Gehl GE 803 Compact Excavator Repair Service Manual

Table of Content of the Gehl GE 803 Excavator Manual:

Operation
Important information about this service manual …………………………………………….. 1-1
Abbreviations/symbols ………………………………………………………………………………… 1-1
Identification of warnings and hazards ………………………………………………………….. 1-2
Designated use and exemption from liability ………………………………………………….. 1-2
Serial plates and component numbers ………………………………………………………….. 1-3
Serial number location ………………………………………………………………………………… 1-3
Engine number ………………………………………………………………………………………….. 1-3
Hydraulic pump identification number ……………………………………………………………. 1-4
Main valve block identification number ………………………………………………………….. 1-4
Travel drive identification number …………………………………………………………………. 1-4
Swivel unit identification number ………………………………………………………………….. 1-4
Machine: overview ……………………………………………………………………………………… 1-5
Cab overview …………………………………………………………………………………………….. 1-6
Cab legend ……………………………………………………………………………………………….. 1-7
Instrument panel overview …………………………………………………………………………… 1-8
Instrument panel legend ……………………………………………………………………………… 1-9
Engine compartment: overview ………………………………………………………………….. 1-10
Chassis: overview …………………………………………………………………………………….. 1-11
Tilting the cab ………………………………………………………………………………………….. 1-12
Tilting the cab up ……………………………………………………………………………………… 1-13
Tilting the cab down ………………………………………………………………………………….. 1-13
SAE operating controls (standard) ………………………………………………………………. 1-14
ISO operating controls (selectable) …………………………………………………………….. 1-15
Boom slew/auxiliary hydraulics pedal ………………………………………………………….. 1-16
Dozer blade …………………………………………………………………………………………….. 1-16
Throttle lever ……………………………………………………………………………………………. 1-17
Operator’s seat adjustments ………………………………………………………………………. 1-18
Ventilation ……………………………………………………………………………………………….. 1-20
Windshield ………………………………………………………………………………………………. 1-20
Cab door latch release ………………………………………………………………………………. 1-21
Interior light ……………………………………………………………………………………………… 1-21
Tool kit and cab jack handle ………………………………………………………………………. 1-21
Cab heat control ………………………………………………………………………………………. 1-22
Recirculated air mode ……………………………………………………………………………….. 1-22
Hydraulics/swiveling and boom rotation pedal adjustment ……………………………… 1-23
Battery master switch ……………………………………………………………………………….. 1-23
Specifications
Chassis …………………………………………………………………………………………………….. 2-1
Engine ………………………………………………………………………………………………………. 2-1
Hydraulic system ……………………………………………………………………………………….. 2-3
Undercarriage/swivel unit ……………………………………………………………………………. 2-4
Dozer blade ………………………………………………………………………………………………. 2-4
Electrical system ………………………………………………………………………………………… 2-5
Sound levels ………………………………………………………………………………………………. 2-7
Coolant compound table ……………………………………………………………………………… 2-7
Specific tightening torques …………………………………………………………………………… 2-7
General tightening torques ………………………………………………………………………….. 2-8
Dimensions ……………………………………………………………………………………………… 2-11
Lift capacities …………………………………………………………………………………………… 2-12
Lift capacity table (with extended dipper arm and counterweight) ……………………. 2-14
Geometry ………………………………………………………………………………………………… 2-15
Maintenance
General information care and servicing …………………………………………………………. 3-1
Care and servicing ……………………………………………………………………………………… 3-1
Maintenance safety …………………………………………………………………………………….. 3-2
Fluids and lubricants……………………………………………………………………………………. 3-3
Maintenance decal symbols …………………………………………………………………………. 3-5
Maintenance decal ……………………………………………………………………………………… 3-6
Maintenance schedule ………………………………………………………………………………… 3-7
General maintenance ………………………………………………………………………………… 3-10
Lubrication ………………………………………………………………………………………………. 3-12
Fuel system ……………………………………………………………………………………………… 3-13
Specific safety instructions …………………………………………………………………………. 3-13
Filling the fuel tank ……………………………………………………………………………………. 3-13
Fuel filter …………………………………………………………………………………………………. 3-14
Fuel shut-off valve, fuel prefilter and water separator …………………………………….. 3-14
Purging air from the fuel system …………………………………………………………………. 3-15
Engine lubrication system ………………………………………………………………………….. 3-16
Changing engine oil and filter …………………………………………………………………….. 3-16
Coolant system ………………………………………………………………………………………… 3-18
Checking coolant level ………………………………………………………………………………. 3-18
Air cleaner service ……………………………………………………………………………………. 3-19
Dust valve functional check ……………………………………………………………………….. 3-20
Checking and adjusting V-belt tension …………………………………………………………. 3-21
Checking and adjusting air conditioning V-belt tension ………………………………….. 3-22
Pressure check ………………………………………………………………………………………… 3-23
Test report ……………………………………………………………………………………………….. 3-28
Hydraulic system ………………………………………………………………………………………. 3-31
Checking hydraulic oil level ………………………………………………………………………… 3-31
Checking hydraulic pressure lines ………………………………………………………………. 3-35
Track system ……………………………………………………………………………………………. 3-36
