CONTENTS______________________ 5 Decals Decal Location - JT921/JT921S ............................. 8 Engine Components Air Filter System - Caterpillar Diesel ...................... 22 Engine - Caterpillar Diesel ..................................... 14 Engine Installation - Caterpillar Diesel ................... 16 Engine Service - Caterpillar Diesel ........................ 18 Fuel Filter System - Caterpillar Diesel ................... 24 Radiator - Caterpillar Diesel .................................. 20 Throttle - Caterpillar Diesel .................................... 26 Frame Components Carriage ............................................................
36 Covers - Caterpillar Diesel ..................................... 46 Cylinder Grease ............................................... 54 Drill Frame Components .................................. 30 Fuel Reservoir .................................................. 44 Gear Box - Rotation Drive ..................................... 40 Idler .................................................................. 50 Stabilizer - Rear ................................................. 48 Tension Spring ................................................. 52 Track Group - Rubber ......................................... 42 Wrench - Front ...................................................
34 Operator’s Station Console Gauges ............................................... 62 Operators Station Gauges................................ 60 Seat Mount ....................................................... 58 Hydraulics Anchor Drive Hydraulics ................................. 126 Anchor Hydraulics .......................................... 122 Auxiliary Backup Wrench Hydraulic ............... 116 Breakout Hydraulics ....................................... 114 Carriage Rotation Hydraulics ......................... 102 Carriage Thrust Hydraulics ............................. 108 Control Valve & Levers ...................................
100 Control Valve/Levers - 3-Spool ........................... 96 Drive Control Supply Hydraulics ....................... 78 Drive Control Valve & Levers ........................... 82 Frame Tilt Hydraulics ....................................... 84 Ground Drive Hydraulics .................................. 80 Hydraulic Control Valve - 2-Spool ....................... 94 Hydraulic Control Valve - 2-Spool ....................... 98 Hydraulic Cylinder (2.0”X1.0”) ............................ 130 Hydraulic Cylinder (3.0”X1.5”) ............................ 132 Hydraulic Diagram ............................................ 70 Hydraulic Diagram - Auto-bore ............................
68 Hydraulic Motor - Tapered Keyed Shaft 1-1/4” ......... 128 Hydraulic Reservoir .......................................... 72 Hydraulic Schematic - w/Auto-bore shutoff ............ 66 Main Supply Hydraulics .................................... 92 Mud Motor Hydraulics .................................... 118 Oil Cooler Hydraulics ........................................ 74 Oil Cooler Hydraulics - Caterpillar Diesel .............. 76 Rotation Hydraulics - Auto-bore ........................ 106 Rotation Hydraulics ........................................ 104 Stabilizer .......................................................... 88 Stabilizer Hydraulics .........................................
86 Thrust Hydraulics - Auto-bore ........................... 112 Thrust Hydraulics ........................................... 110 Track Extended Hydraulics .............................. 90 Electrical Electrical Diagram .......................................... 150 Electrical Diagram - Console ............................ 158 Electrical Diagram - Engine Frame .................... 152 Electrical Diagram - Gauge Buss ....................... 162 Electrical Diagram - Gauge, Auto-bore ................ 148 Electrical Schematic - Auto-bore ....................... 136 Electrical Schematic - JT920 T2 ....................... 142 Electrical Strike System .................................
156 Lubricator Systems Thread Lubricator - Begins .............................. 168 Anchor Systems Anchor Counterbalance Weight ..................... 174 Anchor System ............................................... 172 Anchoring Parts ............................................. 176 Hydraulic Stake Driver ................................... 178 Fluid Systems Fluid Pump Plumbing ..................................... 194 Mud Pump ...................................................... 184 Mud Pump - 9 GPM .......................................... 186 Mud Pump Plumbing w/o Tank ...................... 190 Mud Pump Plumbing ......................................
188 Mud Tank Plumbing ....................................... 192 Tank Support ................................................. 182 Pipe Loader Systems Drill Pipe Accessories .................................... 198 Accessories Drilling Fluid Transfer ..................................... 212 Garden Hose Adapter .................................... 210 Grounding Cables .......................................... 204 Mud Mixing Accessories ................................ 202 Wash Wand ................................................... 208 Water Transfer System .................................. 206 Miscellaneous Bolt/Nut Torque Chart ....................................
216 Filters ............................................................. 220 Optional Kits ................................................... 221 Parts Manual Change Request ...................... 223 Related Publications ...................................... 220 Replacement O-Ring Chart ............................ 219 Warranty Registration .................................... 226 ID0135192