MJM Yachts 34z Express - Manual (Page 17)

CHAPTER 4 STEERING CONTROL SYSTEM
- 17 - 34z
As indicated in applicable diagram in step 5 below.
For unbalanced cylinders the oil level in the helm must be set with the cylinder rod
fully retracted. Failing to observe this caution will result in an oil spill at the helm.
Turning the wheel port (left) will retract the cylinder rod.
Filling & Purging the SeaStar System
This procedure requires two people. One person may not be able to remove all the air from the
system which will result in spongy, unresponsive steering.
During the entire filling procedure, oil must be visible in the filler tube. Do not allow the oil level to
disappear into the helm pump, as this may introduce air into the system and increase your filling time
Hydraulic Fluid/Oil Requirements
2 bottles (2 quarts or liters) for single station and single cylinder systems.
1 additional bottle for each additional helm, cylinder, or auto pilot.
These instructions will result in hydraulic oil flushed in and out of the system. Oil can be reused
if filtered through a fine mesh screen such as used for gasoline. If unable to filter oil, an additional bottle
of oil is required.
"Bleeder" may refer to cylinders fitted with bleed tee fittings or bleed screws. If fitted with bleed
tee fitting, open bleeder by unscrewing bleed nipple nut two turns.
If cylinder is fitted with bleed screws, open bleeder by
removing bleed screw completely. Loosening bleed screw
only, will not cause sufficient oil flow to purge system.
Recommended oils for your steering system are:
• SeaStar Hydraulic Fluid, part# HA5430
• Texaco HO15
• Shell Aero 4
• Esso Univis N15
• Chevron Aviation Fluid A
• Mobil
Aero HFA
• Fluids meeting Mil H5606C specifications.
• Automatic transmission fluid Dexron II may be used in an
emergency.
• Never use brake fluid. Any non-approved fluid may cause irreparable damage, loss of steering, and
cancellation of warranty.
In cases of extreme emergency any non-toxic, non-flammable fluid may provide temporary
steering.