Description
Hynautic KS-05 - Seal Kit for K-31 Cylinder
The Hynautic KS05 is the genuine Hynautic cylinder seal kit for refreshing the K31 inboard steering cylinder. Typical contents include replacement O-rings, to reseal one cylinder. Always verify the exact cylinder model and revision before ordering.
Compatibility
- Fits: Hynautic K-31 cylinder
- Does not fit: K-1, K-2(B), K-3, K-6, K-11, K-12, K-18, K-19, K-21 through K-29, K-51, etc. See related kits below.
- How to confirm: Check the cylinder’s stamped model on the end cap or barrel. If unsure, contact Tech Support with photos.
What’s Included
- Seal and O-ring set for one K-31 cylinder
Note: Contents can vary slightly by cylinder revision. Reuse of hard parts is expected unless damaged.
Related Hynautic Cylinder Seal Kits
| Part No. | Fits Cylinder(s) | Notes |
|---|---|---|
| KS-05 | K-31 | This page |
| KS-01 | K-11, K-12 | Small inboard |
| KS-02 | K-18, K-19 | Ball bracket style |
| KS-04 | K-21 to K-29 (pre-1983) | Early cylinders |
| KS-06 | K-21 to K-29 (post 1983) | Later cylinders |
| KS-13 | K-3 (prior to 4-15-94) | Older K-3 |
| KS-14 | K-51 | Large inboard |
| KS-19 | K-6 | Limited availability |
Install Overview - Resealing a Hynautic Cylinder
This is a high-level overview to help you plan the job. Follow the Hynautic service manual for exact steps and specs.
- Prep - Clean the exterior, secure steering, and mark current hardware locations. Protect the rod from scratches.
- Disassemble - Depressurize the system. Remove retaining wire(s) and end cap per the manual. Withdraw rod and piston assembly.
- Inspect - Check the rod surface for nicks and the bore for scoring. Replace damaged hard parts before reseal.
- Reseal - Replace O-rings, backups, and wipers from KS-05. Lightly lubricate seals with compatible hydraulic fluid.
- Reassemble - Install rod assembly, seat end cap, and re-fit retaining wire(s). Verify smooth travel by hand.
- Bleed and test - Refill, bleed air, and verify full stroke without binding or leaks. Sea trial under safe conditions.
Downloads and Resources
| Description | Link |
|---|---|
| Hynautic Steering System Manual - general reference | LINK [PDF] |
| Inboard Cylinder Installation and Reference | LINK [PDF] |
| Hynautic Cylinder Rebuild Service | LINK [Service] |
Questions?
- Tech Support: Tech Support Page
- Check Stock: Stock Inquiry Page
- Request a Shipping Quote: Request Quote Page
- Learn More About Seatech: About Us Page
- No Sales Tax on purchases outside California
- Buy Now Pay Later with Affirm or PayPal
- FREE Ground Shipping to the Lower 48 States
- Seatech Marine Products, Inc. is an authorized dealer, service center and installer for Hynautic
International, USVI, Puerto Rican, Hawaiian and Alaskan Customers: We ship worldwide and via USPS. If shipping looks high, contact us for a quote.
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