BOMAG BW 100 AD/AC Series 4 / BW 120 AD/AC Series 4 Service Training Manual (P/N 008 099 86)

• Covers the BOMAG BW 100 AD-4, BW 100 AC-4, BW 120 AD-4, and BW 120 AC-4 Series 4 rollers introduced in 2004; factory Service Training P/N 008 099 86, status 03/2004, in a 118-page PDF.
• Includes Kubota D 1703 MDI engine component views, compression testing, cold valve-clearance inspection and adjustment, engine troubleshooting charts, and diagnosis of the energized-to-run shutoff solenoid.
• Explains the Hydromatik A10 VG 28 travel pump, servo control, charge and high-pressure protection, Poclain MK04 drum motors, AC-only MSE02 wheel motors, parking-brake release, no-drive diagnosis, travel-power checks, and pump neutral adjustment.
• Details the Bosch gear-pump vibration circuit, AD and AC motor arrangements, control and brake valves, pressure and leakage testing, exciter-shaft checks, and electrical diagnosis for a no-vibration condition.
• Covers the Bosch steering/charge pump, Danfoss OSPC 80 ON steering valve, steering cylinder, articulated joint, and isolation tests used to distinguish cylinder, pump, and Orbitrol faults.
• Provides the Series 4 electrical drawing set 880 100 51, module pin and LED diagnostic data, component-location views, and separate full-machine hydraulic schematics for the AD and AC configurations.

This BOMAG factory training publication was prepared for service engineers and is best suited to professional technicians already familiar with hydraulic pressure testing, electrical measurements, and diesel-engine service equipment. Its emphasis is system operation, adjustment, fault isolation, and repair decisions rather than basic workshop instruction.

Series 4 Configuration Differences

The AD machines use two driven drums, with a vibration motor on each drum and a shutoff valve that permits front-drum-only vibration. The AC combination rollers pair a vibrating front drum with two hydraulically driven rear wheels. Their Poclain MSE02 wheel motors use oil-immersed multi-disc parking brakes, while the MK04 drum motors use Hirth-type brakes.

Sprinkler coverage distinguishes the standard gravity-fed water system from the optional pressure system. The AC configuration also includes an emulsion pressure-sprinkler circuit for the rubber tires. Component and circuit descriptions show how these systems interact with the travel-lever position, electrical control module, pumps, valves, and machine safety logic.

Factory Diagnostic Coverage

Travel-system troubleshooting follows a structured path from brake-valve voltage and current checks through charge pressure, relief valves, pump control chambers, individual motors, and brake circuits. Separate procedures address a machine that will not move, insufficient travel power, worn or misadjusted travel controls, and a roller that creeps with the lever in neutral. The manual also covers the different brake-release arrangements used on AD and AC machines.

Vibration diagnosis works from engine and exciter speed through circuit pressure, control-valve operation, pump output, motor leakage, and exciter-shaft bearing condition. Steering tests separate a defective cylinder from a weak steering/charge pump or faulty steering valve.

The electrical chapters go beyond basic wiring. They document the travel-lever monitoring module P/N 880 255 02 and seat-contact module P/N 88003042, including connector assignments, status LEDs, automatic angle-sensor zeroing, sensor-fault indication, seat and brake interlocks, manual and automatic vibration control, and sprinkler timing logic. Named Series 4 sheets cover supply/engine starting/emergency shutdown, vibration and sprinklers, brake and flow-divider circuits, seat contact, lighting, weather-protection cab equipment, and central electrics.

Two large-format hydraulic schematics identify the pumps, motors, valves, filters, cooler, test ports, brake circuits, and steering components in the AD and AC layouts. The PDF also carries a separately labeled legacy electrical appendix for BW 100/120 AD/AC-3, BW 125 ADH/ACH, and BW 135-138 AD/AC machines; that appendix does not extend the Series 4 mechanical repair coverage to those models.

Scope and Repair Cautions

The Kubota section supplies testing, adjustment, and fault-finding information but is not a complete internal engine-overhaul manual. BOMAG lists the operating and maintenance instructions, spare-parts catalog, separate repair instructions, and Service Information as additional publications.

The valve-clearance section warns that the flywheel TC mark applies only to cylinder No. 1. Using it as the index for the remaining cylinders can produce incorrect valve lash and risk valve-train damage. The travel-pump pressure check is a deliberately brief dead-head test; extending it beyond the manual’s limit can overload the pump and relief components.

Several procedures involve high-pressure hydraulics, mechanically released parking brakes, or a disabled drive circuit. The roller must be secured, hydraulic pressure relieved where specified, and the factory test limits followed before lines or safety devices are disturbed.