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This instruction show you guide on how to  adjust regulator valve for JCB 3CX 4CX loader machine.

If a new regulator valve is fitted, or a valve stripped,cleaned and rebuilt, then the pressure spool should bebacked off to a low pressure. This will prevent inadvertent damage to the pump.

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Flow Regulator Spool
The pressure in the pump out line (pressure test connector B) should be 20 bar (290 lbf/in2) greater than the pressure in the load sense line (pressure test connector A). If not adjust the regulator flow spool as described below:
1 Lower the backhoe bucket and loader shovel to rest on the ground; stop the engine; operate the control levers to vent residual hydraulic pressure.
2 Gain access to the regulator valve assembly (mounted on the pump).
3 Remove cap C and loosen locknut D.
4 Turn adjusting screw E clockwise to increase pressure setting and anti-clockwise to decrease setting.
5 Repeat pressure test as detailed previously and establish valve is set correctly.
6 Tighten locknut, refit cap.



Pressure Regulator Spool
As previously explained, there is no main relief valve to control the system pressure (the pump swashplate angle will increase or decrease according to pressure demand).
 

However in situations of maximum hydraulic stall, i.e. ram full travel, the pressure in the circuit will achieve the setting of the pressure regulator spool. To adjust the setting:
1 Lower the backhoe bucket and loader shovel to rest on the ground; stop the engine; operate the control levers to vent residual hydraulic pressure.
2 Gain access to the regulator valve assembly (mounted on the pump).
3 Remove cap F and loosen locknut G.
4 Turn adjusting screw H clockwise to increase pressure setting and anti-clockwise to decrease setting.
5 Repeat pressure test as detailed previously and establish valve is set correctly.
6 Tighten locknut, refit cap.


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