ULTRAFLEX HYDRAULIC
STEERING SYSTEMS

HOW THE SYSTEM WORKS

Under normal operating conditions, a turn of the steering wheel will send the oil from the helm unit into one of the two connecting hydraulic lines.
The oil will be pumped into one of the chambers of the cylinder and either extend or retract the cylinder rod, depending on the steering wheel rotation.
The fluid going out from the other chamber of the cylinder is returned to the helm via the other hydraulic line.
There are only two basic components in all the hydraulic steering systems.
These are the helm unit and the cylinder, connected by nylon or copper tubing. The helm unit consists of both a hydraulic pump and a valve assembly.
The valve assembly prevents outgoing fluid from returning along the same line, isolates each steering station, locks the rudder and eliminates rudder "feedback" to the helm.
The cylinders are double acting and may be balanced or unbalanced, (in which case the rod extends through only one end of the cylinder).
 
SUGGESTIONS AND WARNINGS WHEN SELECTING AN HYDRAULIC STEERING SYSTEM
 The strength required to drive a boat equipped with an hydraulic steering system is inversely proportional to the number of turns of the wheel lock-to-lock. The wheel turns are determined by the ratio between the cylinder volume, pump displacement and the free movement of the rudder.
With the same type of cylinder installed on the engine, the less are the turns, the faster is the response but higher is the effort; more wheel turns, slower is the response and lower is the effort.
Other factors that can influence steering effort are:
  • Vessel speed
  • Rudder dimension, or engine power
  • Propeller selection
  • Hull type (displacement, planning, etc.)
  • Sea conditions
  • Oil viscosity

     CROSS REFERENCE
FRONT MOUNT HELM PUMPS UP20 F, UP25 F, UP28 F, UP33 F, UP39 F

FEATURES

  • Available in three different displacement sizes
  • Compact design
  • Ball bearing piston race
  • Built-in lock valve for positive rudder lock
  • Integral relief valve for over-pressure protection
  • 3/4" tapered stainless steel shaft
  • Easily accessible lock valve and shaft seal for replacement
  • Cast iron rotor for greater durability and longer life
  • Convenient front of dash fill
  • 1/4" NPT fitting for 3/8" tube
  • Complete with elbow fittings
  • X56 - 39465 S square flange or X57 - 39464 P round flange permit to install the pumps in an intermediate dashboard position.

    TECHNICAL DETAILS FRONT MOUNT PUMP
UP20FM Front Mount Helm 1.2 CU. IN. 3/4"
taper shaft		 $312.00
UP25FM Front Mount Helm 1.5 CU. IN. 3/4"
taper shaft		 $390.00
UP28FM Front Mount Helm 1.7 CU. IN. 3/4" tapered shaft      $406.00
UP33FM  Front Mount Helm 2.0 CU. IN. 3/4" tapered shaft      $416.00
UP39FM Front Mount Helm 2.4 CU. IN. 3/4" tapered shaft      $433.00
X56 Square Mount Flange $60.00
X57 Round Mount Flange $60.00

REAR MOUNT HELM PUMP


FEATURES

  • Available in 39 cc/rev (2.4 cu.in/rev) displacement size
  • Compact design
  • Ball bearing piston race
  • Built-in lock valve for positive rudder lock
  • Integral relief valve for over-pressure protection
  • 3/4" tapered stainless steel shaft
  • Easily accessible lock valve and shaft seal for replacement
  • Cast iron rotor for greater durability and longer life
  • 1/4" NPT fitting for 3/8" tube
  • Complete with elbow fittings
  • KIT F optional remote fill adapter

      TECHNICAL DETAILS REAR MOUNT PUMP

UP28RM Back Mount Helm 1.2 CU. IN. 3/4" tapered shaft $446.00
UP33RM Back Mount Helm 2.0 CU. IN. 3/4" tapered shaft      $454.00
UP39RM Back Mount Helm 2.4 CU. IN. 3/4" tapered shaft      $480.00
UP56RM Back Mount Helm 3.4 CU. IN. SS shaft 3/4" taper $1,329.00

TILT MOUNT HELM PUMPS
 

FEATURES

  • Available in three different displacement sizes
  • Compact design
  • Ball bearing piston race
  • Built-in lock valve for positive rudder lock
  • Integral relief valve for over-pressure protection
  • Stainless steel shaft
  • Easily accessible lock valve and shaft seal for replacement
  • Cast iron rotor for greater durability and longer life
  • 1/4" NPT fitting for 3/8" tube
  • Complete with elbow fittings
  • KIT F optional remote fill adapter (see page 64)
  • Tilt mechanism:
  • X52 - 39250 U - 90° mounting
    NOTE: X52 tilt mechanism can be used with the Ultraflex T81FC, T82FC, T83NRFC, T84NRFC mechanical steering helms also.

      TECHNICAL DETAILS TILT PUMP

UP20T Front Mount Helm 1.2 CU. IN. 3/4"
taper shaft  with X52 tilt		 $460.00
UP25T Front Mount Helm 1.5 CU. IN. 3/4"
taper shaft with X52 tilt		 $547.00
UP28T Front Mount Helm 1.7 CU. IN. 3/4" tapered shaft  with X52 tilt    $555.00
UP33T Front Mount Helm 2.0 CU. IN. 3/4" tapered shaft  with X52 tilt    $564.00
UP39T Front Mount Helm 2.4 CU. IN. 3/4" tapered shaft   with X52 tilt    $592.00