Komatsu WA150-1-A(S/N 10001-UP)

The Komatsu WA150-1-A (S/N 10001-UP) is a compact, four-wheel-drive articulated wheel loader built from 1987 to 1991. It runs a Komatsu S6D95L-1B six-cylinder diesel with a fully mechanical, jerk-type injection pump and no electronic engine management, so there are no alphanumeric fault codes - the operator gets lamp and buzzer warnings only. Operating weight sits in the roughly 7.5-7.6 t class, and the machine came from the factory with a Z-bar loader linkage able to carry a general-purpose bucket along with other front-end configurations such as forks, sized for site, yard, and municipal work rather than large-scale production loading. It sits early in Komatsu's long-running WA150 nameplate, ahead of the base WA150 built through the 1990s and the later WA150-5, WA150L-5, and WA150PZ-5 generation machines.

Across the WA150 nameplate, Komatsu moved from this early, all-mechanical -1-A generation toward electronically managed engines, in-cab monitor panels, and eventually load-sensing hydraulic and hydrostatic-influenced systems on later -5 and -6 generation loaders. That later electronics and diagnostics layer does not exist on the WA150-1-A, and it should not be assumed present when servicing or troubleshooting this serial range. In today's used and parts market, that mechanical simplicity is exactly why this generation still circulates: no control modules or sensors to fail, injection and governor work a competent diesel shop can still handle without a scan tool, and a parts base shared with other S6D95-family Komatsu machines of the same era. It remains a practical, low-cost entry point for buyers who want a small loader they can maintain and rebuild without electronic diagnostic equipment.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.