Manitowoc 999 Service And Maintenance Manual

Reference Only
TROUBLESHOOTING 999 SERVICE/MAINTENANCE MANUAL
10-10
Published 05-16-17, Control # 233-03
Problem 8
No front or rear load drum operation.
POSSIBLE CAUSES
Load drum disc brake not releasing; Load drum pawl not released or hung up; No voltage through control handle to PC controller;
No voltage out of PC controller to pump EDC; Wiring or switch is damaged.
CHECKS
Diagnostic display DRUM 1or 2 screen (bank 4) displays 1 when handle is moved in problem direction?
Yes No
Engine loads when moving problem handle in either direction?
Is drum brake switch in correct position?
Yes No
Yes
No
Use test plug adapter. (See Test 11.) Is 12 volts
present at disc brake solenoid (80E or 81E)
when problem handle is moved?
Yes
No
Consult dealer/factory.
Move switch to correct position.
Repair or replace wiring or switch.
Consult dealer/factory.
When moving problem handle in both directions, does DRUM 1, 2, or 3
diagnostic screen (bank 1) obtain 100% handle control in each direction?
Yes No
Does drum turn while moving
handle and actuating manual
override on brake valve?
Replace valve.
Yes No
When moving problem handle in both directions,
does DRUM 1, 2, or 3 diagnostic screen (bank 2)
obtain 100% pump control in each direction?
Yes No
Voltage at handle (80P or 81P) is
more than 0 with handle moved?
(See Test 7.)
Yes
No
Is there an operating or system fault when handle is moved?
Correct problem.
Yes No
Consult dealer/factory.
Is pressure at brake more than
300 psi?
Repair or replace brake.
Yes No
Is system Charge pressure
more than 300 psi?
Readjust charge pressure
relief or replace pump.
Yes
No
Replace brake valve.
Manually stroke pump (See Test 16.) Does
pump pressurize?
Use test plug adapter. (See Test 13.)
Is voltage present at pump EDC?
Yes No
Yes
No
Replace pump EDC.
Repair or replace wiring
or consult dealer/factory.
Is 10 volts at handle (87FA)?
Yes
No
Repair or replace handle.
Replace fuse F12 (87FA) and/or
wiring. (See Test 6.)
Isolate pump. Does manually stroked pump
pressurize?
Yes No
Repair or replace
motor.
Repair or replace
pump.
When moving problem handle fully in both directions,
A1 diagnostic screen (banks 1and 2) reads 38 to 120
in lower or 136 to 215 in raise?
Yes
No
Repair or replace control handle/wiring

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English