Toro Groundsmaster 5900 Series Service Manual page 135

Steering Relief Operation
Groundsmaster ® 5900 & 5910
16227SL Rev B
When the steering cylinders reach the end of their stroke or if a rear wheel should
encounter an obstruction (e.g. a curb) while steering, the pressure in the steering
circuit will rise. Relief valve (RV1) in the steering/deck lift manifold senses this
pressure increase. When steering circuit pressure builds to approximately 145
bar (2100 PSI), relief valve (RV1) opens and allows hydraulic flow to return to
the hydraulic reservoir. This action causes the spool of pressure compensator
valve (LC) to shift and send oil away from the steering circuit and to the deck lift
and traction charge circuits. Relief valve (RV1) controls the action of pressure
compensator valve (LC) and allows the valve to divert only enough oil flow to the
steering circuit to maintain relief pressure.
Page 5–35 Hydraulic System: Hydraulic Flow Diagrams