Toro Groundsmaster 4100-D Service Manual page 95

Procedure for Cutting Deck Gear Pump Flow Test
NOTE: Over a period of time, the gears and wear plates
in the gear pump can wear. A worn pump will by--pass
oil and make the pump less efficient. Eventually, enough
oil loss will occur to cause the cutting deck motors to stall
under heavy cutting conditions. Continued operation
with a worn, inefficient pump can generate excessive
heat and cause damage to the seals and other compo-
nents in the hydraulic system.
IMPORTANT: Mow circuit flow for the Groundsmas-
ter 4100/4110 is approximately 16 GPM (61 LPM).
Use 40 GPM Hydraulic Tester #AT40002 (pressure
and flow) for this test (see Special Tools in this
chapter).
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.
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. Locate PTO control manifold for gear pump section
to be tested (front or LH manifold). Thoroughly clean
junction of manifold fitting and hydraulic hose at PTO
manifold port (P1) (Fig. 43). Disconnect hydraulic hose
from port (P1) fitting.
4. Install 40 GPM Hydraulic Tester #AT40002 (pres-
sure and flow) in series with the disconnected hose and
hydraulic manifold port (P1). Use hydraulic hose kit (see
Special Tools in this chapter) to connect tester to ma-
chine. Make sure the flow control valve on the tester
is fully open.
5. After installing tester, start engine and run at idle
speed. Check for hydraulic leakage at tester location
and correct before proceeding with test.
6. Move throttle so engine is running at high idle speed
(2870 RPM). Do not engage the cutting deck.
Groundsmaster 4100--D/4110--D
IMPORTANT: Do not fully restrict oil flow through
tester. In this test, the flow tester is positioned be-
fore the relief valve. Pump damage can occur if the
oil flow is fully restricted.
7. Watch pressure gauge carefully while slowly closing
the tester flow control valve until 2000 PSI is obtained.
Verify with a phototac that the engine speed is still 2870
RPM.
NOTE: If engine speed drops below 2870 RPM, pump
flow will decrease.
8. For a gear pump in good condition, pump flow should
be approximately 16 GPM (61 LPM). Fully open tester
flow control valve and shut off engine. Record test re-
sults.
9. If measured flow is less than 14 GPM (53 LPM) or
if a pressure of 2000 PSI cannot be obtained, check for
restriction in the pump intake line. If line is not restricted,
remove gear pump and repair or replace as necessary.
10.When testing is complete, disconnect tester and
hose kit from manifold port and machine hydraulic hose.
Reconnect machine hose to the manifold.
11. Repeat test for second cutting deck gear pump sec-
tion if required.
RIGHT
FRONT
1. Center deck manifold
2. Hyd. hose to front P1
Page 4 - - 57
TO OIL COOLER
1
4
2
Figure 43
3. LH wing deck manifold
4. Hyd. hose to side P1
Hydraulic System
3