4. Remove end cap (Item 1) from pump housing.
IMPORTANT: The valve plate (Item 39) may stick to
the end cap. Do
not allow valve plate to fall from end
cap.
5. Remove gasket (Item 14) and alignment pins
(I
tem 15) from end cap.
IMPORTANT: Be careful not to damage valve plate
and end cap surfaces.
6. Carefully remove valve plate (Item 39) from end cap.
It may be necessary to pry valve plate off with a small
screwdriver.
7. Remove valve plate pins (Item 40) from end cap.
8. Lay pump housing on its side and remove cylinder
block assembly (Item 38) from housing.
9. Remove the slipper guide and piston assemblies from
cylinder block.
10. Use an o-ring pick or wire to remove thrust plate
(Item 37) from swashplate and housing.
11. Remove shaft seal carrier. (See Tandem Pump Shaft
Se
al Replacement.)
12. Slide drive shaft (Item 26) and bearing assembly
(Item 27) from housing.
13. Remove retaining ring (Item 28) and press shaft out
of bearing.
14. Remove hex tapping screws (Item 16) retaining
trunnion seal cover (Item 35) and trunnion cover
(Item 17) to housing. Mark position of covers for reas-
sembly.
15. The trunnion seal cover assembly includes an o-ring
(It
em 18) and lip seal (Item 34) on the control side and
an o-ring (Item 18), on the side opposite the control.
Re
move these parts from the housing. (See Trunnion
Seal Replacement).
16. Remove the trunnion spacers (Item 19), shims
(It
em 20) and roller bearings (Item 21) from housing and
swashplate. The bearing assemblies are a slip fit in the
housing.
17. Tilt and lift swashplate (Item 36) from housing.
Inspection and Replacement of Parts
18. After disassembly, thoroughly clean all parts in a
su
itable solvent. Replace all o-rings, gaskets and seals.
19. Inspect all parts for damage, nicks or unusual wear
patterns. Replace all parts having unusual or excessive
wear or discoloration.
20. If scratches, which can be felt with a pencil lead, can
be
found on bronze surface of valve plates or running
surface of cylinder blocks, polish or replace the parts.
21. Inspect needle bearings and drive coupling in center
se
ction. If replacement is necessary, remove shaft nee-
dle bearings using a suitable puller. Do not damage
valve plate surface of center section.
22. Press new needle bearing (Item 13) into end cap
u
sing a suitable press pin. When installed correctly,
bearing cage will protrude from 0.08 to 0.10 in. from
surface of end cap to serve as pilot for valve plate.
IMPORTANT: When installing the needle bearing,
the prin
ted (numbered) end of the bearing cage
must face the press pin.
23. Install a new cylinder block kit if brass slippers on
pisto
ns are scored or excessively rounded at edges.
Hydraulic System
Groundsmaster
®
455-D Page 4 - 33 Repairs
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