Toro 30874 Lawn Mower User Manual


 
Groundsmaster 4500--D/4700--D Hydraulic SystemPage 4 -- 121
Disassembly (Fig. 102)
1. Remove oil from steering cylinder into a drain pan by
slowly pumping the cylinder shaft. Plug both ports and
clean the outside of the cylinder.
IMPORTANT: Prevent damage when clamping the
cylinder in a vise; clamp on the clevis only. Do not
close vise enough to distort the barrel.
2. Mount steering cylinder securely in a vise by clamp-
ing on the clevis end of the barrel. Use of a vise with soft
jaws is recommended.
3. Loosen head from barrel:
A. Use a spanner wrench to rotate head clockwise
until the edge of the retaining ring appears in the bar-
rel opening.
B. Insert a screwdriver under the beveled edge of
the retaining ring to start the retaining ring through
the opening.
C. Rotate the head counter--clockwise to remove re-
taining r ing from barrel and head.
4. Extract shaft with head and piston by carefully twist-
ing and pulling on the shaft.
IMPORTANT: Do not clamp vise jaws against the
shaft surface. Protect shaft surface before mount-
ing in a vise.
5. Mount shaft securely in avise by clamping on the cle-
vis of the shaft. Remove lock nut and piston from the
shaft. Slide head off the shaft.
6. Remove and discard all seals and O--rings from the
piston and the head.
7. Wash parts in clean solvent. Dry parts with com-
pressed air. Do not wipe parts dry with paper towels or
cloth. Lint in a hydraulic system will cause damage.
8. Carefully inspect internal surface of barrel for dam-
age (deep scratches, out--of--round, etc.). Replace en-
tire cylinder if barrel is damaged. Inspect piston rod and
piston for evidence of excessive scoring, pitting or wear.
Replace any damaged parts.
Assembly (Fig. 102)
1. Make sure all cylinder components are clean before
assembly.
2. Coat new seal kit components with clean hydraulic
oil.
A. Install new seals and O--rings to the piston.
B. Install new seals, O--ring and back--up seal to the
head.
IMPORTANT: Do not clamp vise jaws against the
shaft surface. Protect shaft surface before mount-
inginavise.
3. Mountshaft securely in avise by clamping on the cle-
vis of the shaft.
A. Coat shaft with clean hydraulic oil.
B. Carefully slide head and piston onto the shaft.
Secure piston to shaft with lock nut.
C. Torque lock nut from 30 to 36 ft--lb (41 to 48
N--m).
4. Lubricate head and piston with hydraulic oil. Careful-
ly slide shaft assembly into cylinder barrel.
IMPORTANT: Prevent damage when clamping the
cylinder ’s barrel into a vise; clamp on the clevis
only. Do not close vise enough to distort the barrel.
5. Mount steering cylinder in a vise with soft jaws. Se-
cure head in barrel:
A. Align retaining ring hole in the head with the ac-
cess slot in the barrel.
B. Insert the retaining ring hook into the hole and ro-
tate head clockwise until the r etaining ring is com-
pletely pulled into the barrel and the ring ends are
covered.
C. Apply silicone sealer to barrel access slot.
Hydraulic
System