956590 Volvo.Penta Hex. socket screw

Illustration 1 g00820077
(1) Boom priority mode (2) Swing priority mode (3) Fine control mode (4) User modeThere are four work mode switches for different implement speeds or swing speed. The switches are on the left side of the monitor panel. Only one mode can be selected at a time.
Table 1
Mode    Fine Control Solenoid Valve    Trenching Solenoid    
Boom Priority Mode     OFF
The Boom RAISE pressure switch is OFF.
ON
The Boom RAISE pressure switch is ON.     OFF    
Swing Priority Mode     OFF     ON    
Fine Control Mode     ON     OFF    
Tamping Mode     ON     OFF    
Hammer Mode     OFF
The Boom RAISE pressure switch is OFF.
ON
The Boom RAISE pressure switch is ON.     OFF    
Customer Mode     ON/OFF     ON/OFF    
Table 2
Mode    Pressure Switch    Travel Speed Solenoid Valve    
Implement Travel    Rabbit Mode    Tortoise Mode    
The Tamping Mode is NOT being used.     OFF     OFF     OFF     OFF    
ON OFF     OFF     OFF    
OFF ON     ON/OFF     OFF    
ON ON     ON/OFF     OFF    
The Tamping Mode is being used.     OFF     OFF     ON     ON    
ON OFF     ON     ON    
OFF ON     ON/OFF     OFF    
ON ON     ON/OFF     OFF    Boom Priority Mode
When the boom priority mode switch is depressed, the indicator that is located next to the switch illuminates. The boom priority mode switch is depressed for general use. When the machine is in the boom priority mode, the boom raise movement is faster. The boom priority mode is suitable for loading of trucks and for trenching.When you move the boom control lever and the pilot pressure reaches 2480 kPa (360 psi), the pressure switch for the boom RAISE pressure is turned ON.The controller activates the fine control solenoid in order to ensure that the speed of the boom is faster. The swing priority solenoid and the fine control solenoid will not be activated by any other operation of the control lever.Swing Priority Mode
When the swing priority mode switch is depressed, the indicator that is located next to the switch illuminates. The swing priority mode switch is depressed in order to place priority on the bottom pump flow to the swing motor. The swing priority mode is suitable for loading of trucks and for excavating.When the swing priority mode is selected, the swing priority solenoid is activated. The solenoid is activated in order to ensure swing priority regardless of any other operation of the control lever.Fine Control Mode
When the fine control mode switch is depressed, the indicator that is located next to the switch illuminates. The fine control mode switch is depressed in order to place priority on the top pump flow to the boom and bottom pump flow for stick in. The fine control mode is suitable for fine finish work or material handling.When the fine control mode is selected, the fine control solenoid is activated. The solenoid is activated regardless of any other operation of the control lever.During stick in operation, one pump flow drives the boom. This gives the top pump priority. During stick out operation, mixed flow from both pumps drives the stick. This delivers faster response.Engine power is limited to about 70 percent. When the engine power is limited, all of the actuators move slowly. The maximum engine speed is limited to the engine speed of position 7 of the engine speed dial.User Mode
When the user mode switch is depressed, the indicator that is located next to the switch illuminates. This mode has three submodes. The desired submode can be selected by pushing this switch repeatedly. The submode is displayed on the right side of the display. The following symbols are used: U1, U2 and U3Tamping Mode U1
When the tamping mode is selected, the hydraulic circuit is set in order to achieve smooth vertical operation of the boom.The following solenoids will also activate:
The two speed solenoid will activate
The fine control solenoidWhen the boom is lowered, the center bypass passage is not completely closed. This is true during full operation of the boom control lever. The partially open center bypass passage causes the negative flow control pressure to be greater than 0 kPa (0 psi). This limits the pump flow. The limited pump flow causes the boom to lower slowly. In addition, the machine will not raise off the ground when the bucket is lowered against the ground. When the boom is raised, the boom will move slowly due to the limited pump flow.Hammer Mode U2
Hammer mode is used in order to provide optimum pump flow to hydraulic attachments. Required pump flow must be stored in the controller before the hammer mode is used.The optimum pump flow and pressure are different among hydraulic attachments. The hammer mode is set up in the service mode. The controller calculates the power shift pressure. The controller sends the required pressure to the hydraulic system in order to obtain the required pump flow. All of the calculations are accomplished under the present engine speed.When any of the travel circuits are activated, the hammer mode is turned off.Customer Mode U3
The customer mode has several options. The options must be preset. When the mode is selected, the selected options are available. The following list of functions is available:
Boom Priority Mode
Swing Priority Mode
Fine Control Mode
Maximum Position of the Throttle Dial Setting
Maximum Hydraulic Power
Delay Time for the AEC
Engine Speed in the Second Stage of the AEC
Power Mode ON or Power Mode OFF
First Stage of the AEC or the Second Stage of the AEC
Travel Speed LOW or HIGHReference: Testing and Adjusting, "Hydraulic Hammer - Adjust"