- Backhoe Loader:
- 416E (S/N: SHA1-UP; BWC1-UP; CBD1-UP; LMS1-UP)
- 416F (S/N: KSF1-UP; LWT1-UP)
- 416F2 (S/N: LYA1-UP; HWB1-UP)
- 420E (S/N: PRA1-UP; DJL1-UP; DAN1-UP; HLS1-UP; KMW1-UP)
- 420F (S/N: LTG1-UP; LKH1-UP; JWJ1-UP; SKR1-UP)
- 420F2 IT (S/N: LYC1-UP; HWD1-UP)
- 420F2 ST (S/N: LYB1-UP; HWC1-UP)
- 422E (S/N: HBE1-UP; DSK1-UP; MAW1-UP)
- 422F (S/N: LRH1-UP)
- 422F2 (S/N: LYF1-UP)
- 427F2 (S/N: HWK1-UP)
- 428E (S/N: DXC1-UP; DPH1-UP; SNL1-UP)
- 428F (S/N: LBH1-UP; RAK1-UP; SJW1-UP)
- 428F2 (S/N: LYG1-UP; HWN1-UP)
- 430E (S/N: MXB1-UP; SWC1-UP; SCD1-UP; RLN1-UP; DDT1-UP; EAT1-UP)
- 430F (S/N: RDF1-UP; LNH1-UP; RGS1-UP; LDY1-UP)
- 430F2 IT (S/N: LYE1-UP; HWG1-UP)
- 430F2 ST (S/N: LYD1-UP; HWE1-UP)
- 432E (S/N: JBA1-UP; BXE1-UP; RXS1-UP)
- 432F (S/N: SEJ1-UP; LNR1-UP; PXR1-UP)
- 432F2 (S/N: LYJ1-UP; HWP1-UP)
- 434E (S/N: SXB1-UP; SEF1-UP; FSH1-UP; SJL1-UP)
- 434F (S/N: LDH1-UP; MTR1-UP)
- 434F2 (S/N: LYK1-UP; HWR1-UP)
- 442E (S/N: EME1-UP; PCR1-UP; GKZ1-UP)
- 444E (S/N: NBA1-UP; HXB1-UP; LBE1-UP)
- 444F (S/N: LJJ1-UP; JXR1-UP)
- 444F2 (S/N: LYL1-UP; HWS1-UP)
- 450E (S/N: EBL1-UP)
- 416F (S/N: KSF1-UP; LWT1-UP)
- Engine:
- 3512B (S/N: SRH1-UP)
Introduction
Note: This publication is a general guideline for the cleaning procedure of a hydraulic system after a pump, motor, or cylinder failure on Backhoe Loaders.
This special instruction provides the procedures for cleaning the hydraulic system of the Backhoe Loaders after a cylinder or pump failure. Performing this procedure will reduce the risk of additional system damage.
When a cylinder or pump failure is suspected, minimize usage of the machine in order to avoid further damage. The major symptoms of component failure are listed below. After you determine the component that has failed in your machine, follow the appropriate procedure in this special instruction.
The following symptoms may indicate failure of the cylinder:
- Excessive cylinder drift
- Implement cylinders respond slowly or cylinders do not move.
- Implements have low power.
- Implements have low force
The following symptoms may indicate failure of the implement pump:
- Implement cylinders respond slowly or cylinders do not move.
- Implements have low power.
- Implements have low force.
- Maximum system pressure cannot be reached.
- Unusually loud noise is heard from the piston pump.
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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the attachments have been lowered, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand. |
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| NOTICE |
|---|
Do not allow any dirt or foreign material to get into the hydraulic system during assembly, connection of lines, when components are filled with fluid, or during any maintenance operation. |
| NOTICE |
|---|
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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat products. Dispose of all fluids according to local regulations and mandates. |
General Cleaning Procedures
| Necessary Tools | ||
| Part Number | Description | Tool |
| 233-7192 | Hose Cleaner Group | A |
| 175-7546 | Oil Filter Cutter Group | B |
| 204-7392 | Media Number Filter Cart |
C |
| References | |
| Media Number | Title |
| SEBF8072 | Reuse and Salvage Guidelines "Inspection and Salvage of Hydraulic Cylinder Components" |
| SEBF8485 | Guideline for Cleaning "Cleaning Hose and Tube Assemblies Using the Hose Cleaner Groups" (1) (2) |
| SEBF8840 | Contamination Control Guidelines "Basic Principles of Kidney Loop Filtering Hydraulic Fluid Systems" |
| ( 1 ) | After cleaning, ensure that all hydraulic lines are capped using the correct cap/plug. |
| ( 2 ) | Hose cleaning tools can be found in NEHG7400 |
- If there is any internal damage to cylinder tube, follow Reuse and Salvage Guidelines, SEBF8072, "Inspection and Salvage of Hydraulic Cylinder Components" and follow this procedure. Use the hose cleaning tool with the appropriate projectiles to clean the hydraulic lines to cylinders. Follow Guideline for Cleaning, SEBF8485, "Cleaning Fluid-Carrying Hose and Tube Assemblies In Shop and Field Applications". If the cylinders are scored and exhibit evidence of internal contamination, perform the procedure in Step 2.
