Manitowoc Grove RT540E Service Maintenance Manual

Published 4-20-2015, Control # 502-01 2-7
RT540E SERVICE MANUAL HYDRAULIC SYSTEM
2
GROVE
limits. If this condition exists, the spool and body must be
replaced as an assembly.
Valve Leakage
Dripping hydraulic oil indicates some type of external
leakage. The machine should be removed from service for
immediate repairs. External leaks sometimes develop at
fittings and seals. Seals may be damaged by temperatures
that are too high, or by dirt or paint accumulation on the
spool. Damaged or torn seals must be replaced.
A component functioning at reduced efficiency may indicate
that the control valve for that component is leaking internally.
If preliminary check-out reveals that adequate volume is
being supplied to the affected valve bank, relief valves are
properly adjusted, and the component is not at fault, check
the valve for scored or worn parts. Scoring is a sign of the
number one problem in hydraulics - contamination (external
contamination by dust or internal contamination by debris
from deteriorating components or oxidized hydraulic oil).
Scored or severely worn valve components must be
replaced.
Check valves in the control valves are designed to permit a
flow of hydraulic oil in one direction only. If a piece of dirt or
rust has worked its way into the check valve and lodges
between the poppet and seat, it will keep the valve open and
allow a return flow of hydraulic oil. The remedy is to clean the
valve, but it is also a good idea to follow through and ensure
the hydraulic system filter is still serviceable.
Binding Spools
Some of the most common causes for stiff spool movement
or jammed spool action are system overheating, excessive
pressure, contaminated or deteriorated hydraulic oil, or
warped mountings. When scorched, deteriorated hydraulic
oil or contamination is the cause, flushing the system and
replenishing with clean hydraulic oil may solve the problem.
If the spool bores are badly scored or galled, the valve must
be removed for servicing.
Warping occurs when mounting plates are not level or they
become distorted from machine damage. As mentioned
previously, the valve can be shimmed level.
Also, check the valve for rust. Rust or dirt collecting on the
valves can prevent free movement of the spool, and keep it
from the true center position. Excessive system pressure
can create both internal and external leaks in valves that are
otherwise sound. Only qualified technicians using the correct
equipment should make pressure adjustments when
pressure adjustments are needed.
Reference Only

Manitowoc Grove RT540E Specifications

General

Brand	Manitowoc
Model	Grove RT540E
Category	Construction Equipment
Language	English