SECTION 2 - GENERAL
3121619
2-5
2.4
CYLINDER DRIFT
Theory
When a hydraulic cylinder is supporting a load, cylinder drift
may occur as a result of any of the circumstances below:
• Normal leakage of load holding valves or malfunction of
load holding valves. See Cylinder Leakage Test and Table 2-
2, Cylinder Drift below for evaluation.
• Damaged or worn piston seals.
• Normal thermal expansion or contraction of the hydraulic
oil within cylinders (See Cylinder Thermal Drift below).
The first two circumstances may result in cylinder movement
due to oil leaking out of the cylinder externally or by leaking
back to tank or due to oil leaking internally from one cylinder
chamber to the other.
Thermal expansion or contraction of oil in hydraulic cylinders
is a normal occurrence and does not result in oil leaking out of
the cylinder or leaking internally from one cylinder chamber
to the other. Thermal expansion or contraction is the tendency
for materials to change size in response to a change in temper-
ature.
Cylinder Leakage Test
Cylinder oil must be at stabilized ambient temperature
before beginning this test.
Measure drift at cylinder rod with a calibrated dial indicator.
In an area free of obstructions, cylinder must have load
applied and appropriately positioned to detect drift.
Cylinder leakage is acceptable if it passes this test.
Cylinder Thermal Drift
The oil in all hydraulic cylinders will expand or contract due to
thermal effects over time and may result in changes to the
boom and/or platform position while the machine is station-
ary. These effects occur as the cylinder oil changes tempera-
ture, usually from a higher oil temperature as it cools and
approaches the ambient air temperature. Results of these
effects are related to several factors including cylinder length
and change in temperature over the time the cylinder remains
stationary.
Table 2-2. Cylinder Drift
Cylinder Bore Diameter
Max. Acceptable Drift
in 10 Minutes
inches
mm
inches
mm
3
76.2
0.026
0.66
3.5
89
0.019
0.48
4
101.6
0.015
0.38
5
127
0.009
0.22
6
152.4
0.006
0.15
7
177.8
0.005
0.13
8
203.2
0.004
0.10
9
228.6
0.003
0.08
NOTE:
This information is based on 6 drops per minute cylinder
leakage.
Summary of Contents for 1850SJ
Page 1: ...Service and Maintenance Manual Model 1850SJ 3121619 June 29 2018 Rev J AS NZS...
Page 2: ......
Page 21: ...3121619 xvii LIST OF FIGURES FIGURE NO TITLE PAGE NO Thispageleftblankintentionally...
Page 24: ...xx 3121619 LIST OF TABLES TABLE NO TITLE PAGE NO Thispageleftblankintentionally...
Page 50: ...SECTION 2 GENERAL 2 12 3121619 NOTES...
Page 55: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 5 This page left blank intentionally...
Page 56: ...SECTION 3 CHASSIS TURNTABLE 3 6 3121619 Figure 3 4 Axle Hose Routing Sheet 1 of 2...
Page 57: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 7 Figure 3 5 Axle Hose Routing Sheet 2 of 2...
Page 58: ...SECTION 3 CHASSIS TURNTABLE 3 8 3121619 Figure 3 6 Steering Axle Hydraulic Circuit...
Page 61: ...SECTION 3 CHASSIS TURNTABLE 3121619 3 11 Figure 3 9 Turntable Hydraulic System...
Page 92: ...SECTION 3 CHASSIS TURNTABLE 3 42 3121619 Figure 3 39 Swing Bearing Wear Tolerance...
Page 94: ...SECTION 3 CHASSIS TURNTABLE 3 44 3121619 Figure 3 41 Swing Bearing Removal Sheet 2 of 4...
Page 110: ...SECTION 3 CHASSIS TURNTABLE 3 60 3121619 Figure 3 54 Engine Electrical Circuit...
Page 169: ...SECTION 4 BOOM PLATFORM 3121619 4 7 Figure 4 1 Boom Hydraulic System...
Page 173: ...SECTION 4 BOOM PLATFORM 3121619 4 11 Figure 4 2 Boom Assembly Sheet 1 of 9...
Page 174: ...SECTION 4 BOOM PLATFORM 4 12 3121619 Figure 4 3 Boom Assembly Sheet 2 of 9...
