John Deere 15 and 25 Excavator Technical Manual TM1385

What's Covered in This Manual

This is the official John Deere TM1385 Technical Manual for the 15 and 25 Excavators, published in October 1986. These are compact mini excavators, each powered by a different Yanmar diesel engine - the Model 15 runs the Yanmar 3TNA72-UJB while the Model 25 runs the larger Yanmar 3TN78-RJB - and this single manual documents both machines together, with each engine's specific removal, repair, and specification details called out separately.

For complete repair information on the Yanmar engines themselves, the manual directs the technician to the engine's own dedicated repair section within this manual covering engine removal, while the full internal engine rebuild procedures are referenced alongside the machine-specific installation and accessory service. Beyond the engine, the manual covers the hydraulic system - pumps, valves, cylinders, and the boom, arm, and bucket circuits - along with the undercarriage, travel motors, swing system, and electrical system shared across both excavator sizes.

Because the 15 and 25 share a common chassis design and hydraulic architecture while differing primarily in engine size and corresponding hydraulic output, this manual lets a technician service either model from one reference, following the model-specific specification tables and engine sections that apply to the machine actually in the shop.

These compact excavators were built for tight-access digging work, and their small-displacement Yanmar diesel engines along with their hydraulic circuits require careful attention to the specific torque values and wear tolerances this manual provides - a generic repair approach on a machine this size can easily lead to a leak or a premature component failure. This manual gives the exact factory figures needed to avoid that.

Table of Contents

• Introduction - Safety, California Proposition 65 warning
• Engine - Yanmar 3TNA72-UJB (Model 15) and Yanmar 3TN78-RJB (Model 25) removal and repair
• Hydraulic System - Pumps, valves, cylinders, boom/arm/bucket circuits
• Undercarriage - Travel motors, tracks, swing system
• Electrical - Wiring and component service