Lull 944E-42 Service Manual - Manual (Page 788)

Stabil-TRAK™ System
10.30 Model 644E-42/944E-42 Rev. 6/04
10.8 STABIL-TRAK™ HYDRAULIC CIRCUIT OPERATION AND TROUBLESHOOTING
The function of the Stabil-TRAK™ system varies under
different operating conditions. The basic modes include
the FREE PIVOT MODE, SLOW PIVOT MODE and
LOCKED MODE. The hydraulic operation and troubleshooting information for
each of these modes will be described on the following
pages.
10.8.1 Troubleshooting Symptom Chart
Symptom Conditions Reference
With the boom below 40°, when
swaying the frame to the right, the left
front tire comes off the ground. Ignition ON, engine running
Boom angle is below 40°
Travel select lever is in (F) FORWARD or
(R) REVERSE
Park brake OFF
Service brake DISENGAGED
Refer to Section 10.8.3, “Hydraulic Circuit
Operation - Free Pivot Mode, Rod Oil Out,”
and Section 10.8.4, “Hydraulic
Troubleshooting - Free Pivot Mode, Rod
Oil Out.”
With the boom below 40°, when
swaying the frame to the left, the right
front tire comes off the ground. Ignition ON, engine running
Boom angle is below 40°
Travel select lever is in (F) FORWARD or
(R) REVERSE
Park brake OFF
Service brake DISENGAGED
Refer to Section 10.8.5, “Hydraulic Circuit
Operation - Free Pivot Mode, Base Oil Out,”
and Section 10.8.6, “Hydraulic
Troubleshooting - Free Pivot Mode,
Base Oil Out.”
While traveling, ride feels spongy
(riding on 3 wheels). Ignition ON, engine running
Boom angle is above 40°
Travel select lever is in (F) FORWARD or
(R) REVERSE
Park brake OFF
Service brake DISENGAGED
Refer to Section 10.8.7, “Hydraulic
Circuit Operation - Slow Pivot Mode, Rod
Oil Out,” and Section 10.8.8, “Hydraulic
Troubleshooting - Slow Pivot Mode, Rod
Oil Out,” or Section 10.8.9, “Hydraulic
Circuit Operation - Slow Pivot Mode,
Base Oil Out,” and Section 10.8.10,
“Hydraulic Troubleshooting - Slow Pivot
Mode, Base Oil Out.”
Stabil-TRAK™ lock light in the front
dash is not ON. Ignition ON, engine running
Boom angle is above 40°
Travel select lever is in (N) NEUTRAL, or
Park brake ON, or Service brake ENGAGED
Refer to Section 10.8.11, “Hydraulic
Circuit Operation - Locked Mode,” and
Section 10.8.13, “Hydraulic
Troubleshooting - Locked Mode, Will Not
Frame Sway Right,” or Section 10.8.15,
“Hydraulic Troubleshooting - Locked
Mode, Will Not Frame Sway Left.”
With the boom above 40°, when
swaying the frame to the right, the left
front tire comes off the ground. Ignition ON, engine running
Boom angle is above 40°
Travel select lever is in (N) NEUTRAL, or
Park brake ON, or Service brake
ENGAGED
Refer to Section 10.8.12, “Hydraulic
Circuit Operation - Locked Mode, Frame
Sway Right,” and Section 10.8.13,
“Hydraulic Troubleshooting - Locked
Mode, Will Not Frame Sway Right.”
With the boom above 40°, when
swaying the frame to the left, the right
front tire comes off the ground. Ignition ON, engine running
Boom angle is above 40°
Travel select lever is in (N) NEUTRAL, or Park
brake ON, or Service brake ENGAGED
Refer to Section 10.8.14, “Hydraulic
Circuit Operation - Locked Mode, Frame
Sway Left,” and Section 10.8.15,
“Hydraulic Troubleshooting - Locked
Mode, Will Not Frame Sway Left.”