TURBO GP-BASIC 20R3766 - Caterpillar

is starting to use graphic or I.S.O. (International Standards Organization) symbols in most machine hydraulic schematics for new model releases. During the "phase-in" period, some schematics will still use the pictorial type of symbols that have been used in the past. However, all machine hydraulic schematics will eventually use ISO symbols. Cross sections of individual components will still be used in the descriptions of component operation.
Due to the worldwide usage of service literature and the increasing complexity of components, ISO symbols are being recognized as a means of providing more useful and cost effective serviceability to dealer people.
To date, dealer personnel who have been exposed to ISO symbols in training classes have given favorable responses. They have commented that it is easier to understand the overall system and to troubleshoot the system.
It is recommended that the following training material be used to familiarize dealer servicemen with ISO symbols and their usage.
... Service Training Meeting Guide, Graphic Fluid Power Symbols, SESV1546
... Fluid Power Graphic Symbols and Data, SEEV0529