Complete digital official shop manual contains service, maintenance, and troubleshooting information for the Case 621B, 721B Loaders. Diagnostic and repair procedures are covered in great detail to repair, maintain, rebuild, refurbish or restore your Case 621B, 721B Loaders like a professional mechanic in local service/repair workshop. This cost-effective quality manual is 100% complete and intact as should be without any missing pages. It is the same factory shop manual used by dealers that guaranteed to be fully functional to save your precious time.

This manual for Case 621B, 721B Loaders is divided into different sections. Each section covers a specific component or system and, in addition to the standard service procedures, includes disassembling, inspecting, and assembling instructions. A table of contents is placed at the beginning of each section. Pages are easily found by category, and each page is expandable for great detail. It is in the cross-platform PDF document format so that it works like a charm on all kinds of devices. You do not need to be skilled with a computer to use the manual.

1,860 pages, bookmarked, Searchable, Printable, high quality PDF

621B, 721B Loaders Service Manual.pdf
621 B 6T-590; 721 B 6T-830

MODELS Covered

Case 621B 721B loader

621B 6T-590 Engine
721B 6T-830 Engine

SECTIONS covered

    General
    Loctite Product Chart
    Standard Torque Specifications
    Fluids and Lubricants
    Engines
    Engine Removal and Installation and Radiator Removal and Installation – 621B
    Engine Removal and Installation and Radiator Removal and Installation – 721B
    Stall Tests

        621B 6T-590 Engine
        Specification Details
        Cylinder Head and Valve Train
        Cylinder Block – Crankshaft, Pistons, Rods, Sleeves, Camshaft,
        Bearings, Seals, and Flywheel
        Lubrication System
        Cooling System
        Turbocharger
        721B 6T-830 Engine
        Specification Details
        Cylinder Head and Valve Train
        Cylinder Block – Crankshaft, Pistons, Rods, Sleeves, Camshaft,
        Bearings, Seals, and Flywheel
        Lubrication System
        Cooling System
        Turbocharger
        Turbocharger Failure Analysis
    Fuel System
        621B 6T-590 Engine
        Fuel System and Filters
        Fuel Injection Pump and Drive Gear
        Fuel Injectors
        721B 6T-830 Engine
        Fuel System and Filters
        Fuel Injection Pump and Drive Gear
        Fuel Injectors
        Description
    Electrical
    Removal and Installation of Starter and Alternator
    Electrical Schematics, Troubleshooting and
    Using Booster Batteries to Start the Engine
    Electrical Schematics and Troubleshooting – Units with Auto Shift Transmission
    Starter and Starter Solenoid – Nippondenso – 621B
    Starter and Starter Solenoid – Nippondenso – 721B
    Batteries
    Instrument Cluster and Gauges
    65 Ampere Alternator – Bosch
    Steering
    Removal and Installation of Steering Components
    Steering Specifications and Troubleshooting
    Steering Control Valve
    Flow Control Valve
    Steering Cylinder
    Center Pivot
    Auxiliary Steering Motor and Pump
    Power Train
    Removal and Installation of Power Train Components
    Transmission Specifications, Schematic, and Troubleshooting – Units Without Auto
    Shift Transmission
    Transmission Specifications, Schematic, and Troubleshooting – Units With Auto Shift
    Transmission
    Transmission Repair – 621B (4WG150)
    Transmission Repair – 721B (4WG180)
    Front and Rear Axle Repair
    Drive Shaft, Center Bearing and Universal Joints
    Wheels and Tires
    Transmission Control Valve – Units Without Auto Shift Transmission
    Transmission Control Valve – Units With Auto Shift Transmission
    Brakes
    Removal and installation of Brake Components
    Hydraulic Brake Troubleshooting
    Brake Pump
    Brake Accumulators
    Brake Actuator Valve
    Brake Accumulator Valve
    Parking Brake
    NOTE: For parking brake and brake pedal adjustments, see Section 9009.
    Hydraulics
    Removal and Installation of Hydraulic Components
    Hydraulic Specifications, Schematics. Troubleshooting and Pressure Checks
    Cleaning the Hydraulic System
    Hydraulic Pump
    Loader Control Valve
    Cylinders
    Coupler Lock Valve • XT Loader
    Remote Control Valves
    Pressure Reductng’Sequence Valve
    Chassis
    Air Conditioning Troubleshooting and System Checks
    Air Conditioning Troubleshooting and System Checks – For Systems with HFC-134a
    Refrigerant
    Air Conditioner System Service • Refrigerant Recovery,
    System Evacuation and Recharging
    Air Conditioner System Service • Refrigerant Recovery, System Evacuation and
    Recharging for Systems with HFC-134a Refrigerant
    Removal and Installation of Air Conditioning Components
    Removal and Installation of Air Conditioning Components – For Systems with
    HFC-134a Refrigerant
    Air Conditioning Compressor and Clutch
    Air Conditioning Compressor and Clutch – For Systems with HFC-134a Refrigerant
    Loader
    ROPS Cab and ROPS Canopy
    Seat and Seat Belts
    Suspension Seat
    Pedals and Levers
    Cab Window Replacement

EXCERPT:

STEP 80
Measure the cylinder sleeve bore for taper as follows:
1. Measure the bore parallel to the crankshaft at the top end of the ring travel zone.
2. Measure the bore in the same position at the bottom end of the ring travel zone.
3. Measure the bore at right angles to the crankshaft at the top end of the ring travel zone.
4. Measure the bore in the same position at the bottom end of the travel zone.
Compare the results of the measurements (1) and (3) with (2) and (4), to find out if the bore has taper. To measure use a inside micrometer, bore gauge or taper gauge. If the taper is more than 0.04 mm, the cylinder sleeve must be replaced.
STEP 81
Measure the cylinder sleeve bores for out-of-round as follows:
1. Measure the bore parallel to the crankshaft at the top end of the ring travel.
2. Measure the bore in the same position at the bottom end of the ring travel.
3. Measure the bore at right angles to the crankshaft at the top end of the ring travel.
4. Measure the bore in the same position at the bottom end of the ring travel.
Compare the measurements (1) and (3) to find the outof-round wear at the top end of the bore.
Compare the measurements (2) and (4) to find the outof-round wear at the bottom of the bore.
If out-of-round is more than 0.04 mm, the cylinder sleeve must be replaced.
Removing the Cylinder Sleeves
IMPORTANT: Cover the crankshaft journals with a clean cloth. Foreign material from the cylinder sleeve or the cylinder block will cause damage to the crankshaft.
STEP 82
Install a sleeve puller to remove the cylinder sleeve. Position the puller in the sleeve. Make sure that the jaws of the puller do not contact the four block lugs. Tighten the lock bar against the cylinder sleeve.
IMPORTANT: Make sure that the jaws of the sleeve puller do not contact the block lugs.
STEP 83
Carefully turn the bearing nut until the cylinder sleeve is loose from the cylinder block.
STEP 84
Remove the cylinder sleeve from the cylinder block.
Remove the a-ring from the cylinder sleeve.
...

Case 621B, 721B Loaders Workshop Repair & Service Manual