Page 119
Speed Level Seres - Servce & Parts Manual
January 2019
Secton 8 - Troubleshootng - 3084RT Models
Adjustments - 3084RT
This machine uses a variable displacement, pressure compensated, piston type hydraulic pump.
Proper adjustment is critical for normal operation of the machine.
All of the following steps must be performed in sequence to achieve proper adjustment and machine
performance.
Refer to “Adjustable Valves Location - 3084RT” on page 118.
See Section 11 - Schematics for correct pressure settings.
Main Relief and Standby Pressure Adjustments
Start engine and operate the unit for 15 minutes or until the hydraulic fluid is warm.
Insert a 0 – 5000 PSI (0-345 bar) gauge onto the manifold pressure gauge port.
Remove the acorn nut from the Main Relief adjustment screw. Loosen the jam nut and turn the
screw counterclockwise 3 turns. Tighten the jam nut and install the acorn nut.
Remove the acorn nut from the Standby adjustment screw and loosen the jam nut. Turn the
screw clockwise 3 turns or until the needle on the gauge stops climbing. At this point the gauge
is reading full main relief pressure.
Access the Main Relief screw again and adjust it until the gauge settles at 2800 PSI (193.5 bar).
Tighten the jam nut and install the acorn nut.
Check the gauge reading again to ensure the setting did not change.
Turn the Standby adjustment screw counterclockwise until the gauge reads 550 PSI (38 bar).
Tighten the jamb nut and install the acorn nut.
Check the gauge reading again to ensure the setting did not change.
Pump Displacement Adjustment
This adjustment is set at the factory and should not be altered. The displacement adjustment controls
the maximum amount of fluid flow that the pump will produce per revolution. Excessive flow will result
in severe engine loading and stalling. Reduced flow will result in slower functions with no engine
loading. If you suspect that the setting is incorrect, please call MEC Product Support at (800) 387-
4575 for assistance.
Lift Relief (RV1)
The Lift Relief valve is located on the left-side, center of the valve manifold. It will be necessary to
remove the cap from the relief valve if adjustment is necessary. REMOVING THE CAP WHILE THE
ENGINE IS RUNNING WILL RESULT IN FLUID LEAKAGE.
To check Lift Relief valve setting, park the machine on a firm level surface free from overhead
obstructions.
Extend the platform to full height with
no load on platform
.
Hold the switch for 10 seconds to get an accurate reading on the pressure gauge.
If pressure is LOW, adjust lift relief valve ¼ turn clockwise and recheck.
If pressure is HIGH, adjust lift relief valve ¼ turn counterclockwise and recheck.
Repeat until correct.
Steering Relief (RV2)
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