Caterpillar GC18 Forklift LPG Service Manual (99729-85100)

This Cat GC18 is an LPG counterbalanced forklift used for pallet work around warehouses, yards, and plant floors. When the truck has a gas-fuel problem, this is the workshop book a maintenance tech or independent shop reaches for. It helps you test, adjust, and repair the LPG system instead of guessing at fuel delivery faults. It is the LPG supplement published to pair with the engine service manual.

What this manual helps you do

• Trace the LPG tank, shutoff valve, and fuel lines
• Check the converter and regulator operation
• Adjust and diagnose the LPG mixer and fuel delivery system
• Pressure-test the gas system during fault finding
• Replace LPG system components using workshop procedures

Who this is for

This suits warehouse maintenance techs, dealer technicians, rental fleet mechanics, and independent forklift repair shops working on Cat GC18 trucks. It is for the gas-fuel side of the trade; the companion chassis manual, covering truck systems such as hydraulics, mast, steering, and wiring, is also available.

FAQ

Q: What do I receive, and how is it organized?

A: You receive 16 PDF files split by section, 79 pages total. The files are set up for printing and on-screen zooming, and the text layer lets you search and copy text.

Q: Will it fit my truck?

A: It covers the Caterpillar GC18 application with 4G63 engines, including the listed 4G63 and 4G64 references, plus 6G72 and the stated AA0001-ZZ9999 and 0A0001-0Z9999 coverage. Match those details to the truck before ordering.

Q: How does it fit the job?

A: Use it when diagnosing LPG fuel faults or servicing the tank, lines, converter, regulator, or mixer. That makes it the right book for gas-system work on this GC18.

If your truck matches the listed GC18 coverage, this manual gives your shop a direct LPG repair reference for testing and service work.

Models covered by this manual

Caterpillar publication 99729-85100 is the factory lpg service manual for the GC18. The same publication covers 6 further forklift models: GC15, GC20, GC20HP, GC25, GC25HP, GC30. The cover also lists 4G63, AA0001-ZZ9999, 4G64, 6G72, 0A0001-0Z9999, 4G63,. Check the model and serial number on your data plate before ordering.

Table of Contents:

• 99729-85100 – LPG Supplement Service Manual
  • Foreword
  • Types of LP-Gas
  • Structure and Function
  • Actions to Be Taken in the Event of a Failure
  • Pre CARB Troubleshooting
  • Pre CARB Disassembly and Reassembly
  • Pre CARB Inspection and Adjustment
  • CARB Tier 1 Emissions Control System
  • Systems Operation
  • System Adjustments
  • S-15G Fuel System Troubleshooting
  • Schematics
  • Inspection and Adjustment

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