Service Manual

Multi Pro 5800 Hydraulic SystemPage 5 − 27
Traction Circuit − Charge Pressure Test
The traction circuit charge pressure test should be per-
formed to make sure that the traction charge circuit is
functioning correctly.
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately ten
(10) minutes. Make sure the hydraulic tank is full.
2. Park machine on a level surface, stop engine, en-
gage parking brake and remove key from the ignition
switch. After turning engine off, operate all hydraulic
controls to relieve hydraulic system pressure.
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. Thoroughly clean test port on tee fitting at charge cir-
cuit oil filter (under the hydraulic reservoir − Fig. 23).
Install 1000 PSI (70 bar) pressure gauge to test port fit-
ting.
4. After installing pressure gauge, start engine and run
at low idle speed. Check for hydraulic leakage and cor-
rect before proceeding with test.
5. Operate the engine at high idle engine speed (Diesel
Engine: 3050 to 3150 RPM, Gasoline Engine: 3200
RPM) with no load on the traction circuit (traction pedal
in the neutral position).
GAUGE READING: 250 to 300 PSI (17 to 21 bar)
6. Stop engine and record test results.
7. If there is no pressure or pressure is low, check for
restriction in pump suction line. Also, inspect charge re-
lief valve located in charge pump adapter on piston
pump (see Piston (Traction) Pump Service in the Ser-
vice and Repairs section of this chapter). If necessary,
check for damage or worn parts in internal charge pump.
Figure 23
1. Charge circuit oil filter 2. Test port
1
2
8. With the pressure gauge still connected to the test fit-
ting on oil filter, take a pressure reading while applying
load to the traction circuit in both forward and reverse.
A. Attach a heavy chain to the rear of the machine
frame and an immovable object to prevent the ma-
chine from moving during testing.
B. Chock the wheels to prevent wheel rotation dur-
ing testing.
C. Start the engine and put throttle at high idle en-
gine speed (Diesel Engine: 3050 to 3150 RPM,
Gasoline Engine: 3200 RPM).
D. Engage the brake and push the traction pedal for-
ward while monitoring the pressure gauge. Repeat
for reverse direction. Record highest pressure read-
ing obtained in each direction.
E. Stop engine and record test results.
9. If charge pressure drops more than 15% when under
traction load, the piston (traction) pump and/or rear
wheel motor(s) should be suspected of wear and ineffi-
ciency. The charge pump (integrated into the traction
(piston) pump may be worm or damaged, or the piston
pump and/or wheel motor(s) are worn or damaged. In
each example, the charge pump is not able to keep up
with internal leakage in traction circuit components.
10.After testing is completed, disconnect pressure
gauge from piston pump and reinstall cap over test port.