- Flush out the loader valve, backhoe valve, and lines. If applicable use the hose cleaning tool. If not ISO - 16/13 solvent to clean and blow dry with filtered dry air. If ride control is fitted to the machine. You will need to remove and inspect both the Ride Control Manifold Gp and the Ride Control Accumulator Gp. Replace if necessary. Remove all return lines and flush out using hose cleaning tool or if small use ISO 16/13 solvent and blow dry. After cleaning, ensure that all lines are capped using correct cap/plug. Drain off old hydraulic oil and filter, refill with clean ISO 16/13 oil and refit a new filter. Carry out the Contamination Control Guidelines, SEBF8780, "Filtration Procedure for Hydraulic Oil on D and E Series Backhoe Loaders". Ensure that the hydraulic system meets or exceeds ISO 18/15 before releasing machine.
- If any other cylinder tube is damaged, remove the respective valve`s spool and both overload relief valves. Flush out the valve and lines. If applicable use the hose cleaning tool, if not use ISO 16/13 solvent to clean/flush and blow dry with filtered air. Use ISO 16/13 solvent to clean/flush lift spool and overload relief valves and blow dry.
The cleaning of all lines should be done with Tool (A) in accordance with Guideline for Cleaning, SEBF8485.
When you cut a filter open, use Tool (B). Filters should be replaced with high efficiency filters after a cylinder failure. The high efficiency filters should be replaced at a maximum of 250 hours. Then, standard filters may be used.
Replace the oil cooler. Cleaning oil coolers is not always effective and it is difficult to know when the cleaning is complete.
Disassemble the inlet line and the outlet line of the hydraulic oil cooler. Clean the lines and the fittings.
Use clean oil when you fill the hydraulic tank or a pump. Always use clean oil when you add oil to the system. Clean oil must be at an ISO level of at least 16/13.
After you complete the procedures, take a Scheduled Oil Sample (S·O·S). Refer to Contamination Control Guidelines, SEBF8840. If cleanliness is not at the acceptable ISO level of 18/15, perform a kidney looping procedure. Use Tool (C) for kidney looping in accordance with Contamination Control Guidelines, SEBF8840.
Following A Implement Pump Failure
| Parts Required After Failure | ||
| Qty | New Part Number | Part Name |
| 1 | 126-1817 | Filter-Hydraulic (After Failure Only) |
| 1 | 245-8780 | Valve Group (After Failure Only) |
| 1 | 345-3674 | Accumulator Group (After Failure Only) |
Filters
- Drain all the system oil.
- Cut implement return filter (1) and open the filter in order to check for debris. If large debris is found, failure of the piston pump may have occurred. Refer to the section in this special instruction on pump failure
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| Illustration 1 | g02169437 |
(1) Implement return filter (2) Hydraulic oil tank (3) Hydraulic oil cooler lines (4) Hydraulic oil cooler | |
- Clean the hydraulic oil tank (2). Refer to the service manual for your machine for disassembly procedures.
Backhoe and Loader Control Lines
- Disassemble the following lines and clean the lines and the fittings:
- Inlet line (5) and output line (13) of the implement piston pump (6)
- Drain hose (16) from the case drain of the implement pump.
- Inlet line (5) and output line (13) of the implement piston pump (6)
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| Illustration 2 | g02172758 |
Implement lines (1) Implement return filter (4) Hydraulic oil tank (5) Implement pump inlet (6) Implement pump (7) Implement loader valve (8) Main loader supply line (9) Loader implement return line (10) Main pump discharge line (11) Implement backhoe valve | |
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| Illustration 3 | g02173157 |
Swing lines and cylinders (11) Implement backhoe valve (12) Swing control lines (13) Swing cylinders | |
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| Illustration 4 | g02173158 |
Control lines (14) Implement signal line (Loader) (15) Implement signal line (Backhoe) (16) Case drain (17) Flushing valve drain line | |
Oil Cooler Lines
- Replace the oil cooler (4). Cleaning oil coolers is not always effective and it is difficult to know when the cleaning is complete.
- Disassemble the inlet line (3) and the outlet line (3) of the hydraulic oil cooler. Clean the lines and the fittings.
Pumps
- Replace the implement piston pump (6) in the event of a pump failure. Refer to the service manual for your machine.
Note: Fill the case of the piston pump with oil before you connect the lines to the pump.
Initial Start
Note: The initial start procedure should be performed at an ambient temperature of at least 20 °C (68 °F).
Note: Make sure that the pump is filled with hydraulic oil. Never stall the implement during the initial start procedure.
- After the hydraulic system is cleaned and all components are reassembled, fill the hydraulic tank (4) .
- Crank the engine.
- Check the oil level in the hydraulic oil tank. If necessary, refill the tank.
- Start the engine at low idle. Allow the engine to run for several seconds. Stop the engine.
- Check the oil level in the hydraulic oil tank. If necessary, refill the tank.
- Start the engine at low idle. Allow the engine to run for several minutes. Allow the engine to run much longer in cold temperatures.
- Check the low-pressure standby. Refer to Test and Adjust, KENR8845, "Backhoe Loaders Hydraulic and Steering System".
- Listen for the sound of air in the system. Check the oil level in the hydraulic tank. If necessary, stop the engine and refill the tank.
- Slowly move the Backhoe and Loader cylinders to fully extended and retracted position several times. Do not stall the circuit.
- Move the bucket to the level position. Slowly increase engine speed to high idle.
- Check the system pressure. Refer to Test and Adjust, KENR8845, "Backhoe Loaders Hydraulic and Steering System".
- Slowly move the implement cylinders to fully extended and retracted position several times. Do not stall the implement.
- Slowly, drive the machine back and forth. Perform a few steering operations.
- Check the implement relief pressure.
- Take a Scheduled Oil Sample (S·O·S). If the oil does not meet the ISO level of at least 18/15, use Tool (C) to filter the oil until this level is reached.
The machine is now ready for operation.