Description
Hynautic KS-08 - Seal Kit for K-7 Cylinder
KS-08 is a genuine Hynautic cylinder seal kit used to reseal the K-7 inboard steering cylinder. If your cylinder is weeping externally, has moisture intrusion at the rod, or is suspected to be bypassing internally, a reseal is often the first step - provided the rod and bore are in good condition.
Note: This is a legacy service part and availability can be limited. If your cylinder has corrosion, scoring, or pitting, a reseal may not hold - consider our rebuild option in the Resources section below.
Compatibility
- Fits: Hynautic K-7 cylinder
- How to confirm: Check the cylinder model stamping on the barrel or end cap. If you are unsure, contact Tech Support with photos of the cylinder and fittings.
What’s Included
- Seal and O-ring set for one K-7 cylinder (as applicable)
- Rod wiper(s) and backup rings (as applicable)
- Additional O-rings for glands/ports (as applicable)
Note: Contents can vary slightly by cylinder revision. Reuse of hard parts is expected unless damaged.
Installation Tips
- Protect the rod: Even small nicks can ruin new seals. Use soft jaws and keep tools off the polished surface.
- Cleanliness matters: Flush debris away from the gland area before disassembly to avoid scoring the bore on removal.
- Inspect before reseal: If the rod is pitted or the bore is scored, seals may fail quickly - rebuilding is recommended.
- Use compatible fluid: Lightly lubricate seals during assembly with the correct steering fluid per the system manual.
Maintenance Guidelines
- Keep the cylinder and surrounding bilge area clean and dry where possible to reduce corrosion.
- Check for play, weeping, or fluid film at the rod wiper during routine inspections.
- If steering feels inconsistent (drifting, pull, or frequent wheel correction), verify fluid level and bleed the system - then evaluate for internal bypass.
FAQs
Will KS-08 fix internal bypass?
Sometimes. If bypass is caused by worn piston seals and the rod/bore are in good condition, resealing can restore performance. If the bore is scored or corrosion is present, a rebuild is the better long-term fix.
Do I need any special tools?
Basic hand tools, soft jaws, snap-ring/retaining wire handling tools (as applicable), and clean assembly practices. Follow the service manual for your cylinder configuration.
How do I confirm my cylinder model?
Look for the stamped model on the cylinder barrel or end cap. If it is unreadable, send photos to our Tech Support Page.
Related Hynautic Cylinder Seal Kits
| Part No. | Fits Cylinder(s) | