Jacobsen SLF 1880, Technical/Repair Manual

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8G-44
Figure 8G-1. In-Line Flow Tester
PRESSURE TESTS
The pressure tests are frequently inconclusive in isolat-
ing a faulty component. A flow test is recommended for
isolating a problem within a circuit. The pressure tests
are useful in determining the pressure settings of pres-
sure relief valves.
CHARGE PRESSURE TEST
1. Shut off the engine.
2. Install a 500-psi (3447 kPa) pressure gauge and
in-line tee fitting between the steering unit Auxil-
iary port and the return hose (Figure 8G-2).
3. Set the parking brake, start engine, and advance
engine speed to full throttle position.
4. Record the pressure reading on indication A) on
the Charge Circuit Test Record. The charge pres-
sure should be 54 to 66 psi (372 to 455 kPa) or
145-203 psi (1000-1400 kpa) on 2011 and later
units (Figure 8G-12).
5. Shut off the engine and remove ignition key.
Conclusion
• If charge pressure is within range, charge relief
setting is correct.
• If charge pressure is not within range the charge
relief valve may need cleaning or replacement.
Charge Relief Valve
6. Remove charge relief valve plug, spring, and
cone. Inspect for, debris and damage. Clean or
replace as necessary. If the relief valve is not
clogged or damaged:
• Charge pump may be faulty.
• Traction circuit may have excessive internal
leakage.
NOTICE
The instrument tests described in this section are
intended as a guide only and may not include every
problem encountered within a hydraulic system Con-
tact your local Jacobsen dealer for additional infor-
mation and assistance.
NOTICE
It is important that all hydraulic system components
are absolutely clean, as contamination can result in
serious damage and/or improper operation. Always
clean plugs, hydraulic lines, and hose connections
when performing diagnostic tests.
Load
Valve
IN OUT
NOTICE
The charge relief valve (Figure 8G-2) cannot be
repaired or adjusted. Replace if damaged or faulty.