Yale MR14 MR16 MR16N MR16HD MR20 MR20HD MR25 Retractable Truck Service Manual – D849 PDF Workshop Guide

Description

Yale MR-Series Retractable Truck Service Manual – Document D849 (550066261)

This is the service manual used across the Yale retractable truck range – MR14, MR16, MR16N, MR16HD, MR20, MR20HD and MR25. It is a specialized technical document compiled for trained service personnel working on these three-phase AC electric retractable trucks, and covers the electrical architecture (VCM, ACE2 Traction, ACE2 Pump, EPS ACW modules), diagnostics and alarm handling, hydraulic functions, installation and adjustment procedures, and the mechanical assemblies that make up the truck base and mast.

File Details

• Manual type: Service Manual (specialized technician reference)
• Brand: Yale
• Document number: D849 – 550066261
• Covered models: MR14, MR16, MR16N, MR16HD, MR20, MR20HD, MR25
• Language: English
• File format: PDF
• Page count: 230 pages
• System voltage: 48V (battery-powered AC electric)
• Manufacturer location shown on plate: Made in Italy (Yale Europe, Surrey, United Kingdom)

Chapters Covered

The manual opens with a numbered section index using black bands for quick navigation. The top-level sections are:

• Section 1: Presentation
• Section 2: Installation and settings
• Section 3: Diagnostics and measurements
• Section 4: Electrical system
• Section 5: Hydraulic system
• Section 6: Truck base mechanics
• Section 7: Mast assembly mechanics
• Section 8: Small fork mast mechanics
• Section 9: Reduction gear
• Section 10: Braking system
• Section 11: Standard maintenance

Presentation and General Specifications

The presentation section describes the MR-series retractable truck range: seven models with nominal load capacities from 1400 kg to 2500 kg. It introduces the three-phase AC technology used across the traction motor, steering motor and pump motor, the 14 kW pump motor, the CAN-Bus architecture with two independent lines, and the regenerative inversion and release braking system. The general specifications tables then give dimensional and performance data for each model – wheelbase, turning radius (Wa), lifting height h3, free lift h2, mast heights h1/h4/h6/h7/h8, traction speeds, lifting and lowering speeds, battery voltage/capacity, and VDI-cycle consumption figures. A dedicated batteries table cross-references DIN 43531/35/36 A, B and C battery types with weight and capacity data.

Installation, Settings and Battery Setup

Installation coverage opens with weight tables for the truck base, mast assemblies and retractable carriage, followed by the materials list received from the dealer. Procedures walk through unloading from transport, fitting the mast to the truck base (torque figures of 88–97 Nm for side blocks and 300–330 Nm for the mast-to-base bolts), topping up the hydraulic oil reservoir, and two battery installation methods (vertical removal and lateral removal using a spreader bar and rollerway). The settings chapter closes with a checklist covering ACE2 Traction and ACE2 Pump module battery voltage setting, checking the conditions of use of the truck, verifying contrast roller movement along the aisle (max tolerance 5 mm on one side), enabling level pre-selector, programming middle fork lifting blocks, and programming operator passwords.

Diagnostics and Measurements

This section is built around the Zapi ACE2 diagnostic architecture. It covers the ACE2 Traction module, ACE2 Pump module, EPS ACW module, and the VCM Master control card. The TESTER menu documentation lists the live readings available from each module – battery voltage, working hours, fork height, steer angle, lift/low/reach/tilt/side shift potentiometer values, encoder pulses, pump RPM, digital and analog input levels, and output group percentages. The alarm sections are extensive: each alarm is listed with its programmer message, SICOS message, description, effect, truck state, and restart procedure. The troubleshooting matrix covers each alarm with a breakdown search – from watchdog and EEPROM errors through to encoder faults, contactor failures, thermal protection, field orientation errors and CAN communication loss.

Electrical System

The electrical system section includes component reference tables (A1 through T2), a full pinout for the VCM and ACE2 modules, and complete electrical wiring diagrams showing the 48V battery feed, CAN-Bus lines (Can Low 1/2 and Can High 1/2), key relay circuits, contactor wiring, horn, flasher, work lights, DC/DC converters, and the optional cold store cab application. Module replacement procedures are documented step by step for the ACE2 Inverter, EPS ACW and VCM modules, including the resistor discharge method (33–100 Ohm, 50W) and the operating-hours acquisition process that runs on ignition. Component-level replacement procedures cover the encoder, encoder reset sensor, load cell, horn, contactors, fuses (F1 through F6), motor compartment cooling fan, armrest and main panel controls, side shift position sensor, pallet presence sensor, tilt position sensor, 90° wheel sensor, steered wheel sensor, battery-out sensor, and the accelerator and brake pedals.

Hydraulic and Truck Functions

The truck functions portion of the manual documents the forward/reverse traction controls, speed reduction logic (cutback speed and cutback speed 2), deceleration with steering traction wheel, deceleration with low battery, traction blocks tied to seat and seat belt sensors, and the four braking systems (release braking, braking on direction reversal, emergency braking, parking brake). Hydraulic function chapters cover fork lifting/lowering controls, retractable carriage acceleration/deceleration ramps, carriage out/return limit stop slowdown, auxiliary function ramps, and fork self-centring. A parameter chapter lists the configuration parameters that can be accessed, searched and modified via the programmer, with the standard factory configuration for the VCM, ACE2 Traction, ACE2 Pump and EPS ACW modules.

Why this Yale D849 service manual matters

The MR-series retractable truck runs on a networked control architecture – VCM, ACE2 Traction, ACE2 Pump and EPS ACW – with two separate CAN-Bus lines and a Zapi-based diagnostic layer. Diagnosing a fault without the exact alarm code mapping, the correct TESTER reading, and the specific module pinout is guesswork. This manual puts those three things in one place: the alarm message, the effect on the truck, and the restart procedure, alongside the wiring diagrams needed to trace the circuit back to the source.

For the mechanical side, the manual gives the torque values that make the mast-to-base coupling safe, the sequence for fitting side blocks and tightening the mast bolts to 300–330 Nm, and the correct procedure for contrast roller setup that keeps aisle travel within the 5 mm tolerance. The hydraulic function chapters document the ramp behaviour that governs lift, reach, tilt and side shift – so a truck that is jerky, slow to respond, or dropping speed unexpectedly can be traced back to a configurable parameter rather than treated as a mechanical fault.

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Instant PDF delivery – no shipping, no waiting

This Yale MR14 MR16 MR16N MR16HD MR20 MR20HD MR25 service manual is delivered as a downloadable PDF immediately after checkout. There is no printed copy, no courier, and no waiting for a disc to arrive. The file opens on any device – laptop, tablet, or workshop terminal – and can be printed page by page for the jobs that need a hard copy on the bench. Keep it on the workshop PC for reference, or load it onto a rugged tablet and take the exact procedure, torque value and alarm code straight to the truck.