Service Manual

Table Of Contents
Groundsmaster 4500-- D/4700--D Hydraulic SystemPage 4 -- 45
Which Hydraulic Tests Are Necessary?
Before beginning any hydraulic test, identify if the prob-
lem is related to the traction circuit, cutting (mow) circuit,
lift/lower circuit, steering circuit or engine cooling fan cir-
cuit. Once the faulty system has been identified, perform
tests that relate to that circuit.
1. If a traction circuit problem exists, consider perform-
ing one or more of the following tests: Traction Circuit
Charge Pressure, Traction Circuit Relief Pressure,
Tr action Circuit Reducing Valve (PR) Pressure, Rear
Tr action Circuit Relief Valve (RV) Pressure, Gear Pump
Flow and/or Piston (Traction) Pump Flow Tests.
IMPORTANT: Refer to Traction Circuit Component
Failure in the General Information section of this
chapter for information regarding the i mportance of
removing contamination from the traction circuit.
2. If a cutting (mow) circuit problem exists, consider
performing one or more of the following tests: Cutting
Deck Circuit Pressure, Cutting Deck Circuit Relief Pres-
sure, Deck Motor Case Drain Leakage and/or Gear
Pump Flow Tests.
3. If a lift/lower circuit problem exists, consider perform-
ing one or more of the following tests: Lift/Lower Circuit
Relief Pressure and/or Gear Pump Flow Tests.
4. If a steering circuit problem exists, consider perform-
ing one or more of the following tests: Steering Circuit
Relief Pressure, Steering Cylinder Internal Leakage
and/or Gear Pump Flow Tests.
5. If a e ngine cooling fan circuit problem exists, consid-
er performing one or more of the following tests: Engine
Cooling Fan Circuit and/or Gear Pump Flow Tests.
Hydraulic
System