Service And Repairs 8 - Toro Groundsmaster 4100-D Service Manual

Procedure for Traction Circuit Charge Pressure Test
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine under load for
approximately ten (10) minutes. Make sure the hydrau-
lic tank is full.
2. Park machine on a level surface with the cutting deck
lowered and off. Make sure engine is off and the parking
brake is engaged. Raise and support operator seat.
CAUTION
Prevent personal injury and/or damage to equip-
ment. Read all WARNINGS, CAUTIONS and Pre-
cautions for Hydraulic Testing at the beginning
of this section.
3. Connect a 1000 PSI (70 bar) pressure gauge onto
charge pressure test port on filter manifold under opera-
tor seat (Fig. 26).
4. After installing pressure gauge, start engine and run
at idle speed. Check for hydraulic leakage at pressure
gauge location and correct before proceeding with test.
5. Move throttle so engine is running at high idle speed
(2870 RPM) with no load on the hydraulic system.
GAUGE READING TO BE 200 to 300 PSI (13.8 to
20.6 bar).
6. Stop engine and record test results.
7. If there is no pressure or pressure is low, check for
restriction in pump intake line. Also, inspect charge relief
valve located in filter manifold (see Filter Manifold Ser-
vice in the Service and Repairs section of this chapter).
A worn or damaged gear pump (P3) could also be con-
sidered (see Steering and Lift/Lower Gear Pump Flow
Test in this section).
NOTE: If gear pump (P3) is worn or damaged, charge,
steering and lift circuits will all be affected.
Groundsmaster 4100--D/4110--D
8. Next, with the pressure gauge still connected to the
charge pressure test port, take a gauge reading while
operating the machine in forward and reverse. Start the
engine and put throttle at high idle speed (2870 RPM).
Apply the brakes and push the traction pedal forward
while monitoring the pressure gauge. Repeat for re-
verse direction. Stop engine and record test results.
9. If charge pressure meets specifications at no load
conditions (step 5 above), but consistently drops more
than 15% when under traction load, the piston (traction)
pump and/or traction motor(s) should be suspected of
wear and inefficiency. When the pump or motors are
worn or damaged, the charge pump is not able to keep
up with internal leakage in the traction system compo-
nents.
10.When testing is completed, disconnect pressure
gauge from test port. Lower and secure operator's seat.
RIGHT
FRONT
1. Charge pressure port
Page 4 - - 39
1
2
Figure 26
2. Filter manifold
Hydraulic System