October 2008 "2033ES / 2633ES" Service & Parts Manual - ANSI Specifications
Page 4-2
GENERAL TROUBLESHOOTING TIPS
The ES series Aerial Work Platform operates on a "Motor Control" theory in which fluid flow
volume is controlled by varying the speed of the DC electric motor. 100% of the fluid produced by
the pump goes to the selected function.
The ES series is designed for easier troubleshooting. There is a terminal strip located under the
platform for checking signals to and from upper controls. There is also an LED's located on the
Motor Control Unit located inside the lower control box, that will help in the event the DC electric
motor fails to operate (see Motor Controller Flash Codes in this section for troubleshooting with
flash codes). It is important to note that not all failures will cause a flash code on the motor
controller. Before you begin troubleshooting this model, check the battery state of charge and
inspect the battery connections for looseness or corrosion. A fully charged battery set on a
24 V DC system will have a nominal voltage of 25.6 V DC.
Before investigating a malfunction, check the following items:
♦ Check that battery connections are secure and battery is fully charged.
♦ Check that the emergency stop button is released (UP/OUT position).
♦ Check that the hydraulic fluid is at the correct level.
♦ Check that the brake release valve is open.
♦ Check that the circuit breaker is in the ON position.
Common Causes of Hydraulic System Malfunctions:
♦ Incompatible hydraulic fluids mixed, destroying the additives and causing varnish buildup,
resulting in the valves sticking.
♦ Water in the hydraulic fluid due to a damp climate.
♦ Improper hydraulic fluid used. Viscosity too high in cold climates. Viscosity too low in warm
climates.
NOTES: Contamination always causes failure in any hydraulic system. It is very important
to be careful not to introduce any contamination into your hydraulic system during
the assembly procedures. Make sure all ports and cavities of the manifold and
cylinders are properly covered while other work is performed.
Early Model vs. Current Model
Current model hydraulics are modified in the following ways;
♦ Electrical components use Deutsch style connectors.
♦ The brake release hand pump is on the main manifold.
♦ Valve CV1 is eliminated.
♦ Valve SV7 is eliminated.
♦ Valve SV8 is eliminated.
♦ Steering flow control valve PFC1 and relief valve RV3 are replaced by a single valve FRR1.
Refer to the accompanying illustrations when using the Troubleshooting Guide.
To Next Page
Loading...
