D3 Crawler S/n 6N1 & 79U1 & up Volume 1 of 2

Caterpillar Service Manual D3 Crawler S/n 6N1 & 79U1 & up Volume 1 of 2 Service Manual THIS IS A MANUAL PRODUCED BY JENSALES INC. WITHOUT THE AUTHORIZATION OF CATERPILLAR OR IT S SUCCESSORS. CATERPILLAR AND IT S SUCCESSORS ARE NOT RESPONSIBLE FOR THE QUALITY OR ACCURACY OF THIS MANUAL. TRADE MARKS AND TRADE NAMES CONTAINED AND USED HEREIN ARE THOSE OF OTHERS, AND ARE USED HERE IN A DESCRIPTIVE SENSE TO REFER TO THE PRODUCTS OF OTHERS. CT-S-D3 6N1,79

(SIN 6N1, 79U1 & UP)

C~TERPILLAR REG01454-01 July 1973 W l@iti1u@ @~ [f ~O@[fi) U ~O[fi) Alternator System (Nippondenso Co. LTD) ~ ~c9]d(ill~o[fi)

NIPPONDENSO ALTERNATOR SYSTEMS CONTENTS TABLE OF CONTENTS 4N4540 & 6N5460 ALTERNATORS Specifications... 5 Construction... 5 Troubleshooting...,... 6 Battery... 6 Charging System......................................................... 7 Component Checks......................................................... 9 Check of Alternator Output... 9 Check of Rectifier (Diodes) (4N4540 Alternator)............................ 9 Check of Rectifier and Stator (6N5460 Alternator)... 10 Check of Rectifier (Diodes) (6N5460 Alternator)... 10 Check of Stator Coil...................................................... 10 Check of Rotor Coil... 11 Check of Brush Wear... 12 Check of Slip Ring... 12 Disassembly... 13 Assembly... 15 4N5110 REGULATOR (EXTERNAL) Operation... 18 Features... 18 Handling Precautions..................................................... 19 Principals of Voltage Regulation... 19 Performance Inspection................................................... 20 7N4784, 7N6118 & 8N2268 ALTERNATORS (7N5961 INTEGRAL REGULATOR) Specifications... 22 Features... 23 Construction... 24 Operation.................................................................. 26 Engine Not Running...................................................... 26 Initial Field Excitation Just After Engine Start-Up........................... 26 Alternator-Generated Voltage Still Lower Than Regulator-Setting Voltage............................................... 27 Alternator-Generated Voltage Higher Than Regulator-Setting Voltage............................................... 27 Output Voltage Versus Alternator Speed................................... 28 Handling Precautions..................................................... 28 Troubleshooting............................................................ 29 Performance Inspection..................................................... 30 Component Checks......................................................... 30 Check of Rectifier... 30 Check of Stator Coil...................................................... 31 Check of Rotor Coil... 31 Check of Brush Wear..................................................... 31 Check of Slip Ring........................................................ 32 Check of I.C. Regulator................................................... 32 Disassembly................................................................ 33 Assembly... 36 3

ASSEMBLY 4N4540 & 6N5460 ALTERNATORS 4. Install bearing, retainer plate, felt and bearing. Fill bearing with Denso No. 50 grease. Install three screws in retainer cover (FIG. 25). 5. Install rotor shaft into drive end frame. Install pulley and fan (FIG. 26). FIG. 25 INSTALLING COVER PLATE FIG. 26 ASSEMBLE THE DRIVE ASSEMBLY 6. Install rotor core in a vise. Tighten pulley lock nut (FIG. 27). Alternator 4N4540 6N5460 Pulley Nut Torque 304.5 to 435.0 lb. in. (34.0 to 49.0 Nom) 435.0 to 652.5 lb. in. (49.0 to 74.0 Nom) CAUTION Do not tighten the vise too much because damage to core could result. FIG. 27 TIGHTEN THE PULLEY LOCK NUT 16

Index Specifications Specifications... 4 Systems Operation Components... 10 Introduction... 9 Starting Motor Operation... 12 Component Operation... 12 General Operation... 12 Starting Operation... 14 Testing And Adjusting Off Machine No Load Test... 20 On Machine Starting Motor Diagnosis... 18 Diagnosis Procedure... 19 General Information... 18 System Voltage... 19 Starting Motor Component Tests... 23 Armature Tests... 24 Brush and Brush Holder Checks... 26 Field Winding Tests... 23 Pinion Drive Checks... 26 Shunt Coil Tests... 23 Starting Motor Solenoid Tests... 21 Hold-In Winding Test... 22 Pull-In Winding Test... 22 Troubleshooting... 16 Problem List... 16 Problems... 16 Disassembly And Assembly Assemble Starting Motor 1453-016... 32 Disassemble Starting Motor 1453-015... 30 Nippondenso Starting Motors 3 Index

ENGINE DISASSEMBLY AND ASSEMBLY INDEX Accessory Drive... 57-59 Accessory Drive, Disassemble & Assemble......... 60-63 Air Cleaner Housing........................... 83 Alternator... 11 Camshaft... 70-72 Camshaft Bearing... 73 Connecting Rod Bearing... '.................. 37 Crankshaft Front Pulley..................... 64 Crankshaft Front Seal........................... 65 Crankshaft and Gear... 80,81 Crankshaft Main Bearings............... 38,39 Crankshaft Rear Seal and Wear Sleeve...... 79 Cylinder Head (Direct Injection)... 30,31 Cylinder Head (Precombustion Chamber)............... 32,33 Cylinder Head, Disassemble & Assemble......... 34,35 Engine (910)............... 86,87 Engine (D3, 931)... 88-91 Engine Oil Cooler........................... 7 Exhaust Manifold... :... 64 Flywheel... 77 Flywheel Housing... 78 Flywheel Ring Gear... 78 Fuel Injection Lines.............................. 18 Fuel Injection Nozzles.................. 25,26 Fuel Injection Nozzles, Disassemble & Assemble.................. 26-29 Fuel Priming Pump........................ 8 Fuel Injection Pump Housing, Disassemble & Assemble......... 52-56 Fuel Injection Pump Housing and Governor............... 44,45 Fuel Injection Pump Housing and Governor, Separation and Connection... 46,47 Fuel Injection Valves.................. 20 Fuel Transfer Pump.............................. 8 Fuel Transfer Pump, Disassemble & Assemble... 9,10 Glow Plugs.............................. 19 Governor, Disassemble & ASl1emble... 48-51 Hood... 82 Muffler... 83 Oil Pan... 31 Oil Pump and Relief Valve... 68-70 Pistons........................... 39,40 Pistons (Direct Injection), Disassemble & Assemble... 41,42 Pistons (Precombustion Chamber), Disassemble & Assemble...... 42,43 Precombustion Chambers... 21 Radiator & Guard Assembly............... 84,85 Rocker Shaft, Disassemble & Assemble......... 23,24 Rocker Shaft and Push Rods (Direct Injection)............ 22,23 Rocker Shaft and Push Rods (Precombustion Chamber)... 21,22 Starting Motor... 7 Timing Gear Cover..................... 66,67 Timing Gears and Plate... 74-76 Valve Cover (Direct Injection)............... 18 Valve Cover (Precombustion Chamber)..................... 19 Valve Lifters............................................. 36 Water Pump........................ 12 Water Pump, Disassemble & Assemble... 13-17 Water Temperature Regulator... 11 & WARNING DISCONNECT BATTERIES BEFORE PERFORMANCE OF ANY SERVICE WORK. 6

ENGINE DISASSEMBLY AND ASSEMBLY REMOVE CRANKSHAFT AND GEAR 1201 & 1204-11 CRANKSHAFT AND GEAR Tools Needed 887548 Puller Assembly 8H684 Ratchet 80x Wrench 887560 Step Plate 887551 8earing Puller Attachment A start by: a) remove flywheel housing b) remove timing gear cover c) remove pistons 1. Tum the crankshaft until the "C" mark on the crankshaft gear is in alignment with the "C" mark on the camshaft gear as shown. NOTE: The main bearing caps are installed with the part number toward the front of the engine. Each cap has a number on the bottom of the cap, which is the same as the number on the camshaft side of the cy linder block. 2. Remove the three center main bearing caps and thrust bearing. 3. Install one of the flywheel bolts in the end of the crankshaft. Fasten a hoist. 4. Remove the two end caps. CAUTION Be extra careful not to cause damage to the crankshaft journals when the crankshaft is removed. 5. Remove the crankshaft. The weight is 100 lb. (45 kg). 6. Remove the crankshaft main bearings from the cylinder block and from the main bearing caps. 7. Install tooling (A) and remove the gear from the crankshaft. 80

3204 VEHICULAR ENGINE SPECIFICATIONS INTRODUCTION The specifications given in this book are on the basis of information available at the time it was written. The specifications torques, pressures of operation, measurements, adjustments and other items can change at any time. These changes can effect the service given to the product. Get the complete and most current information before you start any job. Caterpillar Dealers have the most current information which is available. For a list of the most current modules and form numbers available for each Service Manual, see the SERVICE MANUAL CONTENTS MICROFICHE REGl139F. When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is equal to or within the specification given, use the part again. When the word "permissible" is in the description, the specification given is the' 'maximum or minimum" tolerance permitted before adjustment, repair and/or new parts are needed. A comparison can be made between the measurements of a worn part, and the specifications of a new part to find the amount of wear. A part that is worn can be safe to use if an estimate of the remainder of its service life is good. If a short service life is expected, replace the part. 77200X2 NOTE: The "C" is an indication of a change from the former issue. NOTE: For Systems Operation and Testing and Adjusting, make reference to the 3204 Vehicular Engine, Form No. REGO 1222. INDEX Accessory Drive Gear................................... 18 Air Induction and Exhaust System Air Cleaner........................................... 20 Camshaft.......................... 19 Cylinder Head 01... 26 PC... 25 Exhaust Manifold... 26 Muffler............................................... 27 Timing Gears......................................... 19 Valve Cover... 24 Valve Rocker Arms and Lifters......................... 20 Valves and Valve Springs.............................. 21 Valve Seats and Inserts 01... 23 PC... 22 Basic Engine Components Connecting Rod... 32 Crankshaft... 34 Bearing Surface (Journal) - Connecting Rods..... 35 Bearing Surface (Journal) - Mains.................. 36 Cylinder Block........................................ 31 Engine Supports...................................... 37 Flywheel... 37 Flywheel Housing............................... 37 Flywheel Housing Bore................................ 38 Flywheel Housing Runout...,... '"............ 39 Flywheel Runout...................................... 40 Pistons and Rings..................................... 33 Cooling System Pressure Cap......................................... 30 Water Pumps......................................... 29 Water Temperature Gauges... 30 Water Temperature Regulators (Thermostat)... 30 Vee Belts............................................. 45 Electrical System Alternators... 42 Alternator I nstaliation... 41 Alternator Regulator... 43 Glow Plug Connection................................ 9 Pressure Switch... 28 Starter Solenoid... 44 Starter Motor......................................... 44 Vee Belts............................................. 45 Engine Design................................. 5 Fuel System, New Scroll Fuel Injection Equipment.............................. 6 Fuel Injection Lines................................... 7 Fuel Injection Nozzles................. 7 Governor.................................... 8 Timing Gears.................................. 8 Fuel System Fuel Injection... "................ 10 Fuel Injection Lines.......................... 12 Fuel Injection Pump Housing... '"............ 9 Fuel Transfer Pump... '"....... 14 Governor................................. 13 Governor Control Linkage...................... 14 Nozzles 01... '"................... 11 PC... 11 Lubrication System Oil Filter.............................................. 28 Oil Pan....................................... 28 Oil Pressure Gauge................................... 28 Oil Pressure Switch................................... 28 Oil Pump... 27 Torque for Flared and O-ring Fittings................. 4

3204 VEHICLE ENGINE INDEX SYSTEMS OPERATION Air Inlet and Exhaust System... 16 Valves and Valve System Components... 17 Basic Block............................................. 25 Camshaft............................................. 25 Connecting Rods... 25 Crankshaft... 25 Pistons and Rings..................................... 25 Cooling System......................................... 23 Electrical System... 26 Charging System Components... 26 Other Components.................................... 27 Starting Circuit Components... 27 Wiring Diagrams... '"......... 27 Engine Design.......................................... 5 Fuel System, New Scroll... 6 Fuel Flow... 6 Fuel Injection Pump................................... 6 Fuel Injection Nozzle.................................. 7 Fuel Transfer Pump................................. 7 Governor... 8 Oil Flow for Fuel Pump and Governor... 10 Fuel System... 12 Fuel Injection Pump.................................. 13 Fuel Injection Valves (Nozzles)... 13 Governor (Hydra-Mechanical)... 14 Lubrication System... 20 Lubrication System (Engines with New Scroll Fuel System)... 18 TESTING AND ADJUSTING Air Inlet and Exhaust System... 113 Com pression... 114 Crankcase (Crankshaft Compartment) Pressure... 114 Cylinder Head... 114 Exhaust Temperature... 113 Measurement of Camshaft Lobes... 116 Measurement of Pressure in Inlet Manifold... 113 Restriction of Air Inlet and Exhaust... 113 Valve Clearance Setting... 115 Basic Block... 123 Connecting Rod and Main Bearings... 123 Con necti ng Rods and Pistons... 123 Cylinder Block... 123 Flywheel and Flywheel Housing... 124 Piston Rings... 123 Cooling System... 119 Testing the Cooling System... 119 Vee Belt Tension Chart... 122 Visual Inspection of the Cooling System... 119 Fuel System, New Scroll... 42 Checking Engine Cylinders Separately................. 42 Checking Engine Timing with 6V3100 Diesel Engine Timing Indicator Group...................... 49 Checking the Plunger and Lifter of an Injection Pump... 46 Checking Timing by Fuel Flow Method................. 50 Checking Timing by Timing Pin Method... 53 Engine Speed Measurement........................... 59 Finding Top Center Compression Position for No.1 Piston... 49 Fuel Injection Lines................................... 46 Fuel Setting Procedure................................ 54 Fuel System Inspection... 42 Governor Adjustments... 59 Removal and Installation of Fuel Injection Pumps....... 47 Testing Fuel Injection Nozzles......................... 42 (Cont. next page) 3

3204 VEHICLE ENGINE INDEX TESTING AND ADJUSTING (Cont.) Fuel System (Earlier & Later)...................... 62 Governor Adjustments... 84 Adjustment and Cleaning of 9L6969 Fuel Injection Pump (Install) (Earlier)....................... 99 Injection Nozzles... 69 Injection Pump (Remove) (Earlier)........ 98 Adjustment and Cleaning of 9N3979 and 1W5829 Injection Pump (Install) (Later)... 87 Fuel Injection Nozzles............................... 77 Injection Pump (Remove) (Later)... 87 Checking Engine Cylinders Separately................. 62 Setting Fuel Injection Pump Timing Checking Engine Timing with 6V3100 Dimension (Off Engine) (Earlier)... 108 Diesel Engine Timing Indicator Group (Later)... 92 Testing Capsule-Type Fuel Injection Engine Speed Measurement........................... 85 Nozzles for PC Engines... 80 Engine Timing (Dynamic Test) (Earlier)... 102 Testing 9L6969 Fuel Injection Finding Top Center Compression Position Nozzles For DI Engines... 63 For No.1 Piston (Earlier)... 101 Testing 9N3979 and 1W5829 Fuel Injection Finding Top Center Compression Position Nozzles For DI Engines... 71 For No.1 Piston (Later)... 89 Timing the Accessory Drive Shaft (Earlier)... 103 Flow Checking Fuel Injection Pump Timing Troubleshooting of 9L6969 Fuel DI Engines (Earlier)... 105 Injection Nozzles... 67 PC Engines (Earlier)... 106 Troubleshooting of 9N3979 and 1W5829 Fuel Fuel Injection Lines (Earlier)...,... 101 Injection Nozzles... 76 Fuel Injection Lines (Later)............................ 88 Fuel Injection Service...,.... 83 Electrical System... 127 Fuel Injection Timing Adjustment Alternator Regulator... 129 Off Engine (Later)... 94 Battery... 128 Fuel Injection Timing Adjustment Charging System... 128 On Engine (Later)................................... 93 Starting System... 129 Fuel Injection Timing Check (Fuel Test Tools For Electrical System... 127 Flow Method) (Later)................................ 90 Fuel Injection Timing Check (Timing Lubrication System... 117 Increased Oil Temperature... 118 Pin Method) (Later)... 90 Fuel Nozzle Test Sequence............................ 81 Measuring Engine Oil Pressure... 117 Fuel Pressure Control (Earlier)... 101 Oil Pressure is High... 118 Fuel Pressure Control (Later).......................... 89 Oil Pressure is Low... 118 Fuel Rack Setting (Earlier)... 110 Too Much Bearing Wear... 118 Too Much Oil Consumption...,... 117 Fuel Rack Setting (Later).............................. 96 Fuel System Adjustments (Off Engine) (Earlier)... 108 Fuel System Adjustments (On Engine) (Earlier)... 105 Troubleshooting........................................ 30 Fuel System Inspection... 62 SPECIFICATIONS NOTE: For Specifications with illustrations, make reference to SPECIFICA TIONS for 3204 VEHICULAR ENGINE, Form No. REGOI254. If the Specifications in Form REGOl254 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date. 4

D3 POWER TRAIN SPECI FICATIONS INTRODUCTION c The specifications given in this book are on the basis of information available at the time it was written. The specifications torques, pressures of operation, measurements, adjustments and other items can change at any time. These changes can effect the service given to the product. Get the complete and most current information before you start any job. Caterpillar Dealers have the most current information which is available. For a list of the most current modules and form numbers available for each Service Manual, see the SERVICE MANUAL CONTENTS MICROFICHE REG 1139F. When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is equal to or within the specification given, use the part again. When the word "permissible" is in the description, the specification given is the "maximum or minimum" tolerance permitted before adjustment, repair and/or new parts are needed. A comparison can be made between the measurements of a worn part, and the specifications of a new part to find the amount of wear. A part that is worn can be safe to use if an estimate of the remainder of its service life is good. If a short service life is expected, replace the part. 77200X2 NOTE: For Systems Operation and Testing and Adjusting, make reference to D3 TRACTOR POWER TRAIN, Form No. REG01262. c INDEX Bevel Gear and Pinion................................................... 10, 11 Bevel Gear and Pinion Shaft Free Movement (Backlash)... 12 Brake Adjustment........................................................... 14 Brake Drum Alignment... 13 Carrier Roller............................................................... 18 Control Group for Transmission Oil System.................................. 6 Control Linkage for Transmission... 9 Control Valve for Steering Clutch............................................ 8 Final Drive... 17 Final Drive Bearing Installation... 16 Front Idler and Recoil Spring... 18 Hydraulic Controls... 7 Lubrication Relief Valve..................................................... 8 Oil Pump for the Transmission.............................................. 4 Plugs for Steering Clutch Case.............................................. 17 Pressures for the Hydraulic Controls......................................... 7 Roll-Over Protective Structure (RaPS)....................................... 19 Steering Clutch... :... 15 Steering Clutch Adjustment... 15 Torque Converter........................................................... 6 Track... 21 Track Adjustment........................................................... 20 Track Rollers... :..................................................... 19 Transfer Gears... 5 Transmission............................................................... 5 Transmission and Governor Control (Attachment)............................ 9 Universal Joint... 8 Undercarriage Support...................................................... 19 Winch Drive... 19 NOTE: The "C" is an indication of a change from the former issue.?

03 POWER TRAIN INDEX SYSTEMS OPERATION Lubrication System for the Transmission..................................... 11 Power Flow... 5 Steering Clutches, Brakes and Final Drive... 15 Torque Converter and Transmission......................................... 6 Planetary Transmission... 6 Torque Converter......................................................... 6 Transmission Hydraulic Controls... 12 TESTING AND ADJUSTING Back-up Alarm... 23 Bevel Gear and Pinion (Adjustment).... Adjustment for the Amount of Free Movement (Backlash).... Bearing Preload of Bevel Gear Shaft.... Bevel Pinion Assembly.... Bevel Pinion Location.... Final Drive Installation.... Power Shift Transmission Testing and Adjusting... See Form No. REG01307 Problem Solving... 18 Check List During Operation... 18 Checks During Operation...... 18 Visual Checks... 18 Steering Clutches and Brakes............................................... 20 Brake Adjustment.... Brake Drum Alignment.................................................... 23 Brake Noise.............................................................. 23 Brake Pedal Kickback..................................................... 22 Rough Brake Operation..., 22 Slow Operation of Steering Clutches... 20 Steering Clutch Adjustment.... Track Adjustment.... Transmission Control Linkage.... Transmission and Governor Control.... 'See SPECIFICATIONS, Form No. REG01263 SPECIFICATIONS NOTE: For Specifications with illustrations, make reference to the POWER TRAIN SPECIFICATIONS FOR D3 TRACTOR, Form No. REG01263. If the Specifications in Form REG01263 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date. NOTE: The "C" is an indication of a change from the former issue. 3

POWER TRAIN DISASSEMBLY AND ASSEMBLY INDEX Battery And Frame Assembly... 105 Bevel Gear and Pinion... 55-60 Bucket (931)... 106 Dash Panel (D3)... 93,94 Drive Shaft... " 43 Drive Shaft, Disassemble & Assemble............................................... 43 Engine, Torque Converter And Transmission (D3).. Engine, Torque Converter And Transmission (931)... 61,62 63-67 Final Drive Pinions......................................................... 53, 54 Front Idlers... 23,24 Front Idlers, Disassemble & Assemble... 25-29 Fuel Tank.................................................................... 95 Hydraulic Control Valves........................................................ 96 Hydraulic Control Valves, Disassemble & Assemble................................. 97-100 Hydraulic Oil Pump... 101 Hydraulic Oil Pump, Disassemble & Assemble... 102, 103 Hydraulic Tank... " 108 Hydraulic Track Adjuster Seals... 30,31 Recoil Springs... 32, 33 Roll-Over Protective Structure (ROPS) Canopy... 104 Seat Assembly... 104 Sprockets.................................................................. 36-38 Sprocket Shaft, Gear And Cover... 39-42 Steering Clutches... 45,46 Steering Clutches, Disassemble & Assemble... 47-50 Steering Clutch Control Valves.................................................... 44 Steering Clutch Control Valves, Disassemble & Assemble................................ 44 Steering Clutch Hub Couplings And Pinion Flanges.......................... 51,52 Tilt and Lift Cylinders... 107 Torque Converter And Transmission... 69-72 Torque Converter And Transmission, Disassemble & Assemble... 78-89 Torque Converter And Transmission, Remove And Install From Case...................... 77 Torque Converter And Transmission, Remove And Install From Engine.................... 68 Tracks, Separation And Connection... 21, 22 Track Carrier Rollers... 7,8 Track Carrier Rollers, Disassemble & Assemble... 9-11 Track Rollers............................................................... 14-16 Track Rollers, Disassemble & Assemble... 17-20 Track Roller Frames... 34,35 Track Roller Guards... 12,13 Transfer Gears...... 90.92 Transmission Control Valve, Disassemble & Assemble... 75 Transmission Oil Pump, Disassemble & Assemble...................................... 76 Transmission Oil Pump And Control Valve... 73, 74 I!::::. WARNING DISCONNECT BATTERIES BEFORE PERFORMANCE OF ANY SERVICE WORK. 6

