Service Manual

Groundsmaster 7200/7210 Hydraulic SystemPage 4 - 95
Disassembly (Fig. 107)
1. Plug all ports and c lean the outside of the valve thor-
oughly.
IMPORTANT: Match- mark spools to their associat-
ed bores before disassembly. Spools must be rein-
stalled to the bore from which they were removed.
2. Remove both spool caps (item 10) and slide the
spool assemblies from their bores.
3. Remove O- ring (item 12) and bushing (item 8) from
each spool assembly.
4. Remove wiper seals (item 20) and O- rings (item 12)
from the spool bore ends that are opposite the spool
caps.
NOTE: Disassemble spool assemblies only if the re-
taining r ing (item 13), spacer (item 3), spool spring (item
16) or washer (item 14) need replacing.
5. Remove seat retaining plugs (items 7 and 15), back-
up washers, O- rings and check spring (item 9) from the
valve body.
6. Remove check poppet (item 1), seats (item 5), O-
rings (item 27) and plungers (items 2 and 21) from the
valve body.
7. Remove solid plug (item 6), back- up washer and O-
ring from the opposite end of the plunger.
8. Remove detent plug (item 19) and O- ring from the
valve body. Remove disc, spring and detent plunger
from the body.
Inspection
1. Inspect spools and spool bores for wear. If wear is
excessive, replace control valve with new one.
2. Inspect springs and replace as necessary.
3. Inspect plunger and detent plunger for wear. Re-
place as necessary.
4. Inspect caps and plugs for damaged threads and in-
spect O- ring sealing surfaces. Replace as necessary.
Assembly (Fig. 107)
IMPORTANT: Do not wipe control valve parts with
dry paper towels or rags. Lint may cause damage to
the hydraulic system.
CAUTION
Use eye protection such as goggles when using
compressed air.
1. Clean all metal parts with solvent and blow dry with
compressed air.
2. Replace check poppet (item 1), O- rings and back-
up washers with new ones.
3. Install new O- rings (item 12) into the valve body.
4. If a spool was disassembled, install washer ( item
14), spool spring (item 16), spacer (item 3) and retaining
ring (item 13) to the spool.
5. Slide bushings (item 8) and new O- rings (item 12)
over the spools.
6. Lubricate spools liberally with clean hydraulic fluid
and carefully install into their proper bore.
7. Install spool caps (item 10) into valve body. Torque
caps from 20 to 25 ft- lb (27 to 33 N- m).
8. Lubricate both plungers (items 2 and 21) liberally
with clean hydraulic fluid and install into their proper
bore.
9. Install new O- rings, seats (item 5), check poppet
(item 1) and check spring (item 9) into the plunger bores.
10.Install O- rings, back- up washers and seat retaining
plugs (items 7 and 15) into their plunger bores. Torque
plugs from 30 to 35 ft- lb (41 to 47 N- m).
11. Install new O- ring, back- up washer and solid plug
(item 6) into the bore with the detent plunger. Torque
plug from 30 to 35 ft- lb (41 to 47 N- m).
12.Lubricate detent plunger (item 22), spring a nd disc
liberally with clean hydraulic fluid and install into valve
body bore.
13.Install O- ring and detent plug (item 19) into valve
body. Torque plug from 4to5ft-lb(5.4to6.8N-m).
Hydraulic
System