Page 175: ...SECTION 4 BOOM PLATFORM 3121619 4 13 Figure 4 4 Boom Assembly Sheet 3 of 9...
Page 176: ...SECTION 4 BOOM PLATFORM 4 14 3121619 Figure 4 5 Boom Assembly Sheet 4 of 9...
Page 177: ...SECTION 4 BOOM PLATFORM 3121619 4 15 Figure 4 6 Boom Assembly Sheet 5 of 9...
Page 178: ...SECTION 4 BOOM PLATFORM 4 16 3121619 Figure 4 7 Boom Assembly Sheet 6 of 9...
Page 179: ...SECTION 4 BOOM PLATFORM 3121619 4 17 Figure 4 8 Boom Assembly Sheet 7 of 9...
Page 180: ...SECTION 4 BOOM PLATFORM 4 18 3121619 Figure 4 9 Boom Assembly Sheet 8 of 9...
Page 181: ...SECTION 4 BOOM PLATFORM 3121619 4 19 Figure 4 10 Boom Assembly Sheet 9 of 9...
Page 187: ...SECTION 4 BOOM PLATFORM 3121619 4 25 Figure 4 16 Boom Assembly Torque Values Sheet 1 of 4...
Page 188: ...SECTION 4 BOOM PLATFORM 4 26 3121619 Figure 4 17 Boom Assembly Torque Values Sheet 2 of 4...
Page 189: ...SECTION 4 BOOM PLATFORM 3121619 4 27 Figure 4 18 Boom Assembly Torque Values Sheet 3 of 4...
Page 190: ...SECTION 4 BOOM PLATFORM 4 28 3121619 Figure 4 19 Boom Assembly Torque Values Sheet 4 of 4...
Page 201: ...SECTION 4 BOOM PLATFORM 3121619 4 39 Figure 4 20 Hose Adjustment...
Page 202: ...SECTION 4 BOOM PLATFORM 4 40 3121619 Figure 4 21 Section 3 Boom Cables...
Page 203: ...SECTION 4 BOOM PLATFORM 3121619 4 41 Figure 4 22 Section 4 Boom Cables...
Page 204: ...SECTION 4 BOOM PLATFORM 4 42 3121619 Figure 4 23 Section 5 Boom Cables...
Page 205: ...SECTION 4 BOOM PLATFORM 3121619 4 43 Figure 4 24 Jib Hydraulics Sheet 1 of 7...
Page 234: ...SECTION 4 BOOM PLATFORM 4 72 3121619 Figure 4 44 Powertrack Shimming Instructions...
Page 239: ...SECTION 4 BOOM PLATFORM 3121619 4 77 Figure 4 49 Powertrack Hose Installation Sheet 1 of 4...
Page 240: ...SECTION 4 BOOM PLATFORM 4 78 3121619 Figure 4 50 Powertrack Hose Installation Sheet 2 of 4...
Page 241: ...SECTION 4 BOOM PLATFORM 3121619 4 79 Figure 4 51 Powertrack Hose Installation Sheet 3 of 4...
Page 242: ...SECTION 4 BOOM PLATFORM 4 80 3121619 Figure 4 52 Powertrack Hose Installation Sheet 4 of 4...
Page 252: ...SECTION 4 BOOM PLATFORM 4 90 3121619 NOTES...
Page 432: ...SECTION 5 BASIC HYDRAULIC INFORMATION HYDRAULIC SCHEMATICS 5 180 3121619 NOTES...
Page 527: ...SECTION 6 JLG CONTROL SYSTEM 3121619 6 95 Figure 6 36 LSS Installation Sheet 1 of 4...
Page 528: ...SECTION 6 JLG CONTROL SYSTEM 6 96 3121619 Figure 6 37 LSS Installation Sheet 2 of 4...
Page 529: ...SECTION 6 JLG CONTROL SYSTEM 3121619 6 97 Figure 6 38 LSS Installation Sheet 3 of 4...
Page 530: ...SECTION 6 JLG CONTROL SYSTEM 6 98 3121619 Figure 6 39 LSS Installation Sheet 4 of 4...
Page 710: ...SECTION 7 BASIC ELECTRICAL INFORMATION ELECTRICAL SCHEMATICS 7 118 3121619 NOTES...
Page 711: ......