Service Manual

Topdresser 1800 & 2500Hydraulic System Page 3 – 46
2. Relieve sweeper hydraulic system pressure.
NOTE: The ports on the control manifold are marked to
identify hydraulic connections. Example: R1 is the sys-
tem relief valve port (See Hydraulic Schematic in Chap-
ter 6 – Foldout Diagrams to identify the function of the
hydraulic lines and cartridge valves at each manifold
port location).
3. Label all control manifold electrical and hydraulic
connections for assembly purposes.
4. Disconnect wire harness electrical connector from
solenoid valve on control manifold.
5. Clean control manifold and manifold hydraulic con-
nections. Disconnect hydraulic hoses from manifold fit-
tings.
6. Allow disconnected hydraulic lines to drain into a
suitable container. Put caps or plugs on disconnected
hoses and fittings to prevent contamination. Discard any
removed O–rings.
7. Support control manifold to prevent it from falling.
Remove four (4) cap screws and flat washers that se-
cure hydraulic manifold to the machine frame.
8. Remove hydraulic manifold from the machine.
9. Remove hydraulic fittings from manifold as needed.
Discard any removed O–rings.
Hydraulic Manifold Service (Figs. 40 and 41)
1. Make sure the control manifold is clean before re-
moving any cartridge valve.
2. If solenoid cartridge is being serviced, remove nut
securing solenoid to the cartridge valve. Carefully slide
solenoid off the valve.
CAUTION
Operate all sweeper hydraulic controls to relieve
system pressure and to avoid injury from pres-
surized hydraulic oil. See Relieving Hydraulic
System Pressure in the General Information sec-
tion of this chapter.
IMPORTANT: Use care when handling the cartridge
valve. Slight bending or distortion of the stem tube
can cause binding and malfunction.
3. Remove cartridge valve with a deep socket wrench.
Note correct location for O–rings, sealing rings and
backup rings. Remove and discard seal kit from valve.
1. Hydraulic manifold 2. Drawbar
Figure 42
1
2
4. Visually inspect the manifold port for damage to the
sealing surfaces, damaged threads and contamination.
5. Visually inspect cartridge valve for damaged sealing
surfaces and contamination.
A. Contamination may cause valves to stick or hang
up. Contamination can become lodged in small valve
orifices or seal areas causing malfunction.
B. If valve sealing surfaces appear pitted or dam-
aged, the hydraulic system may be overheating or
there may be water in the system.
CAUTION
Use eye protection such as goggles when using
compressed air for cartridge valve cleaning.
CAUTION
Abrupt movement of internal spools can cause
stored fluid to be released suddenly.
6. Clean cartridge valve by submerging valve in clean
mineral spirits to flush out contamination. Particles as
fine as talcum powder can affect the operation of high
pressure hydraulic valves. If cartridge design allows,
use a wood or plastic probe to push the internal spool in
and out 20 to 30 times to flush out contamination. Be ex-
tremely careful not to damage cartridge. Use com-
pressed air for cleaning.
7. Reinstall the cartridge valve into control manifold:
A. Lubricate new seal kit components with clean hy-
draulic oil and install on valve. The O–rings, sealing
rings and backup rings must be arranged properly on
the cartridge valve for proper operation and sealing.