Theory Of Operation; Maintenance - Manitowoc Grove TMS700E Service And Maintenance Manual

BOOM
section at a given length, oil is trapped in the cylinder by the
holding valve. Refer to Hydraulic Remote Control Valve,
page 2-34 for a complete description of the holding valve.

Theory of Operation

Flow from the pump travels to the telescope directional
control valve. Movement of the control lever for telescope

Maintenance

Troubleshooting
SYMPTOM
1. Erratic operation of
extending
telescoping
cylinder.
4-16
PROBABLE CAUSE
a. Low hydraulic oil level.
b. Damaged relief valves.
c. Air in telescope cylinder.
d. Low engine rpm.
e. Lack of lubrication on boom sections.
f. Extremely tight boom
sheaves.
g. Improper boom alignment caused from
side loading.
h. Worn boom wear pads.
i. Distorted boom section.
j. Damaged telescope cylinder.
k. Clogged, broken, or loose hydraulic
lines or fittings.
l. Damaged control valve.
Published 01-29-2015, Control # 512-01
TMS700E SERVICE MANUAL
functions from neutral sends a pilot pressure signal to the
directional control valve to shift the spool in the directional
control valve. This aligns the appropriate passages in the
control valve to route oil to the telescope cylinders.
Also refer to Theory of Operation, page 4-1 in this Section.
a. Check for leaks. Repair any found.
Replenish hydraulic oil to proper level.
b. Repair or replace relief valves.
c. Bleed by lowering telescope cylinder
below horizontal.
d. Increase engine rpm to proper setting.
e. Properly lubricate all boom sections.
extension f. Inspect and properly lubricate boom
extension sheaves.
g. Reduce and properly hoist load.
h. Replace wear pads and properly
lubricate.
i. Replace distorted section.
j. Repair or replace cylinder.
k. Clean, tighten, or replace lines or
fittings.
l. Repair or replace control valve.
SOLUTION