When hydraulic systems started to appear on agricultural equipment, manufacturers published service manuals with pictorials showing how each system operated. Pictorials do not work well with modern machinery because: •There too many hydraulic components on current agricultural machinery to be drawn in this style •Each pictorial needs to be duplicated several times to show how the components work in all working conditions and positions •The required text to describe how the system operated needed to be translated for technicians around the world The ISO schematic to the right represents a hydrostatic drive system similar to the text and pictorial above. A technician can use the drawing to the left and fully understand how the system works. The manufacturer’s explanation of how a hydraulic system functions can be done is a variety of ways: •Pictorial (above) •Text (right) •ISO Schematic (bellow) D r a w i n g I S O S c h e m a t i c s a s a n E f f e c t i v e S t r a t e g y f o r S t u d e n t s t o L e a r n H o w t o B e c o m e P r o f i c i e n t D i a g n o s t i c i a n s Bobcat Hydraulics Manual International Harvester 715 Combine Service Manual International Harvester 715 Combine Service Manual