Nilfisk-Advance 56507009, Troubleshooting Manual

Page: 57 / 82

FORM NO. 56043129 - SR 1900 - 57
Test port
ENGINE
3,000 PSI (207 bar)
cm) 6,000 PSI (414 bar)
Parker Diagnostics PD222
HYDRAULIC SYSTEM
HYDRAULIC SYSTEM TROUBLESHOOTING
Accurate measurements are the key to troubleshooting a hydraulic system. Once measurements are obtained, they can be compared with specifications to analyze
a problem.
To troubleshoot the hydraulic system it is possible to use digital tachometers, flow gauges or pressure gauges. The pressure gauge should have a range of 0 –
3000 PSI (see Figure 2) and have a Parker Diagnostics connector number PD222. The most convenient way to check for oil flow is to check the RPM of the motor
that is performing poorly. Use the chart on the next page to determine the motor RPM, if the motor speed is correct the pump is producing the correct amount of
oil flow. However, this does not mean that, if a motor is running too slow the problem is in the pump.
The following information should be used to check for proper motor RPM, system pressure and relief valve settings. The readings are nominal figures and there
will be variations due to manufacturer tolerances and system oil temperature. If any reading varies greater than 20% there will be a noticeable loss of performance
and should be corrected.
TEST PORT NOMINAL PRESSURE READINGS (see Figure 1)
• Insert pressure gauge (see Figure 1) into the test port.
• Run engine in high throttle position. Allow oil to warm up.
• The bypass pressure is the pressure reading with no motor or cylinder operating.
• The operational pressure is the pressure range the motor or cylinders will operate in.
Note: 100 PSI = 6.9 bar
• A much lower than normal bypass pressure could indicate a gear pump problem.
• If the bypass pressure remains the same after turning the function on, there could be a problem in the control valve or circuit.
• If the operational pressure is within range but the motor speed is too slow the problem could be in the motor.
• If the broom motor Operational PSI reading is above the Bypass PSI but is below the Operational PSI check the broom adjustment and wear.
• Check individual system troubleshooting sections of this manual for additional information.
FIGURE 1
FIGURE 2