COUPLING 7N2550 - Caterpillar

Test Preparation
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Install the steering frame lock in the LOCKED position.
Start the engine. Operate the engine at high idle. Continuously stall the RACK BACK function while simultaneously raising the lift arms at full speed. When the lift arms are almost raised, cycle the tilt cylinder almost to the FULL DUMP position. Then move the tilt cylinders to the full RACK BACK position. Continuously stall the RACK BACK function and simultaneously lower the lift arms back to the ground level position. Without stalling the RACK BACK function, cycle the lift function to raise the lift arms fully. Then lower the lift arms in order to allow the pump to operate at low-pressure briefly and circulate oil through the system. Repeat this process in order to increase the temperature of the oil to normal operating temperature.
Operate the machine for a few minutes before you obtain the oil sample. This step will thoroughly mix the oil for a more accurate sample.
Lower the work tool to the ground.
Turn the engine start switch to the OFF position.
Turn the key start switch to the ON position. Move all control levers, brake pedals, and steering wheel through all positions in order to release any pressure in the hydraulic system.
Slowly remove the hydraulic tank cap In order to release the pressure in the hydraulic tank. Reference: For additional information about the release of hydraulic oil pressure, refer to Testing and Adjusting, "System Pressure - Release" for the machine that is being serviced.
Ensure that the control levers are in the HOLD and FLOAT positions. Test Procedure
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Location of the Oil Sampling Port on the left rear of the machine
(1) Oil Sampling Port
Note: Only perform a bottle sample when the system pressures are below 3450 kPa (500 psi). Prepare all equipment used to sample oil and protect the equipment from contamination.
The oil sampling port (1) is located on the left side of the machine. Reference: Refer to Special Publication, PEHP6001, "How To Take A Good Oil Sample" for more information about obtaining an oil sample.
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Sample bottle package
Open the 169-8373 Sample Bottle package. Remove the sampling probe tube from the bag.
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Probe holder and probe
Insert the open sampling probe tube into and through the 162-8873 Sample Bottle Probe Holder counter bored end. Pull the probe tube all the way through the holder until the sampling needle seats in the holder.
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Remove the sampling bottle from the package. Install the cap with two holes onto the bottle. Install the probe tube into one of the holes in the cap.
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Return the assembled bottle and return the probe back into the package in order to prevent contamination.
Exercise the machine until the system oil to be sampled is up to normal operating temperature or at a minimum of 50 °C (120 °F).
Park the machine on level ground. Lower all the attachments. Engage the parking brake.
Set the engine at low idle. Make sure that all systems are in safe positions. Refer to the Operation and Maintenance Manual.
Remove the dust cover