D3 TRACTOR HYDRAULICS INDEX SYSTEMS OPERATION Control Assembly... 6 Make-up Valve... 13 Relief Valve... 13 Ripper Hydraulics.... Valve Section for RAISE and LOWER.... F LOA T Position...................................... HOLD Position.... LOWE R Position........................................... RAISE Position.... Valve Section for Ripper in HOLD Position.... Valve Section for Ripper in LOWER Position.... RAISE Position.... Valve Section in ANGLE LEFT Position.... Valve Section in ANGLE RIGHT Position.... Valve Section in HOLD Position.... Valve Section in TI L T LEFT Position.... Valve Section in TI L T RIGHT Position.... 14 9 12 10 11 11 15 16 16 8 9 7 9 8 TESTING AND ADJUSTING Checking Pump Efficiency... 17 Test on the Bench... 18 Test on the Machine... 18 Performance Test List....................... 17 Relief Valves... 18 Relief Valve for Bulldozer....................................... 19 Relief Valve for Ripper... 19 Test for Drift of Cylinder Rods................................... 18 Lift Cylinders,............................................ 18 Visual Checks............................................... 17 SPECI FICATIONS NOTE: For Specifications with illustrations, make reference to the D3 TRACTOR HYDRAULICS SPECIFICATIONS, Form No. REG01265. If the Specifications in Form REGO 1265 are not the same as in the Systems Operation and the Testing and Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date. 3

D3 TRACTOR HYDRAULICS SYSTEMS OPERATION head end and rod end of cylinder (6). Relief valve ( 1) is in the passage to the head end of cylinder (6). The relief valve opens at approximately 3700 psi (260.1 kg/cm 2 ). Relief valve (1) in the hydraulic system is a protection for the tooth groups of ripper assembly (11). Ripper assembly (11) can move the rod up into cylinder (6), which opens relief valve (1), if the tooth group comes against material that can not be moved. Valve Section for Ripper in HOLD Position RIPPER 6. Ripper cylinder. 11. Ripper assembly. The pump oil from the other valve sections of the contwl assembly goes into passages (2), (4) and (6). When valve spool (5) is in HOLD position the oil in passages (2) and (4) goes around the valve spool and through passage (3). The oil in passage (3) goes to the end section of the control assembly and then through passage (1). Passage (1) is to the passages through all of the valve sections and the oil goes to the filter and tank. The HOLD position of valve spool (5) stops the oil in passages (7) and (9) to the cylinders. The cylinders can not move until the control lever for the ripper is moved to another position. When the ripper, in the ground, comes against a piece that will not move, the ripper moves up. As the ripper is moved up, the pressure of the oil in the head end of the cylinder gets an increase. Relief valve (10) opens to let the oil run out of the head end of the cylinder when the pressure of the oil is approximately 3700 psi (206.1 kg/cm 2 ). PUMP OIL TO TANK STOPPED OIL 6- ~:L6 7 73194XI VALVE SECTION IN HOLD POSITION 1. Passage to tank. 2. Passage from pump. 3. Passage to end section. 4. Passage from pump. 5. Valve spool. 6. Passage from pump. 7. Passage to rod end of the cylinder. 8. Check valve. 9. Passage to head end of the cylinder. 10. Relief valve. A. LOWER position. B. HOLD position. C. RAISE position. 15

TABLE OF CONTENTS Introduction 3 Equipment Installation......................................... 3 Preparation of System for Test................................... 3 System Test (Chart A)......................................... 3 Troubleshooting 5 6 Troubleshooting......................................... 7 Pump Test for Aeration and Cavitation... 7 Troubleshooting.................................. 7 Pump Test (Chart B)... Blocked Cylinders Test (Chart C)... 8 All Cylinders Blocked... 8 Troubleshooting...,..................... 9 Right Side Cylinders Blocked... 9 Troubleshooting.,....................................... 10 aeration: Air mixed with the oil. GLOSSARY block, blocking, blocked: To close off a passage; to stop or prevent movement. cavitation: Air present at the inlet of the pump. data: Specific information. flow differential (flow loss): The difference between two oil flows. stick, sticking, stuck: To prevent free movement; keep open or closed. tip, tipping, tipped: To move from a vertical position; to slope. viscosity: The property of a fluid that resists internal flow by releasing counteracting forces.

