This is a copy-paste from the manual for my RX6010, same setup as 7320:
Hydraulic fluid in the implement line flows in the following order: filter (1) → pump (2) → main relief valve (6) → joystick valve (3) → remote hydraulic valve (4) → hydraulic cylinder (MLS valve)(5). If hydraulic fluid is used in a certain step, it cannot be used in the following step. For example, the remote hydraulic valve and lift cylinder cannot be used at the same time. Therefore, the remote hydraulic valve should be firstly checked if it is in neutral position if the lifting arm does not operate. Hydraulic pressure of the implement line is controlled by the main relief valve, which is installed to the joystick valve, to 185 kgf/cm² (18,130 kPa / 2,630 psi). Therefore, when pressure in the circuit rises over the relief pressure due to overload for the operation of the remote hydraulic valve, joystick valve and lifting cylinder, the relief valve is open to protect the circuit. When the engine is running at the rated speed (2,600 rpm), the primary gear pump with the capacity of 41.6 lpm is operated to supply hydraulic oil to the loader joystick valve (3), remote hydraulic valve (4), hydraulic cylinder (5), etc. mainly for tractor work. Hydraulic oil is firstly supplied to the loader joystick valve after passing through the oil filter and primary gear pump from the transmission case. When the joystick valve is operated, oil from the loader cylinder is returned to the transmission. When the joystick valve is not operated, hydraulic oil is supplied to the next component, remote hydraulic valve, through the carryover line in the joystick valve. This tractor is equipped with one double acting valve for the remote hydraulics. While the double acting valve is in use, the 3-point hydraulic cylinder, which is behind the double acting valve in the line, cannot be operated. When the double acting valve is not in use, hydraulic oil is supplied to the MLS valve through the carryover line to operate the 3-point link. When lifting the lifting arm, hydraulic oil is supplied to the lifting cylinder. When lowering or stopping the lifting arm, oil supplied to the valve and drained from the lifting cylinder is returned to the transmission case.
And for the secondary pump circuit, (Steering Pump)
The pump for the tractor operation (secondary pump) shares the oil filter (1) and suction line with the primary pump. The pump supplies oil to the steering unit (3) firstly. When the steering unit is in operation or the steering wheel is in the neutral position, hydraulic oil is supplied to the next component in order to operate other functions regardless of the steering system operation. The steering unit is equipped with the relief valve which opens to release pressure in case of load over 145 kgf/cm² in order to protect the hydraulic circuit. When hydraulic oil passes through the steering unit, it is supplied to the next component, modulator valve (4). The modulator valve supplies the PTO clutch, 4WD clutch, oil cooler(5), etc. with this hydraulic oil. The functions in the main section can be used simultaneously or separately, unlike the implement section. The sequence valve (6) shown in the circuit diagram increases the pressure where hydraulic fluid is branched to be supplied to the PTO clutch and 4WD clutch to utilize fluid supply to the PTO and 4WD. Also, if hydraulic pressure rises over 22~24 kgf/cm² by the sequence valve, the internal circuit can be damaged. The reducing valve (7) is to maintain hydraulic pressure to 17 ~ 19 kgf/cm². Hydraulic oil, flowing through the oil cooler from the modulator valve is returned to the transmission case. On the other hand, the sequence valve for the mechanical shuttle model uses spring tension and hydraulic pressure. When both 4WD and PTO are not in use, only 2 to 3 kgf/cm² of pressure is applied to the modulator, just enough to trigger the sequence valve to raise its opening pressure to 22~24 kg/cm². When either 4WD or PTO is used, hydraulic oil is supplied to the sequence valve through the pilot line (8) from the reducing valve and solenoid (PTO or 4WD), increasing pressure on the sequence valve to 22 to 24 kgf/cm² in order to supply a sufficient amount of hydraulic oil to the circuit. For this reason, the spring of the sequence valve has lower elasticity than the one of the reducing valve even though it controls higher pressure.
