Bulletin 2751-001-M1/USA
Service Manual
HGA Hydraguide™
Hydraulics
Parker Hannifin Corporation
Hydraulic Pump/Motor Division
Greeneville, Tennessee
14
Service Procedure
SEAL REPLACEMENT INSTRUCTIONS
For numerous installation you may want to purchase the J26910 tool kit available from KENT MOORE TOOL
DIVISION, 29784 Little Mack, Roseville, Michigan 48066 - Phone (800) 345-2233.
Caution: Follow the instructions and do not disassemble the Hydraguide unit upper cover (7) to replace the shaft
seal (5).
1. Remove the steering wheel nut (1), steering wheel
and steering wheel column, if applicable. Refer to
page 18 for instructions on removal of steering
wheel column.
2. Remove the dirt seal (2) over the end of the
Hydraguide unit upper cover, if applicable. Discard
this part.
3. Remove the retaining ring (3), do not discard, this
part must be reinstalled during assembly procedure.
4. Remove the seal package parts (4) (5) from the
Hydraguide unit by one of the following methods:
a) If the Hydraguide unit has not been removed
from the vehicle, rotate the Hydraguide unit
input shaft either clockwise or counter clockwise
to pressurize the system and force the seal
package out. Discard these parts.
b) If the Hydraguide unit has been removed from
the vehicle plug three of the four ports in the
Hydraguide unit and pressurize the other port
with air pressure to force the seal package out.
Discard these parts.
5. Note: Clean the Hydraguide unit input shaft (16)
and upper cover (7) seal bore to remove particles
of dirt, felt, lint, etc. with a clean, lint-free rag.
Caution: excessive particles of felt or lint can cause
the new seal package to leak.
6. Cover the end of the Hydraguide unit input shaft
with cellophane tape to protect the new seal (5)
when it is assembled over the sharp edges of the
input shaft.
7. Lubricate the new seal using hydraulic oil and
install the new seal (5) with lip side first, onto the
Hydraguide unit input shaft.
8. Remove the cellophane tape from the Hydraguide
unit input shaft.
9. Assemble the new washer (4), with small end first,
onto the Hydraguide unit input shaft and push the
new washer and the new seal (5), previously
installed, down into the Hydraguide unit upper
cover. (A short piece of metal tubing 15/16 mini-
mum I.D. x 1-3/16 maximum O.D. or a 7/8 deep
well socket may be used to push these parts into
place.)
10. Assemble the previously used retaining ring (3)
onto the Hydraguide unit input shaft and down into
the Hydraguide unit upper cover groove. Be sure
the rounded edge of the retaining ring (3) is faced
inward.
11. Assemble the new seal (2) onto the Hydraguide
unit input shaft and down into the Hydraguide unit
upper cover (7) counter bore.
12. Assemble the steering column, if applicable.
13. Assemble the steering wheel and wheel nut,
torque the wheel nut to 35 ft. lbs.
SERVICING OF HGA UNIT
Refer to exploded view, Figure HGA-6 for parts identification.
The spool (22) and the housing (25), the commutator (34), and commutator ring (33), as well as the rotor (31B)
and the stator (31A) are not separately replaceable because they are selectively fitted at the factory. If the spool
or housing need replacement, the complete housing assembly must be replaced. If the commutator or the
commutator ring need replacement, both must be replaced as a matched set. If the rotor or stator need replace-
ment, the complete rotor set (31) must be replaced. The pin in the end cover is not separately replaceable. If the
pin or end cover need replacement, the end cover and pin assembly (38) must be replaced.
