1-Accumulator
2-Delivery connection
3-Pump housing
4-Refill reservoir
5-Cylinder lining

6-Cylinder head
7-Suction connection
8-Eccentric shaft
9-Ball bearing

10-Needle bearing
11-Suction pin
12-Drive rod
13-Piston

14-Piston seal
15-Diaphragm
16-Centering disk
17-Nut

IMPORTANT: The pump speed must not exceed 540 rpm.

The 700 series trailed sprayer can be equipped with a single piston diaphragm pump with a maximum capacity of 280 liters per minute at 540 rpm. The pump is located on the frame and is driven by the tractor

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IMPORTANT: If the pump is started at a high speed, the superfluous oil cannot escape quickly enough. The diaphragms will then make too large a stroke while there is no counter pressure from the liquid yet. This may force the diaphragm, possibly resulting in premature diaphragm damage or oil leaks where the diaphragm (D) is attached to the piston.

When the pump is idling (A), the space between the pistons and the diaphragms will fill with oil from the refill reservoir on the pump. When the pump is subsequently activated and the diaphragms are directly subjected to counter pressure from the liquid, the diaphragms will be pressed against the piston. This will press the superfluous oil back into the refill reservoir. The larger the length of piston stroke and diaphragm diameter, the greater the amount of oil displaced. This displacement of oil may take some time, depending on the temperature of the oil. The pressure on the diaphragm will be increased considerably while this superfluous oil is being displaced into the refill reservoir.

After a few revolutions, the diaphragm lies completely against the piston (C).

A-Oil level upon standstill
B-Oil level upon starting
C-Oil level during work
D-Diaphragm attaching point

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• Always check the oil level before operation of the pump. The oil level in the reservoir (A) needs to be between the minimum and maximum level indices. Repeat the level check with the pump in operation. The amount of oil may decrease after the first hours of operation due to deformation of the diaphragms in contact with the chemical product (causing more oil to be used). Also see section "Maintenance".
• Priming of the pump needs to be done with the master shut-off valve closed (no pressure).
• Always start the pump at the lowest possible speed of the tractor (stationary).
• When the pump has been inactive (for a long time), always rotate the pump shaft a few turns by hand before starting the pump, until the superfluous oil between the pistons and diaphragms has been pressed into the refill reservoir and the pump has been filled with liquid.
• Filling via the pump: Always begin filling at low speed until the pump is fully filled with liquid and the liquid flows into the tank. Only increase the pump speed after the pump is completely filled. Never fill at a speed exceeding 540 rpm. In the case of extra long filling hoses (more than 6 meters) and/or a lift higher than 250 cm, the PTO speed must be reduced to approx. 475 rpm.
• In event of breakage of a diaphragm, the oil changes color and turns white. In this case, the pump needs to be stopped immediately and the diaphragms need to be replaced by your John Deere dealer. There are two different types of diaphragms available: Standard black diaphragms Nitril (WZ3023051) which can also be ordered as a complete set (WZ2202034), and white Desmopan diaphragms (WZ3023026) for corrosive chemicals. Due to the hardness of the diaphragms, the wear will be increased.

A-Pump oil reservoir

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The piston diaphragm pumps are fitted standard with a pressure accumulator (B), which ensures a regular flow of liquid, by evening out the pressure pulses.

The recommended air pressure is depending upon the spraying pressure (see table below).

The pressure in the accumulator can be measured and corrected via valve (A) located on the pressure accumulator.

NOTE: The pre-pressure should be checked with the machine turned off.

Check the valve for leakage. The needle on the pressure gauge must be more or less motionless during spraying.

A-Pressure control valve
B-Pressure accumulator

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