Service Manual

Topdresser 1800 & 2500 Hydraulic SystemPage 3 – 23
Procedure for System Relief Valve (R1) Pressure
Test:
1. Make sure hydraulic oil is at normal operating tem-
perature by operating the machine for approximately 10
minutes.
2. Park machine on a level surface. Make sure tow ve-
hicle engine is off and that the parking brake is applied.
3. Read and follow Precautions for Hydraulic Testing.
NOTE: If machine is equipped with optional brake kit,
system relief pressure can be measured with a pressure
gauge installed in manifold port (P1). While towing the
machine with the brakes applied (minimum of 3 MPH),
system relief pressure will be displayed on the pressure
gauge (see step 7 below).
IMPORTANT: Make sure to thoroughly clean around
all hydraulic connections that will be disassembled.
4. Disconnect hydraulic hose from 45
o
hydraulic fitting
on the brush motor to allow hydraulic tester (flow meter)
installation (Fig. 17).
5. Install hydraulic tester (flow meter) between discon-
nected hose and fitting. Make sure that tester flow arrow
points from the hose and into the fitting. Fully close the
flow control valve on the tester.
6. Make sure hydraulic tank is full.
7. Start engine on tow vehicle and move the Topdress-
er control handle switch to the ON position. Tow the Top-
dresser at a minimum of 3 MPH while monitoring the
pressure gauge on the hydraulic tester.
8. Once system pressure builds to relief setting, the
pressure gauge will display system relief pressure:
For machines with serial number below
240000000, system relief pressure should be
approximately 1500 PSI (103 bar).
For machines with serial number above
240000000, system relief pressure should be
approximately 1325 PSI (91 bar).
9. Stop tow vehicle, shut off engine and record test re-
sults.
10.If relief pressure specification is not met, inspect, re-
pair or adjust charge relief valve (R1) in hydraulic control
manifold (Figs. 18 and 19). Also, consider air in the hy-
draulic system, a leaking hydraulic manifold check valve
(CV1) or worn wheel motors.
11.When testing is complete, remove hydraulic tester.
Connect hydraulic hose to fitting on brush motor. Make
sure hydraulic tank is full.
1. Brush motor
2. Hydraulic hose
3. 45
o
hydraulic fitting
Figure 17
3
1
2
1. Hydraulic manifold 2. Charge relief valve R2
Figure 18
1
HYDRAULIC MANIFOLD FROM MACHINE
WITH SERIAL NUMBER BELOW 240000000
2
FRONT
1. Hydraulic manifold 2. Charge relief valve R2
Figure 19
1
2
HYDRAULIC MANIFOLD FROM MACHINE
WITH SERIAL NUMBER ABOVE 240000000
FRONT
Hydraulic
System