TYM T494HST T574HST Tractor Workshop Manual 2019 – Full PDF Repair Guide

Description

File Details

• Manual type: Tractor Workshop Manual
• Brand / Manufacturer: TYM (Tong Yang Moolsan Co., Ltd.)
• Models covered: T494HST / T574HST
• Engines covered: A2300N5 (T494), A2300T3 (T574)
• Language: English
• Page count: 241 pages
• File format: PDF
• Document number: 1387-960-001-0
• Edition: 1st Edition
• Publication date: September 2019

Chapters Covered

• Chapter 1. Introduction – safety, warning signs, ROPS and seat belt use, universal symbols, model and engine identification, specifications, gear train diagram, instruments, controls, filling and capacity table, maintenance chart
• Chapter 2. Disassembly and reassembly of major points – general precautions, standardised parts, operation chart, separation of front axle and bracket, engine and front axle bracket, engine and front transmission, front and spacer transmission, spacer and rear transmission, rear transmission and rear axle housing, rear transmission and cylinder case
• Chapter 3. Engine accessories – cooling system, radiator removal and inspection, air cleaner element, cleaning and installation
• Chapter 4. Clutch system – damper specification, HST unit specification, hydraulic hoses and lines, hydrostatic control linkage, hydrostatic system schematic, troubleshooting, diagnostics, hydrostatic pedal and neutral adjustment, pump pressure test, hydraulic bleed procedure
• Chapter 5. Transmission – wheel drive system, PTO drive system, specifications, HST system disassembly and reassembly, mid transmission, rear transmission, PTO clutch inspection, differential, shifting levers mechanism
• Chapter 6. Front axle (4WD) – centre pivot disassembly, inspection and reassembly, front differential, final case, troubleshooting
• Chapter 7. Rear axle and brakes – rear axle housing, wet multi-disc brake system, disassembly, inspection, reassembly, troubleshooting
• Chapter 8. Power steering system – gear pump, steering valve, oil tank, open centre non-load reaction function, disassembly, inspection and reassembly of the steering valve, special tools, troubleshooting
• Chapter 9. Hydraulic system – general description, specifications, disassembly and adjustment, link mechanism adjustment, main control valve, flow divider, pressure control valve, flow control valve, safety valve, relief valve, gear pump, filter, remote hydraulic control, troubleshooting
• Chapter 10. Electric accessories and instruments – battery inspection and charging, meters and switches, relay unit, fuse, controller, trailer socket, earthing point, wiring diagrams, troubleshooting
• Chapter 11. Cabin – instruments and related parts, controls, heating system, air conditioning system, cabin wiring instruction diagram and cabin wiring diagram
• Chapter 12. Service standard and other information
• Chapter 13. Conversion table – millimetres to inches, feet to metres, area, volume, mass, pressure, torque and temperature conversions

The TYM T494HST T574HST Tractor Workshop Manual is a 241-page service publication written for the technician who is tearing into the machine rather than just running it. It opens with the safety orientation material, then moves into the practical heart of the book: how the tractor splits apart at every joint that matters, how the HST and damper connect the engine to the transmission, and how each of the four main transmission cases comes apart and goes back together with the correct shimming, torque values and aligning marks. The document numbers its own figures heavily, so when you are standing under a separated tractor with a spread of bolts on the bench, you can match what you see to a numbered reference.

What Each Section Delivers in the Workshop

Engine, clutch and hydrostatic drive

The engine chapters and accessory sections cover the cooling system layout, radiator removal and pressure testing, the dry paper-element air cleaner with its dust unloading valve, and the maintenance intervals printed on the TYM chart. Chapter 4 is the HST chapter. It documents the damper flange that mounts on the flywheel and drives the HST input gear, lists the pump and motor displacement, swash plate angle, charge relief setting and oil cleanliness target, and walks you through the hydrostatic pedal and neutral adjustment with the turnbuckle. The forward and reverse pressure tests are spelled out with the port locations and the expected pressure values, and the hydraulic bleed procedure tells you how to clear trapped air out of the steering and rock shaft circuits.

Transmission, PTO, axles and brakes

The transmission section separates the front, mid, spacer and rear cases, and gives the tightening torques and stud bolt patterns for each joint. It covers the HST-to-mid case coupling, the sub-change and range gears, the 4WD drive gear with its V mark, the PTO input shaft and counter shaft, the hydraulically operated wet multi-disc PTO clutch, and the rear differential with the diff-lock. Front axle coverage takes the centre pivot apart, inspects the pivot metal bushes against their usable limits, rebuilds the front differential and the final drive cases, and gives you the toe-in and steering angle data. The rear axle and brake chapter breaks down the wet multi-disc mechanical brake, plate by plate, with thickness limits for the friction, separator and brake discs so you know exactly when to replace rather than measure again.

Hydraulics, steering, electrical and cabin

The hydraulic system chapter is one of the largest in the book. It covers the main control valve in neutral, lifting and lowering positions, the flow divider and its PTO solenoid valve, the pressure control valve that softens PTO clutch engagement, the slow-return check valve, the safety valve, the relief valve and the dual gear pump. It gives the tightening torques for the main valve, slow-return check valve and remote valve, plus the linkage adjustment dimensions for position and draft control. The power steering chapter rebuilds the orbitrol steering valve step by step using the special tools, with a troubleshooting table that starts from a heavy steering wheel and works through every likely fault. The electrical chapter covers battery testing, meter and switch checks, the controller pinout, the fuse box layout and the engine, main, rear and cabin wiring diagrams. The cabin chapter adds the heating and air conditioning systems, with R134a refrigerant charge data and a diagnostic pressure chart.

Service data and conversion tables

Specification data is spread throughout the book at the head of each chapter rather than gathered into a single appendix, so you read the capacities, pressures, torques and clearances alongside the procedure they belong to. The final chapter is a full conversion table set covering length, area, volume, mass, pressure, torque and temperature, which is useful when a torque wrench or gauge reads in units you do not habitually work in.

Why This Manual Matters on the Bench

Hydrostatic tractors like the T494HST and T574HST are not forgiving of guesswork. The HST unit runs on tight internal clearances, a fixed charge pressure and a specific oil cleanliness target; get the neutral adjustment wrong and the machine creeps in low range, get the shimming wrong in the rear transmission and the ring and pinion will not last. This manual gives you the values and the sequence to do the job properly, including the pre-loads, the aligning marks you must make before separating a case, the adhesive call-outs for each mating surface, and the check points to confirm after reassembly. Where the book wants a special tool, it shows the tool. Where a component can be inspected rather than replaced, it gives the usable limit. That combination is what turns a vague repair into a repeatable one.

Because the manual was written for the whole machine rather than a single sub-assembly, it also lets you follow a fault through the system instead of stopping at the first likely component. The hydrostatic troubleshooting chart, the power steering fault table, the rear axle and brake table and the hydraulic system table each start from a symptom and step through causes in order, which is exactly the way a diagnosis actually progresses in the shop.

IMAGES PREVIEW

Delivery is instant. Once payment clears, the PDF is available to download and open on a laptop, tablet or phone. There is nothing to ship and nothing to wait for. You can print the pages you need for the job at hand, or keep the whole file on a shop tablet and zoom into the exploded views and wiring diagrams as you work. If you own a T494HST or T574HST and intend to keep it running rather than pay someone else to guess, this is the reference to have on hand.