3.7 Troubleshooting Operation Chassis z ( ): Always contact your KOMATSU distributor when deal- ing with these items. z In cases of abnormalities or causes which are not listed below, please contact your KOMATSU distributor for repairs. HST Axle Brake Parking brake 3-118 WA150-5H – VEAM934100 Problem Main causes Remedy Engine is running but machine does not move z Parking brake is applied z Directional lever is not shifted properly z No electricity is flowing to direc- tional lever (electrical type) z Lack of oil in hydraulic tank z Release parking brake z Shift lever properly z Check fuse and wiring harness connector z Add oil to specified level.
See EVERY 100 HOURS SER- VICE Even when engine is run at full throttle, machine only moves slowly and lacks power z Lack of oil in hydraulic tank z Hydraulic oil temperature is low z Add oil to specified level. See EVERY 100 HOURS SER- VICE z Carry out warming-up operation Oil overheats z Too much oil or too little oil z Clogged oil cooler core z Add or drain oil to specified level. See EVERY 100 HOURS SER- VICE z Clean oil cooler core Noise generated z Lack of transfer oil z Add oil to specified level. See WHEN REQUIRED Noise generated z Lack of oil z Improper oil used (for machines with limited-slip differential) z Add oil to specified level.
See WHEN REQUIRED z Change to specified oil Brake is not applied when pedal is depressed z Disc has reached wear limit z Defective hydraulic system Lack of oil Air in brake line z (Replace disc) z Add oil to specified level.
See EVERY 100 HOURS SER- VICE z (Bleed air) Brake drags or not applied z Defective adjustment of brake pedal linkage z Vent hole of brake valve is clogged z (Check, repair) z (Replace) z Clean Brakes squeal z Disc is worn z Large amount of water in axle oil z Deteriorated axle oil due to over- use of brake z (Replace disc) z Change axle oil z Change axle oil Poor braking effect z Linkage is loose z Disc is worn z Adjust z (Replace disc) Steering Steering wheel is heavy z Defective hydraulic system z Lack of oil z Add oil to specified level. See EVERY 100 HOURS SER- VICE