Description

Komatsu BR300J-1, BR310JG-1 1995 Workshop Manual

You have a Komatsu BR300J-1 or BR310JG-1 that won’t crush right, or the feeder stalls under load. Before you start pulling hydraulics apart with a generic PDF you found on some forum, stop. I’ve seen what happens when techs guess on hydraulic pressures or valve clearances – blown seals, ruined pumps, and a machine that sits dead for a week. This Komatsu BR300J-1, BR310JG-1 1995 Workshop Manual from AutoRepairManuals is what the factory handed to their own guys. Not a reprint. Not a third-party copy. Original OEM print, scanned from the binder.

7 Systems Covered in This Factory Manual

You get the full breakdown. Section 10 – STRUCTURE AND FUNCTION walks you through the power train, track frame, final drive, hydraulic pump (front and rear main pump HPV090+090), servo valve, TVC valve, CO·NC valve, charging pump, control valve, crusher motor, travel motor, PPC valve, accumulator, solenoid valves for crusher/belt conveyor/travel, tandem pump, hydraulic 3-tandem pump, plate feeder motor, first belt conveyor motor, relief valves, flow control valve, crusher, plate feeder, grizzly feeder, belt conveyor, and the complete monitor system with sensors. The monitor system alone – including the plate feeder pressure sensor, timer, feeder automatic reverse system, and automatic stop for conveyor overload – is worth the price of the manual if you’ve ever had a feeder jam and had to guess which sensor failed.

Valve Clearance and Hydraulic Pressure: Factory Only Data

Section 20 – TESTING AND ADJUSTING begins with a TABLE OF JUDGEMENT STANDARD VALUE. If you need to set valve clearance on the SA6D95L engine, you go there. The procedure for ADJUSTING VALVE CLEARANCE is spelled out with the exact feeler gauge thickness and tightening sequence. No “tighten until it feels right.” The manual also covers MEASURING COMPRESSION PRESSURE, TESTING AND ADJUSTING FUEL INJECTION TIMING, and ADJUSTING FUEL CONTROL LEVER. For hydraulics, you get the specific pressure specs for crusher, plate feeder (BR300J-1), grizzly feeder (BR310JG-1), belt conveyor, travel circuit, charging pump pressure, main pump control pressure, servo piston stroke, travel deviation, PPC valve output pressure, crusher adjustment, and tandem pump belt tension. I’ve used these specs to save a machine that a previous shop had misadjusted by 150 psi – the crusher ripped itself apart inside. This manual gives you the numbers that prevent that.

20 Testing and Adjusting: The Real Meat

Beyond basic adjustments, this section includes AIR BLEEDING and RELEASING REMAINING PRESSURE IN HYDRAULIC CIRCUIT – a step beginners ignore because they don’t have a manual telling them to crack the relief valve first. The troubleshooting portion is divided into electrical (E mode) and hydraulic/mechanical (H mode). E-mode has fourteen specific fault paths: E-1 through E-13 cover engine stall, crusher not actuating, crusher not reversing, belt conveyor issues, feeder not switching to reverse, magnetic separator problems, horn failure, travel lock release faults. Each path gives connector types, mounting locations, and a connection table. This is not a generic wiring diagram; it’s machine-specific. The H-mode section covers seven fault conditions: slow speeds, engine drop, no movement, lack of power, abnormal pump noise, slow crusher turning, slow plate feeder. Pair this manual with a copy of the Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual if you also work on wheel loaders – same hydraulic logic, different machine.

Why Factory OEM Trumps Aftermarket Reprints

I won’t mince words: aftermarket manuals for Komatsu crushers are garbage for these machines. They copy the diagrams but leave out the judgment table values, torque specs for the final drive bolts, and the exact sequence for bleeding the OLSS system. This document is the original 1995 Komatsu shop manual, 367 pages, published by Komatsu themselves. Every torque value, every hydraulic pressure, every electrical pinout is as it left the factory. You don’t get a reprint that blurred a critical number. You get the source. For comparison, see the Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual which covers more wheel excavators but follows the same structure. If you need a purely hydraulic-focused reference for smaller machines, the Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs is also available.

Who Needs This Manual on Their Workbench

If you own a BR300J-1 or BR310JG-1 and do your own maintenance, this is the difference between swapping parts until it works and fixing it right the first time. Beginners: don’t attempt hydraulic pressure testing without this – you can damage the pump. Professional mechanics: you already know the value of having factory wiring diagrams and connector locations when a travel lock solenoid fails. This manual includes the complete ELECTRICAL CIRCUIT DIAGRAM (page 90-4) and HYDRAULIC CIRCUIT DIAGRAM (page 90-3). Whether you are a mobile crusher operator or a shop that services crushers for hire, this document pays for itself on the first job. Need to understand basic driveline theory? The Manual Transmission wikipedia article explains torque conversion, but this manual applies it to the crusher drive hydraulic circuit.

FAQ

What engine does the BR300J-1 use?

SA6D95L. This manual covers it in the TESTING AND ADJUSTING section, but for full tear-down you need the 95 Series Engine Shop Manual separately.

Does this manual cover electrical troubleshooting for the crusher reverse system?

Yes. E-mode troubleshooting includes E-3: CRUSHER DOES NOT REVERSE EVEN WHEN CRUSHER REVERSE SWITCH IS PRESSED. It walks you through connector checks and relay circuits. The wiring diagram covers the entire solenoid valve system for crusher, belt conveyor, and travel. If you have an intermittent reverse issue, start with the connector type and pinout table in that section. The manual also covers the feeder automatic reverse system and the work equipment self-hold circuit. That self-hold circuit is often the culprit when the crusher stays on after you release the switch – the manual shows exactly which relay and diode are involved, with resistance values. I’ve fixed three machines with that one diagram alone.

How many pages in this manual?

367 pages, including the 1995 revision list and both hydraulic and electrical circuit diagrams.

Can I adjust the grizzly feeder hydraulic pressure with this manual?

Yes. Section 20 includes TESTING AND ADJUSTING HYDRAULIC PRESSURE IN CRUSHER, PLATE FEEDER (BR300J-1), GRIZZLY FEEDER (BR310JG-1), BELT CONVEYOR, TRAVEL CIRCUIT. The pressure specs are in the JUDGEMENT TABLE. Do not attempt without a flow meter and the correct relief valve adjustment sequence.

If you work on older Komatsu wheel loaders, the Manual Transmission article on Wikipedia provides general background, but for your crusher, you need the real deal. Get the factory data. Access the Factory Manual from AutoRepairManuals and put it on your shop tablet or print the sections you need. One correct torque on a final drive bolt or one accurate pressure adjustment will save you more than the cost of the manual.