POPPET 2U0270 - Caterpillar

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Open the access door on the right side of the machine.
Clean the pump. Clean the hydraulic lines. Clean the hydraulic tank.
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Remove the plug from the tube. Allow the oil to drain into a container.
Inspect the O-ring. Replace the O-ring if wear or damage is evident.
Clean the plug. Install the plug and the O-ring into the drain port.
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(4) Bolt (5) Washers (6) Cover (7) Spring (8) Screen
Remove bolts (4) , washers (5) , and cover (6) .Note: Used filters and used fluids should always be disposed of according to established local regulations.Note: Do not allow spring (7) to fall into the tank.
Remove spring (7) and screen (8) .Note: Refer to Operation and Maintenance Manual, "General Hazard Information" for information on Containing Fluid Spillage.
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(9) O-ring seal (10) O-ring seal
Remove O-ring seal (9) from the old screen.
Inspect O-ring seal (9) and O-ring seal (10) . Replace the O-ring seals if wear or damage is evident.
Install O-ring seal (9) on new screen (8) .
Install screen (8) and spring (7) . Then, install cover (6) , washers (5) , and bolts (4) .Note: Make sure that the O-ring seals and the spring are properly positioned during installation.Note: Perform the following five steps only if your machine is equipped with an auxiliary gear pump.
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(11) Bolts (12) Washers (13) Plate
Remove four bolts (11) and four washers (12) .
Pull plate (13) away from the hydraulic tank. Inspect the seal on plate (13) . Replace the seal if wear or damage is evident.
Remove the screen.Note: Used filters and used fluids should always be disposed of according to established local regulations.
Install a new screen.
Install four bolts (11) and four washers (12) in order to attach plate (13) to the hydraulic tank.
Fill the hydraulic system oil tank. Refer to Operation and Maintenance Manual, "Refill Capacities" .
Inspect the O-ring on the filler plug for damage. Replace the O-ring, if necessary. Clean the filler plug. Install the filler plug.
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Remove the pressure cap.
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Inspect the pressure cap. Clean the pressure cap. Replace the pressure cap if damage is evident.
Install the pressure cap.
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Note: Make no attempt to start the engine until the pump has been filled with hydraulic oil. Serious damage to the hydraulic components can result.
When the hydraulic oil has been replaced,the air must be removed from the hydraulic oil system. Use the following procedure to remove the air from the hydraulic oil system.
While the engine is stopped, remove the vent plug which is on the top of the pump. Do not install the vent plug until the pump is filled with hydraulic oil. After the pump is filled with hydraulic oil, tighten the vent plug. Start the engine. When the engine is at low idle, fully raise the boom. Hold the boom in this position.
Stop the engine. Slowly lower the boom until the bucket is on the ground. This pressurizes the hydraulic tank.
Slowly loosen the vent plug for several turns until the hydraulic