Toro Groundsmaster 4500-D Series Service Manual page 159

Procedure for Rear Traction Circuit Relief Valve (RV) Pressure Test
Groundsmaster ® 4500-D/4700-D
19245SL Rev A
Note: Adjustable relief valve (RV) in the rear traction control manifold reduces
rear axle motor pressure created in down hill, dynamic braking conditions to
prevent rear wheel lock up.
Prevent personal injury and/or damage to equipment. Read all
WARNINGS, CAUTIONS and Precautions for Hydraulic Testing at the
beginning of this section.
Note: If the rear traction circuit pressure reducing valve (PR) pressure is
excessive, operation of the rear traction relief valve (RV) may be affected. Before
adjusting rear traction relief valve (RV), make sure that pressure reducing valve
(PR) pressure is correct.
1. Make sure hydraulic oil is at normal operating temperature by operating
the machine for approximately ten (10) minutes. Make sure the hydraulic
reservoir is full.
2. Park machine on a level surface with the cutting decks lowered and off. Make
sure engine is off and the parking brake is engaged.
Note: This test uses the same pressure gauge position as used to measure
traction circuit pressure reducing valve (PR) pressure.
Note: The #6 zero leak plug on the inside of rear traction manifold is a zero
leak plug that has a tapered sealing surface on the plug head. Lightly rap
the plug head using a punch and hammer before using an allen wrench
to remove the plug: the impact will allow plug removal with less chance of
damage to the socket head of the plug.
g308369
1. Front frame
3. Locate rear traction manifold that is attached to the front frame next to the
left side front wheel
traction manifold and install diagnostic fitting (Toro part number 59-7410)
into manifold port.
4. Connect a 70 bar (1000 PSI) pressure gauge with hydraulic hose attached
to installed diagnostic fitting.
CAUTION
Figure 68
2. Rear traction manifold
(Figure 68). Remove #6 zero leak plug on inside of rear
Page 5–57 Hydraulic System: Testing