Service Manual

Topdresser 1800 & 2500 Hydraulic SystemPage 3 – 27
Rotation speed of the Topdresser brush can be mea-
sured with a rotating contact RPM indicator to see if
brush motor performance is correct. Before performing
this test, the System Flow Test should be completed to
make sure that hydraulic flow from the wheel motors is
correct.
NOTE: The brush motor rotation speed will be affected
by brush bearing condition and/or binding of the brush
assembly. Make sure that these items are checked be-
fore proceeding with this test procedure.
Procedure for Brush Motor Efficiency Test
:
1. Perform System Flow Test to make sure that wheel
motor output (flow) is correct.
IMPORTANT: Make sure to thoroughly clean around
all hydraulic connections that will be disassembled.
2. Remove conveyor motor from the hydraulic system
to allow accurate testing of the brush motor:
A. Disconnect hydraulic hose from the straight hy-
draulic fitting on the brush motor (Fig. 24). Install a
clean steel plug into disconnected hose end.
B. Disconnect hydraulic hose from the longer elbow
fitting on the conveyor motor (Fig. 25). Install a clean
steel cap onto the fitting.
C. Pull hose that was disconnected from conveyor
motor through hole in frame. Connect this hose to the
open fitting on brush motor to allow a complete hy-
draulic circuit for brush motor operation. Make sure
that hose is safely positioned away from the brush
and other rotating machine parts.
3. Start engine on tow vehicle and tow the Topdresser.
Turn the Topdresser control handle switch to the ON
position.
4. While operating the machine, monitor the vehicle
speed and the brush rotational speed using a rotating
contact RPM indicator. Brush speed is dependant on
ground speed and should be as shown in the chart to the
right (Fig. 26).
5. If system flow is correct and brush RPM is low, con-
sider that the brush motor is worn or leaking internally.
NOTE: If system flow and brush RPM are correct and
conveyor is not operating correctly, thoroughly inspect
conveyor rollers and bearings for wear or damage. If
conveyor components are found to be in good condition,
consider that the conveyor motor needs repair.
1. Brush motor
2. Hose (supply) to conveyor motor
3. Hose (return) to hydraulic manifold
Figure 24
1
2
3
1. Conveyor motor
2. Longer elbow fitting
3. Hose (return) to hydraulic manifold
Figure 25
1
2
3
Ground Speed
Brush RPM
2 MPH (3.2 KPH) 160–180 RPM
3 MPH (4.8 KPH) 245–270 RPM
4 MPH (6.4 KPH) 325–360 RPM
5 MPH (8.0 KPH) 405–450 RPM
Figure 26
Hydraulic
System