Manitowoc 999, Service And Maintenance Manual

Page: 259 / 298

Reference
Only
Manitowoc
Published 05-16-17, Control # 233-03
10-23
999 SERVICE/MAINTENANCE MANUAL TROUBLESHOOTING
10
350 psi not obtained
CHECKS
Is hydraulic oil level in reservoir OK and
shut-off valve fully open?
Problem 20
Hydraulic system is operating hot.
POSSIBLE CAUSES
Low hydraulic oil level in reservoir; Heat exchanger problem; Dirty filter;
System multifunction valves are not set correctly; Pump or motor problem.
Yes
No
Fill tank to full level or open shut-off valve.
Is heat exchanger radiator clean?
Yes
No
Clean, repair or replace heat exchanger radiator.
Yes No
System charge pressure is 350 psi at pressure sensor station?
Yes No
System multifunction valves are
operating at the recommended
system pressures?
Are suction filters clean?
Replace filters.
Yes
No
Adjust or replace problem
valve. (See Test 19.)
Adjust charge pressure relief valve for 350 psi. (See Test 18.)
350 psi obtained
System should be at correct temperature.
Check for internal leakage at pump and motor. (See Test 21.)
Normal High Leakage
Is system operating pressure excessive?
Yes No
Repair or replace pump or motor, as required.
Repair or replace pump or motor, as required. Locate and reduce load on
motor transmission.