Purging The Air From The Hydraulic System; Suspension Adjustment - Ferris 400S Series Dealer Setup & Adjustment Instructions Manual

the machine), re-position the set collar so the neutral
return spring is less compressed.
• if the ground speed control lever stops it's return
motion before the notch (while standing at the rear
of the machine), re-position the set collar so that the
neutral return spring is more compressed.
6. Repeat the process as necessary until the ground speed
control lever aligns with the notch in the neutral lock plate.
Note: It is important to note that after every adjustment of the
neutral linkage rod, the ground speed control lever must be
pulled rearward and released to properly check the return-to-
neutral adjustment.
Purging the Air from the Hydraulic
System
Due to the effects air has on efficiency in hydraulic drive
systems, it is critical that it be purged from the system.
These purge procedures should be implemented any time a
hydraulic system has been opened to facilitate maintenance
or any additional oil has been added to the system.
The resulting symptoms of air in the hydraulic system may be:
• Noisy operation.
• Lack of power or drive after short term operation.
• High operation temperature and excessive expansion of
oil.
Before starting, make sure the transaxles/transmissions are
at the proper oil levels. If it is not, fill to the specifications
outlined in the Check / Fill Transmission Oil Level procedure.
Purging Air from the Hydraulic System:
1. Chock the front wheels to prevent the machine from
rolling. Raise the rear of the machine so that the vehicle's
rear tires do not contact the ground. Position jack stands
under the rear bumper of the machine to secure it.
2. Open the transaxle's bypass valves (see Uncrating for
the location and function of the bypass valves), start
the engine, release the parking brake, and slowly move
the zero-turn rider's ground speed control levers in both
forward and reverse directions (5 to 6 times), as air is
purged from the unit, the oil level will drop.
3. Stop the engine and engage the parking brake.
4. Close the transaxle's bypass valves, start the engine,
release the parking brake, and slowly move the zero-turn
rider's ground speed control levers in both forward and
reverse directions (5 to 6 times), as air is purged from the
unit, the oil level will drop.
5. Stop the engine. Remove the jack stands from
underneath the machine.
6. Repeat the process detailed above but with the unit's
drive wheels on the ground. The procedure should be
performed in an area free of any objects or bystanders.
It may be necessary to repeat the process detailed above
until all the air is completely purged from the system. When
the transaxles/transmissions operate at normal noise levels
14
and move smoothly forward and reverse at normal speeds,
then the transaxles/transmissions are considered purged.

Suspension Adjustment

The shock assemblies (A, Figure 26 - front shown, rear
similar) can be adjusted to vary the amount of pre-load
applied to the springs. This allows the operator to customize
the ride according to operator's weight and operating
conditions.
26
Less Pre-Load:
• Light operator weight
• Softer, more cushioned ride
• Best for relatively flat terrain
More Pre-Load:
• Heavy operator weight
• Stiffer, more rigid ride
• Better handling and greater stability on hilly terrain
To Adjust the Spring Pre-Load:
1. Park machine on a flat, level surface. Disengage the
PTO, pivot the ground speed control levers out to the
NEUTRAL position, and stop the engine.
2. To adjust the front shocks: Turn the pre-load
adjustment collar (B, Figure 26) with your hand to a
higher notch (-) to decrease the pre-load, or to a lower
notch (+) to increase the pre-load.
WARNING
Use two hands when adjusting the shock springs. This will
prevent the wrench from slipping while pressure is applied.
3. To adjust the rear shocks: Using the supplied spanner
wrench (p/n 5022853), insert the tip of the wrench into
the notch in the pre-load adjustment collar. While holding
the wrench in place with one hand, turn the pre-load
adjustment collar to a higher notch (-) to decrease the
pre-load, or to a lower notch (+) to increase the pre-load.
Make sure all four shocks are set to the same amount of
pre-load.
Note: The spanner wrench was included in the literature
packet for the machine.
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