Section 2-2 - Care and Safety General Procedures Venting the Hydraulic Pressure
Venting the Hydraulic Pressure
!MWARNING
4
Hydraulic Pressure Hydraulic fluid at system pressure can injure you. Before disconnecting or connecting hydraulic hoses or couplings, vent the pressure trapped in the hoses in accordance with the instructions given in this publication.
Clean the top of the tank around the filler cap B.
!MCAUTION Allow the hydraulic fluid temperature to cool before removing the hydraulic tank filler cap. Open the cap slowly to prevent oil being forced out of the filler neck. 5-3-4-8
HYD-1-5
!MCAUTION
Important: This procedure is only to be used before disconnecting hydraulic hoses. Before removing other hydraulic components refer to the correct Removal procedure.
Do not run the engine with the hydraulic tank filler cap removed.
1
Make the machine safe with the boom lowered. Refer to Prepare the Machine for Maintenance.
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2
Operate the controls to remove the hydraulic pressure from the service hose lines. a
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Slowly remove filler cap B to allow the system to vent fully and prevent oil being forced out of the filler neck.
550-80 machines - turn the starter key to the ON position.
Important: Until the hydraulic pressure is fully released the boom lower and retract service are still operative when the engine is not running. Make sure that the boom is lowered or supported fully on the safety strut. K Parking the Machine and Making it Safe ( T 2-2-3) Operate the boom raise/lower hydraulic services until the pressure is released.
A710870-5
Fig 3. Machines with External Sight Gauge
b Manually operated hydraulic services - operate the controls of the service to be disconnected. c
Electrical and servo operated hydraulic services turn the starter key to the ON position. Operate the controls of the service to be disconnected.
Important: To release the hydraulic pressure from the 550-80 machines and electrical/servo operated services the battery must be connected while you operate the controls. 3
If necessary, open rear cover A to get access to the filler cap B. Refer to Section 3 - Access Panels, Rear Cover (if fitted).
2-2-6
732370-5
Fig 4. Machines without External Sight Gauge
9813/0900-2 (2-02-05)
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