Vibration System and Steering RD 12 / RD 12Awc_tx000668gb.fm 586.2 Troubleshooting a System that Vibrates PoorlyPrerequisites 3000-psi pressure gauge Compactible surface such as a bed of gravel or old tiresBackground The exciter pump is designed to put out a constant flow of oil at a set engine speed.This ensures that the vibration frequency remains steady. When troubleshootingthe exciter circuit, the vibration speed, operating pressure, and relief pressuresmust be known to help determine the cause of any problems.Procedure To measure vibration speed:1. Start the machine and run it for several minutes to bring the hydraulic fluid up tonormal operating temperature.2. Drive the machine onto a compactible surface such as a bed of gravel or oldtires.3. Run the machine at full throttle. Check the engine RPM using a tachometer orvibrotach. The engine must be running at the correct RPM to accurately mea-sure vibration.4. Start vibration. Hold the vibrotach (P/N 53397) against the outer rim of the drumand measure the vibration speed.5. Shut down the machine.To check vibration system operating pressure:1. Open the engine compartment.2. Locate the exciter solenoid valve (a).3. Connect a 3000-psi gauge to the test port (b).4. Start the engine and run the machine at full throttle.This procedure continues on the next page.Engine RPM Vibration FrequencyVPM3100 4200