03 AND 931 BACKHOE INDEX SPECIFICATIONS Actuator for Boom Swing... 15 Cylinder for Stick............................ 16 Pump, Hydraulic (3G2873, 3G4096)............... 10 Control Valve (3G646).............................. 13 Pump, Hydraulic (8J4515, 3G5386)... 12 Control Valve (3G5634)... 14 Cylinder for Boom... 15 Servovalve (3G3710).......................... 11 Cylinder for Bucket.................................. 16 Servovalve (3G7421)... ;... 11 Cylinder for Stabilizer (Fixed Pivot)...................... 17 Cylinder for Stabilizer (Side Shift)... 17 Torque Chart... 7 SYSTEMS OPERATION Backhoe Hydraulic System........................... 18 Swing Actuator......................... 28 Control Valve for Backhoe... 20 Cushion Valve in Swing Actuator... 28 Valve Section for Boom, Stick and Swing... 24 Valve Section for Bucket in CLOSE Position... 23 Hydraulic Pump (Axial Piston-Type)... 26 Valve Section for Bucket in DUMP Position... 22 Valve Section for Bucket, Left and Right Stabilizers... 20 Relief Valves... 25 Valve Section for Swing in SWING RIGHT Position... 24 TESTING AND ADJUSTING Backhoe Hydraulic System........................... 30 Relief Valve Adjustment... 35 Relief Valve Test... 34 Checking Pump Efficiency... 30 Servovalve Adjustment............................. 33 Hydraulic Pump (Axial Piston-Type)... 32 Servovalve Pressure Test... 32 Oil Leakage Test for Axial Piston-Type Pump... 35 Tests for Drifts of Cylinder Rods... 31 Operation Times... 31 Stabilizer Cylinders... 31 Stick and Boom Cylinders... 31 Performance Test List... 30 Too Much Cylinder Rod Drift... 31 Relief Valves... 34 Visual Checks..................................... 30 DISASSEMBLY AND ASSEMBLY Index for Disassembly and Assembly.................. 37 5

D3 AND 931 BACKHOE DISASSEMBLY AND ASSEMBLY INDEX Backhoe Stabilizers... 77 Boom and Boom Cylinder...... 42-46 Boom, Disassemble & Assemble... 47,48 Bucket (Backhoe)... 39 Bucket Cylinder... 49,50 Bucket Linkage... 40 Console... 78-81 Frame............................................. 88,89 Hoe Stick............ 41 Hydraulic Control Valves... 82-87 Hydraulic Cylinders, Disassemble & Assemble......... 56-62 Piston Hydraulic Pump...... 90-93 Piston Hydraulic Pump, Disassemble & Assemble......... 94-104 Stabilizer Cylinder... 54,55 Stick Cylinder... 51-53 Swing Actuator...... 63-64 Swing Actuator, Disassemble & Assemble... 65-72 Swing Frame... 73-75 Swing Frame, Disassemble & Assemble... 76 Tips and Sidecutters... 38 37

03,910 & 931 HYDRAULICS SPECI FICATIONS INTRODUCTION The specifications given in this book are on the basis of information available at the time the book was written. These specifications give the torques, operating pressure, measurements of new parts, adjustments and other items that will affect the service of the product. When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is equal to or within the specification given, use the part again. When the word "permissible" is in the description, the specification given is the "maximum or minimum" tolerance permitted before adjustment, repair and/or new parts are needed. A comparison can be made between the measurements of a worn part, and the specifications of a new part to find the amount of wear. A part that is worn can be safe to use if an estimate of the remainder of its service life is good. If a short service life is expected, replace the part. NOTE: The specifications given for "use again" and "permissible" are intended for guidance only and Caterpillar Tractor Co. hereby expressly denies and excludes any representation, warranty or implied warranty of the reuse of any component. 77200X1 NOTE: For Systems Operation and Testing and Adjusting, make reference to: D3 Tractor Hydraulics, Form No. REG01264. 910 Loader Hydraulic System, Form No. REG01225. 931 Loader Hydraulic System, Fonn No. REG01328. INDEX Control Lever Linkage................................................. 11 Control Valve Assembly................................................ 8 Cylinders.:... 9, 10 Hydraulic Pump.................................................... 6, 7 Lines, Plugs and Fittings................................................ 4 Assembly of Fittings With Straight Threads and O Ring Seals................. 4 Line Installation... 4 Torque for Flared and O-Ring Fittings... 4 Torque for Other Fittings... 5 Oil Filter... 11 Relief Valve Adjustment... 8 Tilt Levers... 11 2