Changing final drive oil ………………………………………………………………………………. 3-36
Electrical system ………………………………………………………………………………………. 3-39
Battery …………………………………………………………………………………………………….. 3-40
Using a booster battery (jump-starting) ………………………………………………………… 3-40
Cab heater filter ……………………………………………………………………………………….. 3-42
Engine
4TNV98 engine: overview ……………………………………………………………………………. 4-1
Fuel system ……………………………………………………………………………………………….. 4-3
Removing the cylinder head cover ………………………………………………………………… 4-4
Checking and adjusting valve tip clearance ……………………………………………………. 4-4
Cylinder head bolt tightening order ……………………………………………………………….. 4-6
Checking the injection nozzles ……………………………………………………………………… 4-6
Checking the nozzle jet ……………………………………………………………………………….. 4-7
Injection timing …………………………………………………………………………………………… 4-8
Adjusting engine RPM ………………………………………………………………………………… 4-9
Checking compression ………………………………………………………………………………… 4-9
Checking the coolant thermostat ………………………………………………………………… 4-10
Checking the thermal switch ………………………………………………………………………. 4-10
Oil pressure switch ……………………………………………………………………………………. 4-11
Checking the coolant circuit ……………………………………………………………………….. 4-11
Engine troubleshooting ……………………………………………………………………………… 4-12
Hydraulic system
Hydraulic pump ………………………………………………………………………………………….. 5-1
Main valve block ………………………………………………………………………………………… 5-6
Drive counterbalancing system …………………………………………………………………… 5-14
Boom summation — raise ………………………………………………………………………….. 5-16
Check valve (load retaining valve) ………………………………………………………………. 5-17
Dipper arm cylinder summation ………………………………………………………………….. 5-17
Dipper arm check valve (load retaining valve) ………………………………………………. 5-18
Secondary pressure limiting valves for the auxiliary hydraulics (option) …………… 5-19
Pilot valves ………………………………………………………………………………………………. 5-20
Valves …………………………………………………………………………………………………….. 5-25
Travel drive up to serial no. AC 02793 ………………………………………………………… 5-32
Travel drive Auto 2-speed (starting serial no. AC 02957) ……………………………….. 5-34
Swivel unit ……………………………………………………………………………………………….. 5-37
Swivel joint ………………………………………………………………………………………………. 5-42
Breather filter …………………………………………………………………………………………… 5-43
Troubleshooting the hydraulic system …………………………………………………………. 5-44
Hydraulic diagram (legend) ………………………………………………………………………… 5-46
Hydraulic diagram …………………………………………………………………………………….. 5-47
Main valve block diagram ………………………………………………………………………….. 5-48
Electrical system
Ohm’s law (current, voltage, resistance); power ……………………………………………… 6-1
Measuring equipment, measuring methods ……………………………………………………. 6-1
Cable color coding ……………………………………………………………………………………… 6-2
Relays ………………………………………………………………………………………………………. 6-3
Electrical units ……………………………………………………………………………………………. 6-3
Fuse box in instrument panel ……………………………………………………………………….. 6-3
Main fuse box with relays ……………………………………………………………………………. 6-4
Relays ………………………………………………………………………………………………………. 6-4
Lubrication strip accessory power socket ………………………………………………………. 6-5
Joystick tip switches …………………………………………………………………………………… 6-5
Instrument panel overview …………………………………………………………………………… 6-6
Switches: overview …………………………………………………………………………………….. 6-7
Alternator ………………………………………………………………………………………………….. 6-8
Starter ………………………………………………………………………………………………………. 6-8
Wiring diagram legend ………………………………………………………………………………. 6-10
Wiring diagram …………………………………………………………………………………………. 6-11
Wiring harness legend: engine—chassis ……………………………………………………… 6-12
Wiring harness: engine—chassis ……………………………………………………………….. 6-13
Wiring harness legend: switches ………………………………………………………………… 6-14
Wiring harness: switches …………………………………………………………………………… 6-15
Wiring harness: cab roof ……………………………………………………………………………. 6-16
Wiring harness: armrest …………………………………………………………………………….. 6-17
Wiring harness: boom working light …………………………………………………………….. 6-18
Options
Air conditioning ………………………………………………………………………………………….. 7-1
Counterweight ……………………………………………………………………………………………. 7-9
Extended dipper arm ………………………………………………………………………………….. 7-9
Control circuit hydraulic coupling connections ………………………………………………. 7-10
3rd control circuit connections ……………………………………………………………………. 7-10
Auxiliary hydraulics connections …………………………………………………………………. 7-11

This Service Manual is intended for Gehl GE 803 Excavator so as to give the owner/operator assistance in preparing, adjusting, maintaining and servicing the machine. More importantly, this manual provides an operating plan for safe and proper use of the machine. Major points of safe operation are
detailed in Chapter 2 – Safety. Read and understand the contents of this manual completely and become familiar with the machine before
attempting to operate it..

Throughout this manual, information is introduced by the word NOTE or IMPORTANT. Be sure to read the message carefully and comply with the message. Following this information will improve operating and maintenance efficiency, help to avoid breakdown and damage and extend the service life of the machine.