SkyTrak 8042 Service Manual - Manual (Page 488)

8.73 Model 8042, 10042, 10054 Legacy Rev. 10/03
Hydraulic System
6. Remove springs (13 and 14) and spring seat (15).
7. Lift the flange section (8) off the housing section (7).
Remove the gasket (16) from between the two
sections.
Note: In most cases, the parts inside the cylinder block
(17) will not require removal.
8. Pull the shaft (6) and the piston rotating assembly
(17) out of the pump (4). DO NOT remove the
retaining ring (18) because the cylinder block spring
(19) is under high compression.
9. Remove the valve plate (20) and bearing (21).
10. If necessary, remove the control piston assembly (22)
from the yoke (23) by removing the retaining clip from
the chain link (24).
e. Pump Cleaning
Clean all pump components with a suitable cleaner such
as trichlorethylene.
f. Pump Inspection
1. Inspect internal pump components for wear,
damage, etc. If inner surfaces of the pump DO NOT
display an ultra-smooth, polished finish, or are
damaged in any way, replace the damaged part.
Often, dirty hydraulic fluid causes failure of internal
pump seals and damage to the polished surfaces
within the pump and other hydraulic system
components.
2. If a dowel pin (9) or dowel-mounting hole is
damaged, replace the dowel or housing as required.
Note: ALWAYS replace seals, o-rings, gaskets, etc.,
with new parts to help ensure proper sealing and
operation. Lubricate seals and o-rings with clean
hydraulic oil.
3. Seal kits are available. Replace all flexible seals.
g. Pump Assembly
Assembly is generally performed in the reverse order of
disassembly.
1. Rinse all parts in an approved solvent. Blow dry and
wipe the parts with a clean, lintless cloth before
beginning assembly.
2. If installing, coat the outer edge of a new shaft seal
(12) with a non-hardening sealant (Permatex
®
Aviation Form-A-Gasket No. 3 or equivalent). DO
NOT damage the shaft seal. Press the seal into the
housing until seal is flush with the housing recess.
Wipe off excess sealant.
h. Pump Installation
1. While the pump is still on the bench, install all
fittings, except the outlet hose fitting (25), orientating
them as noted during removal.
2. Secure the check valve manifold (26) onto the pump
(27) using the four lockwashers (28) and four capscrews
(29).
CAUTION:
Injury may result if the
retaining ring for the cylinder block spring is
removed without adequate protection.
MH3230
25
26
27
28
29