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Hynautic BS04 Hydraulic Engine Control Reservoir

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SKU:
BS04
Condition:
New
  • Hynautic R-04 Hydraulic Engine Control Reservoir
  • Hynautic BS04 Hydraulic Engine Control Reservoir
$829.00
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Description

BS-04 Hydraulic Engine Control Reservoir - Replaces R-04

The BS04 hydraulic engine control reservoir replaces the Hynautic R04 control reservoir in hydraulic engine control systems.

This new replacement reservoir maintains extra hydraulic fluid and a constant pressure head for the control system. It is used in Hynautic engine control applications where fluid flow to and from the reservoir is regulated below the tank by the charging valve, helping the system stay pressurized as temperatures and fluid volume change.

Replaces Hynautic R-04 80 PSI pressure head Pressure tested 1 year warranty
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Technical Specifications

The BS-04 follows the function of the original R-04 reservoir by maintaining extra hydraulic fluid and a constant pressure head for the engine control system. In service, fluid flow to and from the reservoir is regulated below the reservoir by the charging valve, helping prevent pressure instability as the fluid warms and cools.

Pressure Head
80 PSI
System Type
Engine controls
Validation
Pressure tested
Warranty
1 year
System function Maintains extra hydraulic fluid and a constant pressure head so the Hynautic control system stays properly pressurized during operation.
Pressure control Fluid flow to and from the reservoir is regulated below the reservoir by the charging valve to help control pressure changes caused by thermal expansion.
Application fit Used in Hynautic hydraulic engine control systems on boats that originally used the R-04 style control reservoir.
Fluid requirement Use HA5455 Hynautic shift and throttle control fluid only for this control system application.
Service guidance During filling and bleeding, the reservoir level is typically maintained around one-half to two-thirds full with reservoir pressure generally verified in the 80 to 85 PSI range.
Build note Each new BS-04 reservoir is pressure tested before shipment to help verify it meets factory specifications.

Product Specifications

Part Number BS-04
Replaces Hynautic R-04 hydraulic engine control reservoir
Product Type Hydraulic engine control reservoir
Application Hynautic hydraulic engine control systems
Pressure Head 80 PSI nominal system pressure
Flow Regulation Regulated below the reservoir by the charging valve
Fluid Requirement HA5455 Hynautic shift and throttle control fluid only
Testing Pressure tested prior to shipment
Manufacturer Boat Steering Solutions LLC
Warranty 1 year warranty from date of purchase
Direct R-04 Replacement Built as a new replacement reservoir for original Hynautic R-04 control reservoir installations.
80 PSI Pressure Head Maintains the constant system pressure head needed for proper hydraulic engine control operation.
Service-Friendly Support Backed by current fluid, charging valve, rebuild, and engine control support options for legacy Hynautic systems.
Applications and Installation Notes

The BS-04 is intended for Hynautic hydraulic engine control systems where the original reservoir was an R-04. These systems are used to relay synchronized shift and throttle commands through hydraulic senders and slave units on a wide range of marine vessels, including pleasure craft, workboats, and commercial fishing boats.

When servicing the system, use HA5455 fluid only and follow standard Hynautic filling and bleeding procedures. The reservoir should normally be maintained about one-half to two-thirds full, and reservoir pressure is generally verified in the 80 to 85 PSI range during service. If the existing charging valve or other engine control components are worn, inspect those items at the same time rather than treating the reservoir as the only likely failure point.

Downloads and Resources
Hynautic Engine Control Manual
Download PDF
Hynautic Engine Control Filling and Bleeding Instructions
Download PDF
R-13 and R-04 Reservoir Rebuild Service
View Service
Hynautic Engine Control Parts
View Parts
Related Products and Spare Parts
HA5455
HA5455
Hynautic hydraulic fluid for engine control systems.
MCV-04
MCV-04
Hydraulic engine control charging valve used with compatible Hynautic reservoir systems.
MCV-08
MCV-08
Charge valve update fitting kit for compatible reservoir service and update work.
ECS-05
ECS-05
Seal kit for compatible 04-series Hynautic engine control sender heads.
R-R1304
R-R1304-Reservoir
Reservoir rebuild service for original R-04 and R-13 units if your existing part is rebuildable.

Frequently Asked Questions

Does the BS-04 replace the original Hynautic R-04 reservoir?
Yes. The BS-04 is sold as the replacement for the Hynautic R-04 hydraulic engine control reservoir.
What does this reservoir do in the control system?
It maintains extra hydraulic fluid and a constant pressure head for the engine control system so the controls remain properly pressurized during operation.
What fluid should be used in this reservoir?
Use HA5455 Hynautic shift and throttle control fluid only. Do not substitute standard steering fluid or stop-leak type antifreeze in the engine control system.
What pressure and fluid level should I look for during service?
During filling and bleeding, the reservoir is typically maintained about one-half to two-thirds full, with reservoir pressure generally verified in the 80 to 85 PSI range.
Can an original R-04 be rebuilt instead of replaced?
Yes - if the original unit is still in rebuildable condition, reservoir rebuild service is available for R-04 and R-13 reservoirs.

Questions? We can help.

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Authorized Dealer and Service Center Seatech Marine Products, Inc. is an authorized dealer, service center and installer for Hynautic.
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Warranty Information

Seatech Marine Products is an authorized dealer, installer and service center for Hynautic. They offer a 1 year limited warranty on all it's products.
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