Bobcat 853 & 853H Skid-Steer Loader Service Manual – Complete PDF Workshop Guide

Description

This Bobcat 853 & 853H Service Manual (document number 6720755) is the complete shop-level repair guide for the 853 and 853H skid-steer loaders, covering the serial number groups listed on the cover from 508411001 through the later production runs. Published June 1999 and running 372 pages, this PDF gives technicians, fleet mechanics and owner-operators the procedures, specifications and diagrams needed to maintain, diagnose and rebuild these machines from the ground up.

File Details

• Manual Type: Service Manual
• Brand: Bobcat (Melroe Company)
• Models Covered: 853, 853H
• Language: English
• Page Count: 372
• File Format: PDF
• Document Number: 6720755
• Edition / Date: Printed June 1999

Chapters Covered

• Hydraulic System
• Hydrostatic System
• Drive System
• Main Frame
• Electrical System
• Engine Service
• System Analysis
• Specifications

Hydraulic System

Covers the full open-centre hydraulic circuit for the 853 and 853H loaders: lift and tilt cylinders, hydraulic control valve, main relief valve, front and rear auxiliary valves, bucket position valve, lock valve, hydraulic filter housing, hydraulic pump and reservoir. Includes checking the main relief setting (2550–2600 PSI at the quick couplers), pump output testing, lift and tilt cylinder checking and resealing, cylinder disassembly and assembly, control pedal adjustment, pedal interlock linkage and a full glossary of hydraulic and hydrostatic symbols used in the flow charts.

Hydrostatic System

Details the tandem hydrostatic pump and motor arrangement, including the replenishing and high-pressure relief valves, tow valves, charge pump, cold oil by-pass valve, hydrostatic charge oil filter, hydrostatic motor removal and installation, and the reduction gearcase — checking, disassembly, assembly and seal replacement. Steering lever adjustment is covered in depth: lever freeplay, steering neutral setting, neutral pre-adjustment, wheel RPM forward vs reverse, wheel RPM left vs right, and hydrostatic pump neutral adjustment. A dedicated troubleshooting chart handles no-drive, drifting, and overheat symptoms, with service code HP 2 information for BOSS-equipped machines.

Drive System

Includes final drive chaincase servicing, drive chain removal and installation, front and rear chaincase covers, axle seal replacement, axle, sprocket and bearing removal and installation using the axle bearing service set, parking brake adjustment and brake block, pad and disc service, and reduction gearcase overhaul. Correct torque values for axle hub bolts, axle sprocket bolts and wheel nuts are given throughout.

Main Frame

Operator cab removal and installation, cab gas cylinder disassembly and assembly, cab hold-down torque (40–50 ft.-lbs.), Bob-Tach removal and installation, Bob-Tach lever and wedge service, Bob-Tach stops, lift arm removal and installation, rear grill, rear door, hood, bumper, door latch adjustment, fuel tank and fuel level sender, and inlet screen service.

Electrical System

Battery removal, installation and jump-starting procedure; alternator output test, rectifier (diode) test, regulator test, alternator disassembly and assembly (Motorola or Prestolite 30 amp enclosed); starter checking, removal, disassembly, cleaning and inspection; standard instrument panel removal; front lights; steering lever control handle (early series). Full wiring schematics for both BOSS and non-BOSS 853 and 853H loaders are included, along with the BOSS diagnostic tool procedure, sender and sensor service values, and RPM sensor adjustment (0.050 inch clearance).

Engine Service

The largest chapter covers the Isuzu 4JB1 PK-03 four-cylinder diesel engine end to end: air cleaner housing, engine muffler, coolant recovery tank, radiator, fan drive tension pulley, fan gearbox / blower housing, fan gearbox backlash, engine removal and installation, flywheel and ring gear, belt shield, engine mounts, glow plugs, valve clearance adjustment (0.016 inch cold), engine compression testing, fuel injection pump description, removal and timing (17° BTDC), fuel injector nozzles and spray pattern, cylinder head removal and surfacing, valves, valve seats and guides, rocker arm and shaft, piston and connecting rod, cylinder liners, main bearings, crankshaft, timing gearcase cover and seal, idler gear and hub, fuel injection pump idler gear, camshaft gear, timing gearcase, camshaft, oil pan, oil pump, water pump, thermostat and water jacket tube.

System Analysis

Covers the BOSS (Bobcat Operation Sensing System) diagnostic tool procedure, sender and sensor electrical values, RPM sensor adjustment, the full monitor service code chart (ECL 1, EC 1.1 through EC 7, EP 1 through EP 7, ES 1 through ES 7, AF 2, AF 6, b-2.1, b-2.2, FUEL 2 through FUEL 7, HF1-2, HF1-6, HP 1 through HP 7, HC 1 through HC 7), the BOSS & LCD display troubleshooting chart, and BOSS unit and BOSS instrument panel removal and installation.

Specifications

Contains the complete loader specifications (operating weight 6497 lbs., rated operating capacity 1700 lbs., tipping load 3420 lbs., travel speed 0–6.3 MPH), engine specifications, hydraulic and hydrostatic fluid specifications, hydraulic connection tightening specifications for flare, O-ring face seal, O-ring flare, port seal and straight thread O-ring fittings, general SAE and metric bolt torque tables, loader torque specifications, decimal and millimetre equivalents, and U.S. to metric conversion charts.

What This Manual Lets You Do

With the Bobcat 853 service manual in hand you can pull fault codes from the BOSS system, test the hydraulic pump and set the main relief, reseal lift and tilt cylinders, tear down and rebuild the hydrostatic pump, replace final drive chains and axle bearings, set steering neutral and lever freeplay, adjust the parking brake, service the fan gearbox, remove and reinstall the engine, time the injection pump, set valve clearance, overhaul the cylinder head, and measure every wear limit and clearance the factory specifies. Every procedure is written for the technician who has to make the machine work again — not just read about it.

Why It Matters

Skid-steer loaders live in dirt, heat and vibration. A pump set 100 PSI off, a steering neutral that is not zeroed, a relief valve that will not hold, or a chaincase run low on oil will each cost a fortune in short order. This 853/853H repair manual gives you the correct torque values, clearances, pressures, flow rates and adjustment sequences so the job is done right the first time — whether you are a shop servicing a customer machine or an owner keeping a working loader alive.

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Instant PDF Delivery

The manual is delivered as an instant PDF download after payment. No shipping, no waiting, no physical book to lose in the shop. Open it on a laptop, tablet or phone, print only the pages you need for the job at hand, and keep the complete Bobcat 853 & 853H service manual on file for the next repair.