Komatsu PC88MR-10 Shop Manual page 19

When tightening nuts of the air conditioner
hoses and tubes, be sure to use 2 wrenches.
Use one wrench to fix and tighten the nut with
the other wrench to the specified torque (Use a
torque wrench for tightening).
a Example of fitting of O-ring
An O-ring is fitted to every joint of the air
conditioner piping.
For tightening torques, see "Others",
"Precautions for disconnection and connection
of air conditioner piping".
PC88MR-10
00 Index and foreword
Foreword, safety and general information
00-17