Hitachi LX160–LX450 and ZW220: engine systems and loader controls

LX engines and ZW controls: two different service paths

The LX160-7 and LX190-7 do not share an engine merely because their loader names sit next to each other. The factory service manual identifies an Isuzu BB-6HK1T in the LX160-7 and a Mitsubishi 6D24-TL in the LX190-7 and LX230-7. Its fuel-system description gives the Mitsubishi installation electronic governor and injection-timing control.

Electronic control alone does not make that pump system the same as the later ZW220's common-rail arrangement.

For the Mitsubishi-powered pair, the manual describes a linear motor moving the injection-pump rack and a timer valve changing injection timing. Two engine-speed sensors provide backup signals. A complaint about inconsistent speed therefore needs the engine identified before someone orders an Isuzu part or applies a ZW common-rail diagnosis.

The book directs engine-internal service to the engine maker's own manual; the loader's circuit diagrams remain necessary for the installation around it.

Steering coverage also splits by model. The service manual places the LX160-7 with the smaller-loader steering arrangement and gives the LX190-7/LX230-7 another section. Match the hydraulic diagram to the machine badge.

Copying a pressure or hose route from the adjacent size can miss that division even when the two machines have similar cab controls.

ZW220 work mode, shift mode and clutch cutoff are separate

The early ZW220 brochure gives work selection and travel selection different switches. Its work modes alter the engine/pump torque relationship. Its driving modes change shift timing: normal operation starts in second, the heavy-duty setting can downshift automatically into first under load, and the light-travel setting shifts earlier.

Record both switch positions before comparing two demonstrations of digging response.

Clutch cutoff adds another adjustment. The brochure describes different brake-pedal trigger points for level-ground loading and slope work. A transmission disengaging at a different pedal position can reflect that selected setting, so the operator should demonstrate the switch position before describing the response as a clutch fault.

Follow the machine's slope procedure; changing cutoff timing is not a substitute for it.

The ZW220's bucket return-to-dig function is distinct from optional lift-arm auto leveling. The latter can use programmed upper and lower positions; ride control is a separate option again. Ask to see each function operate.

The brochure's standard and optional equipment lists also separate variable-displacement implement/steering pumps from the gear pumps serving charging, cooling and brake assistance. A generic description of “the hydraulic pump” does not identify which circuit needs attention.