Hynautic K-29 Fixed-Mount Balanced Steering Cylinder - 1.5" Bore x 12" Stroke

Hynautic K-29 Fixed-Mount Balanced Steering Cylinder - 1.5" Bore x 12" Stroke (1 Ball Joint End)

The Hynautic K29 is a double rod end, tie-rod constructed hydraulic steering cylinder designed for rigid mounting on an immovable surface. The K-29 configuration uses one ball joint rod end to help accommodate alignment changes through the steering arc while maintaining a fixed-mount footprint.

IMPORTANT NOTE: Image is of a K-22, not the K-29.

Special Note: The K29 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
• One ball joint rod end for alignment compensation (Hynautic #670030 equivalent)
• Four total hydraulic ports - 1/4-18 NPTF (2 per end: pressure and relief)
• Integrated bleed screws - mount with bleeds facing up to simplify purging
• Tie-rod construction and brass body components for durability

Specifications

Dimensions and Clearance

Compatibility and Service Parts

• Ball joint rod end (1 required): HP6039 Hynautic Ball Joint (K-22 / K-27 / K-28 / K-29)
• Cylinder seal kits:
  • Pre-1983 (prior to Aug 1983): KS-04 Seal Kit (K-21 thru K-29)
  • Post-1983 (after Aug 1983): KS-06 Seal Kit (K-21 thru K-29)
• Hydraulic steering fluid (recommended): HA5430H Hydraulic Steering Fluid - 1 Quart
• Rubber boot: Hynautic #170001 (not available on K-29)

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.
• Verify clearance for the full installed envelope before drilling the mount surface.
• After installation, cycle steering lock-to-lock and inspect all fittings for seepage under load.

Maintenance Guidelines

• Inspect mounting hardware and the rod end 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

Is the K-29 balanced?
Yes. The K-29 is a balanced (double rod end) cylinder designed for consistent steering response.

Does the K-29 use one or two ball joints?
The K-29 uses one ball joint rod end. (K-27 and K-28 versions marked with ** use two ball joints.)

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 August 1983. KS-06 is for K-21 through K-29 cylinders built after August 1983. If in doubt, contact Tech Support with photos.

Downloads and Resources

• Hynautic K-22 / K-27 / K-28 / K-29 Brass Cylinder Fact Sheet (PDF)
• Hynautic Steering 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.