Service Manual

TEST NO. 1: Pump Flow and Relief Pressure
1. Make sure hydraulic oil is at normal operating temper-
ature before performing tests.
2. Raise and support dump box if installed, then engage
parking brake and stop the engine.
3. Install tester in series between pump outlet (pressure
hose) and dump valve or steering valve on units without
dump cylinders. Make sure tester flow control valve is
open.
CAUTION
The engine must be running to perform hy-
draulic tests. To guard against possible per-
sonal injury, engage parking brake and keep
clothing, hands, feet, face and other parts of
the body away from fan or other moving parts.
4. Start engine and operate at full speed (pump seed of
2,250 RPM). While watching pressure gauges, slowly
close flow control valve until the following pressure is ob-
tained:
1,500 PSI on units
with dump cylinders
800 PSI on units without dump cylinders.
Read gauges and observe that flow is the following:
Nominal Pump Flow 3.5 GPM at 1,500 PSI
(Units with Dump Cylinders) (13.2 Liter/min. at 10,342 kPa)
Nominal Pump Flow 3.7 GPM at 800 PSI
(Units without Dump Cylinders) (14.0 Liter/min. at 5,516 kPa)
If pressure is too low or
flow is less than the following:
3.0 GPM (11.4 Liter/min.)on units with dump
cylinders
3.1 GPM (11.7 Liter/min.) on units without
dump cylinders.
check for:
– Slipping pump drive belt.
– Worn or stuck relief valve.
– Restriction in pump intake line.
– Worn or damaged pump.
1
2
Figure 10
1. Pump outlet 2. Hydraulic pump
Relief Pressure Test
5. Start engine and operate at full speed (pump seed of
2.250 RPM).
Leave tester flow control valve open.
Watch pressure gauges.
On units with dump cylinders, actuate and hold
hydraulic dump control lever so oil flow goes over relief.
On units without dump cylinders, close flow
control valve so oil flow goes over relief.
Pump Relief Pressure 2,500 PSI (17,238 kPa)
(Units with Dump Cylinders)
Pump Relief Pressure 1,000 PSI (6,895 kPa)
(Units without Dump Cylinders)
If unable to get specified pressure, check for:
– Slipping pump drive belt.
– Worn or stuck relief valve.
– Internal leakage of dump cylinder(s).
Hydraulic
System)
Workman 3000/4000 Series Page 9 – 13
Rev. D
Hydraulic System