged. When the filter elements on the filter cart are changed, the return filter in the machines hydraulic tank should also be changed.
Parts for High-Pressure Hose Assemblies
|Parts for High-Pressure Hose Assemblies    |
|Part No.    ||Desc.    ||Specification    |
| Threaded Adapter -
41340 kPa (6000.0 psi)
|4C-5088    ||Coupling    ||1 NPTF internal thread x 1 5/8-12 STOR external thread    |
|4C-5087    ||1 5/8-12 STOR x 1 5/8-12 STOR|
|4C-5091    ||1 5/16-12 STOR external thread x M30 x 2 external thread|
|4C-5090    ||1 5/16-12 STOR external thread x M30 x 2 internal thread swivel|
|4C-5089    ||1 5/16-12 STOR external thread x 1 3/16-12 ORFS internal thread 90 degree swivel|
|4C-5092    ||1 5/16-12 STOR internal thread x 1 5/8-12 STOR external thread|
|Hose End Fittings    |
|1.00 XT-5 Hose (1 5/16-12 STOR external thread) used with 5P-0477 Sleeve    |
|4C-6461    ||1.25 XT-5 Hose (1 5/8-12 STOR external thread) used with 5P-0477 Sleeve|
|4C-6462    ||1.25 XT-5 Hose (1 5/16-12 STOR external thread) used with 5P-0477 Sleeve|
|Quick Disconnect Couplers and Nipples    |
|9U-5076    ||QD Coupler Nipple    ||3/4-12 internal thread    |
|9U-5075    ||3/4-12 external thread|
|4C-6481    ||1-12 internal thread|
|4C-6482    ||1-12 external thread|
|4C-5094    ||1 1/4-12 internal thread|
|4C-5093    ||1 1/4-12 external thread|
|Hydraulic Test Adapters    |
|9U-5934    ||Adapter    ||1.00 Hose    |
|9U-5936    ||1.25 Hose|
|9U-5935    ||1.50 Hose|
|9U-5273    ||1.00 Flange|
|9U-5272    ||1.25 Flange|
|9U-5274    ||1.50 Flange|
|O-ring Face Seal Adapters (STOR Thread Size - ORFS Thread Size    |
|8T-3611    ||Adapter    ||1 5/8-12 - 1 11/16-12    |
|6V-9875    ||1 5/8-12 - 1 7/16-12|
|6V-8635    ||1 5/16-12 - 1 7/16-12|
|8T-8898    ||1 5/16-12 - 1 7/16-12|
|8T-0198    ||1 5/16-12 - 1 7/16-12|
|6V-8716    ||1 5/16-12 - 1 3/16-12|
|8T-0197    ||1 5/16-12 - 1 3/16-12|
STOR - Straight Thread O-ring
ORFS - O-ring Face Seal
QD - Quick Disconnect
NOTE: All dimensions are in inches, except where otherwise noted.