Hynautic K-27 Fixed Mount Balanced Steering Cylinder - 1.5" Bore x 10" Stroke (2 Ball Joint Ends)

Hynautic K-27 Fixed-Mount Balanced Steering Cylinder - 1.5" Bore x 10" Stroke (2 Ball Joint Ends)

The Hynautic K27 is a double rod end, tie-rod constructed hydraulic steering cylinder designed for rigid mounting on an immovable surface. The K-27 configuration uses two ball joint rod ends to help accommodate alignment changes through the steering arc.

IMPORTANT NOTE: Image is of a K-22, not the double ball joint K-27.

Special Note: The K27 is available again as its own brand, manufactured in the USA, the cylinder will differ in some visual aspects but is the same part.

Features

• Balanced, double rod end cylinder for consistent steering response
• Rigid fixed-mount design for inboard steering installations
• Two ball joint rod ends to help compensate for alignment changes
• Four total hydraulic ports - two 1/4" NPTF ports per end (pressure and relief)
• Integrated bleed screws to simplify purging (mount with bleeds facing up)

Specifications

Dimensions and Clearance

Compatibility and Service Parts

• Ball joints: The K-27 uses two ball joint rod ends. If you are converting a K-22-style setup to two ball joints, the HP6039 ball joint is commonly used.
• Cylinder seal kits:
  • Pre-1983 K-21 through K-29 cylinders: KS-04
  • Post-1983 (after Aug 1983) K-21 through K-29 cylinders: KS-06
  If you are unsure which kit you need, send photos of the cylinder end cap and rod end through Tech Support.

Installation Tips

• Mount the cylinder so the bleed screws face up to make purging easier.
• Confirm the steering arm geometry allows full travel without binding at either lock.
• Use marine-rated hydraulic fluid specified for the system and follow factory fill and bleed procedures.
• After installation, cycle steering lock-to-lock and inspect all fittings for seepage under load.

Maintenance Guidelines

• Inspect rod ends and mounting hardware for play, corrosion, and cracking each season.
• Keep the cylinder rod clean and free of nicks to protect internal seals.
• Address any external leakage promptly - small leaks can introduce air and cause spongy steering.
• If steering feels uneven or bypassing is suspected, reseal or rebuild the cylinder to restore performance.

FAQs

How do I know if I need KS-04 or KS-06?
KS-04 is for K-21 through K-29 cylinders built prior to 1983. KS-06 is for K-21 through K-29 cylinders built after August 1983. If in doubt, contact Tech Support with photos.

Can I replace just the ball joints?
Yes. If the cylinder body is in good condition, worn rod-end ball joints can often be serviced without replacing the entire cylinder.

What if I am unsure this is the correct cylinder?
Use the Stock Inquiry form and include your current cylinder model, photos of the end caps/ports, and your boat details so we can help confirm fitment.

Downloads and Resources

• Hynautic K-22 / K-27 / K-28 / K-29 Brass Cylinder Fact Sheet (PDF)
• Hynautic Steering Cylinder Bleeding Instructions (PDF)
• Hynautic Cylinder Rebuild Service - Bronze (Send us your cylinder)

Questions?

• Tech Support: Tech Support Page
• Check Stock: Stock Inquiry Page
• Shipping Quote: Request Quote Page

Seatech Marine Products, Inc. is an authorized dealer, service center and installer for Hynautic.