SkyTrak 8042 Service Manual - Manual (Page 505)

Hydraulic System
8.90 Model 8042, 10042, 10054 Legacy Rev. 10/03
h. Main Control Valve Installation
1. Insert the carriage bolts (2 and 3) from the bottom
into the main valve (4).
2. Loosely install the hex flange nuts (1) onto the
carriage bolts (2 and 3).
3. Install the main control valve (4) into the vehicle,
aligning the carriage bolt heads (2 and 3) with the
slots (5) in the frame. Slide the main valve into
position, and tighten the nuts (1).
4. Prime the main control valve by filling the inlet
openings with fresh, filtered hydraulic oil from a
clean container, before attaching the hoses.
5. Use new oiled o-rings as required. Reattach and
secure all hoses, clamps, etc. to the main control
valve.
6. Check the routing of all hoses, wiring and tubing for
sharp bends or interference with any rotating
members, and install tie wraps and/or protective
conduit as required. Tighten all tube and hose
clamps.
7. Start the engine and run at approximately one-third
to one-half throttle for about one minute without
moving the vehicle or operating any hydraulic functions.
8. Inspect for leaks and check the level of the hydraulic
fluid in the reservoir. Shut the engine OFF.
Note: Check for leaks and repair as required before
continuing. Add hydraulic fluid to the reservoir as needed.
9. Wipe up any hydraulic fluid spillage in, on, near and
around the vehicle, work area and tools.
10. Install the transmission covers.
i. Main Control Valve Test
Conduct a pressure check of the hydraulic system in its
entirety. Adjust pressure(s) as required. Refer to Section
8.7, “Hydraulic System Testing.”
8.12.2 Secondary Function Manifold
The secondary function manifold (6) is a directional control
valve. Hydraulic oil from the pump flows into the secondary
function manifold where the pressure is reduced before the
oil is directed to the power steering unit or the park brake.
The secondary function manifold is a machined block with
ports for two pressure reducing valves, a pressure relief
valve, two park brake solenoid valves (one normally open
and one normally closed), a check valve and diagnostic test
nipples. The secondary function manifold is secured on the
left side of the frame with two carriage bolts and two hex
flange nuts.
MH3490
Front
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1
2
3
4
5
1
WARNING:
Avoid prolonged engine
operation in closed areas with inadequate
ventilation. Failure to properly ventilate exhaust
fumes can result in death or serious injury.
WARNING:
Hydraulic oil leaking under
pressure can penetrate the skin and cause
severe personal injury. DO NOT use your hand
or any part of your body to check for hydraulic
leaks. When checking for hydraulic leaks, wear
safety glasses and gloves to help provide
protection from spraying hydraulic oil. Use a
piece of cardboard or paper to search for
leaks.