Manitowoc 999 Service And Maintenance Manual

Reference Only
Manitowoc Published 05-16-17, Control # 233-03 10-9
999 SERVICE/MAINTENANCE MANUAL TROUBLESHOOTING
10
Problem 7
Crawlers will not travel in either direction (one or both tracks).
POSSIBLE CAUSES
Brake valve, control handle, or EDC faulty; No voltage from handle to PC controller; No voltage out
of PC controller to pump EDC; Low brake pressure; Wiring or switch is faulty; Pump, motor or gearbox is damaged.
CHECKS
Diagnostic display TRACK screen (bank 7) displays 1 when problem handle is moved in problem direction?
Yes No
Engine loads when moving problem handle in either direction?
Is travel brake switch in OFF position?
NoYes
NoYes
Use test plug adapter. (See Test 12.) Is 12
volts present at hydraulic brake solenoid
(84E), when problem handle is moved?
No
Yes
Is 12 volts present at brake switch?
Move switch to
OFF position.
Yes No
Repair or replace wiring or switch.
Consult dealer/factory.
When moving problem handle in both directions,
does TRACK diagnostic screen (banks 1 or 3)
obtain 100% handle control in each direction?
NoYes
Replace switch,
fuse or wiring.
Does track turn while moving
handle and actuating manual
override on brake valve?
No
Yes
When moving problem handle in both directions,
does TRACK diagnostic screen (banks 3 and 4)
obtain 100% pump control in each direction?
NoYes
Voltage at handle (83P or 84P) is
greater than 0 with handle moved?
(See Test 7.)
No
Yes
Replace solenoid.
Is pressure at brake more than
300 psi?
No
Yes
Manually stroke pump (See Test 16.) Does pump
pressurize?
Consult dealer/factory.
NoYes
Repair brake or gear box.
Is system charge pressure more
than 300 psi?
Replace brake valve.
Re-adjust charge pressure
relief or replace pump.
NoYes
Use test plug adapter. (See
Test 13.) Is voltage present
at pump EDC?
NoYes
Replace pump EDC.
Repair or replace wiring
or consult dealer/factory.
Isolate pump. Does manually stroked pump
pressurize?
Repair or replace motor.
Repair or replace pump.
NoYes
Is 10 volts at handle (87FA)?
No
Yes
Repair or replace handle.
Repair or replace fuse (F12) and/or
wiring. (See Test 6.)
When moving problem handle fully in both directions,
A1 diagnostic screen (banks 4 or 5) reads 38 to 120
in reverse or 136 to 215 in forward?
Yes
No
Repair or replace control handle/wiring.
Consult dealer/factory.

Manitowoc 999 Specifications

General

Brand	Manitowoc
Model	999
Category	Construction Equipment
Language	English