Hydraulic fluid in the implement line flows in the following order: filter (1) → pump (2) → main relief valve (6) → joystick valve (3) → remote hydraulic valve (4) → hydraulic cylinder (MLS valve)(5). If hydraulic fluid is used in a certain step, it cannot be used in the following step. For example, the remote hydraulic valve and lift cylinder cannot be used at the same time. Therefore, the remote hydraulic valve should be firstly checked if it is in neutral position if the lifting arm does not operate. Hydraulic pressure of the implement line is controlled by the main relief valve, which is installed to the joystick valve, to 185 kgf/cm² (18,130 kPa / 2,630 psi). Therefore, when pressure in the circuit rises over the relief pressure due to overload for the operation of the remote hydraulic valve, joystick valve and lifting cylinder, the relief valve is open to protect the circuit. When the engine is running at the rated speed (2,600 rpm), the primary gear pump with the capacity of 41.6 lpm is operated to supply hydraulic oil to the loader joystick valve (3), remote hydraulic valve (4), hydraulic cylinder (5), etc. mainly for tractor work. Hydraulic oil is firstly supplied to the loader joystick valve after passing through the oil filter and primary gear pump from the transmission case. When the joystick valve is operated, oil from the loader cylinder is returned to the transmission. When the joystick valve is not operated, hydraulic oil is supplied to the next component, remote hydraulic valve, through the carryover line in the joystick valve. This tractor is equipped with one double acting valve for the remote hydraulics. While the double acting valve is in use, the 3-point hydraulic cylinder, which is behind the double acting valve in the line, cannot be operated. When the double acting valve is not in use, hydraulic oil is supplied to the MLS valve through the carryover line to operate the 3-point link. When lifting the lifting arm, hydraulic oil is supplied to the lifting cylinder. When lowering or stopping the lifting arm, oil supplied to the valve and drained from the lifting cylinder is returned to the transmission case.
And for the secondary pump circuit, (Steering Pump)
The pump for the tractor operation (secondary pump) shares the oil filter (1) and suction line with the primary pump. The pump supplies oil to the steering unit (3) firstly. When the steering unit is in operation or the steering wheel is in the neutral position, hydraulic oil is supplied to the next component in order to operate other functions regardless of the steering system operation. The steering unit is equipped with the relief valve which opens to release pressure in case of load over 145 kgf/cm² in order to protect the hydraulic circuit. When hydraulic oil passes through the steering unit, it is supplied to the next component, modulator valve (4). The modulator valve supplies the PTO clutch, 4WD clutch, oil cooler(5), etc. with this hydraulic oil. The functions in the main section can be used simultaneously or separately, unlike the implement section. The sequence valve (6) shown in the circuit diagram increases the pressure where hydraulic fluid is branched to be supplied to the PTO clutch and 4WD clutch to utilize fluid supply to the PTO and 4WD. Also, if hydraulic pressure rises over 22~24 kgf/cm² by the sequence valve, the internal circuit can be damaged. The reducing valve (7) is to maintain hydraulic pressure to 17 ~ 19 kgf/cm². Hydraulic oil, flowing through the oil cooler from the modulator valve is returned to the transmission case. On the other hand, the sequence valve for the mechanical shuttle model uses spring tension and hydraulic pressure. When both 4WD and PTO are not in use, only 2 to 3 kgf/cm² of pressure is applied to the modulator, just enough to trigger the sequence valve to raise its opening pressure to 22~24 kg/cm². When either 4WD or PTO is used, hydraulic oil is supplied to the sequence valve through the pilot line (8) from the reducing valve and solenoid (PTO or 4WD), increasing pressure on the sequence valve to 22 to 24 kgf/cm² in order to supply a sufficient amount of hydraulic oil to the circuit. For this reason, the spring of the sequence valve has lower elasticity than the one of the reducing valve even though it controls higher pressure.
