Service Manual

Groundsmaster 4300--D Hydraulic SystemPage 4 -- 41
CAUTION
Before opening hydraulic system, operate all hy-
draulic controls to relieve system pressure and
avoid injury from pressurized hydraulic oil. See
Relieving Hydraulic System Pressure in the Gen-
eral Information section of this chapter.
5. Attachaheavychaintotherearofthemachineframe
and an immovable object to prevent the machine from
moving during testing.
6. Chock front wheels to prevent wheel rotation. Make
sure parking brake is applied.
7. Jack up and support the rear wheels off the ground
to allow flow through the rear wheel motors.
8. Thoroughly clean junction of hydraulic hose and
right side elbow fitting on bottom of traction pump (Fig.
42). Disconnect hose from right side pump fitting.
IMPORTANT: Make sure that the oil flow indicator
arrow on the flow meter is showing that the oil will
flow from the pump, through the tester and into the
disconnected hydraulic hose.
9. Install tester w ith pressure gauges and flow meter in
series with the traction pump and the disconnected
hose. Make sure the tester flow control valve is fully
open.
10.Start engine and move throttle to full speed (3200
RPM).
CAUTION
Use extreme caution when performing test. The
front tires on the ground will be trying to move
themachineforward.
11.Slowly push traction pedal in forward direction until
1000 PSI (70 bar) is displayed on the tester pressure
gauge. Make sure that front wheels are not rotating.
12.Total front wheel motor internal leakage will be
shown on flow meter in GPM (LPM). Leakage for the
front wheel motors should be less than 1.5 GPM (5.7
LPM).
13.Release traction pedal, shut engine off, rotate both
front wheels one--third turn and retest. Testing of wheel
motor leakage in three (3) different wheel positions will
providethemostaccuratetestresults.Ifleakagespecifi-
cations are not met, individual front wheel motors need
to be tested.
14.To test individual front wheel motors:
A. Remove front wheel from wheel motor that is not
being tested. Remove wheel shield to allow access
to hydraulic tubes and fittings on wheel motor. Re-
move fasteners that secure front hydraulic tube r--
clamps to frame.
B. On the front wheel motor that is not being tested,
thoroughlycleanjunctionofbothhydraulictubesand
wheel motor fittings. Disconnect both hydraulic lines
from wheel motor that is not being tested. Cap dis-
connected hydraulic lines and wheel motor fittings.
C. Use the procedure described in steps 8 to 11
above to identify individual front wheel motor leak-
age. Individual motor internal leakage will be shown
on flow meter in GPM (LPM). Flow should be less
than 1.5 GPM (5.7 LPM) for the tested wheel motor.
D. If other front wheel motor requires testing, com-
plete steps A, B and C for remaining wheel motor.
15.After testing is completed, stop engine and then re-
lieve hydraulic system pressure (see Relieving Hydrau-
lic System Pressure in the General Information section
of this chapter). Disconnect tester from hydraulic fitting
and hose. Connect hose to pump elbow fitting. Remove
caps from hydraulic tubes and reconnect tubes to wheel
motor.Securehydraulictubestomachinewithr--clamps
and removed fasteners. Install wheel shield and
wheel(s) (see Wheels in the Service and Repairs sec-
tion of Chapter 6 -- Chassis).
1. Traction pump
2. RH elbow fitting
3. Hyd hose (forward)
4. LH elbow fitting
5. Hyd hose (reverse)
Figure 42
FRONT
RIGHT
2
3
1
4
5
Hydraulic
System