Pulse Width Modulated (PWM) Valve Flow Test 1. Make sure hydraulic oil is at normal operating temperature by operating the machine for approximately 10 minutes. Make sure the hydraulic tank is full. 2. Park machine on a level surface, stop engine, engage parking brake, and remove key from the ignition switch. After turning engine off, operate all hydraulic controls to relieve hydraulic system pressure. 3. Perform the Gear Pump Flow Test. Make sure that spray motor circuit hydraulic flow has been tested and recorded.
CAUTION
10.Using the application rate switch, increase the spray rate slightly while monitoring the flow tester. Check for hydraulic leakage and correct before proceeding with test. 11. With the engine still running at high idle, increase the spray rate with the application rate switch while monitoring the flow tester. As the spray rate is increased, hydraulic flow should increase as well. At maximum spray rate, hydraulic flow on the tester should approach spray motor circuit hydraulic flow previously tested and recorded. If hydraulic flow does not increase correctly, either the the circuit wiring to the PWM Valve solenoid or the PWM Valve is faulty. 12.Disconnect tester from PWM Valve CF port fitting and hydraulic hose. Reconnect hose to fitting.
Prevent personal injury and/or damage to equipment. Read all WARNINGS, CAUTIONS, and Precautions for Hydraulic Testing at the beginning of this section.
13.If the machine has a Pro Control System installed, reconnect the Pro Control console computer.
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4. Disconnect hydraulic hose from the CF port fitting in the PWM Valve (Fig. 22).
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IMPORTANT: Make sure that the oil flow indicator arrow on the flow meter is showing that the oil will flow from the PWM Valve CF port, through the tester, and into the hydraulic hose. 5. Install tester with pressure gauges and flow meter in series with the CF port fitting and the disconnected hydraulic hose. Make sure the tester flow control valve is fully open.
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6. Make sure that spray tank has sufficient fluid for agitation. Make sure that spray pump is turned off. 7. If the machine has a Pro Control System installed, disconnect the Pro Control console computer.
Figure 22 1. PWM Valve 2. CF port fitting
3. PWM Valve solenoid
8. Start engine and move throttle to high idle speed (3050 – 3150 RPM). The flow meter should indicate little, if any, hydraulic flow (less than 1 GPM) from the PWM Valve CF port. A. If higher flow exists, stop engine, disconnect the PWM Valve solenoid connection from the machine harness and retest. If higher flow still exists, the PWM Valve should be replaced. If flow decreases to less than 1 GPM after solenoid is disconnected, inspect spray system electrical components and wiring before continuing PWM Valve flow test. 9. Make sure that spray booms are off. Turn spray pump and tank agitation on.
Hydraulic System
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Multi Pro 5700–D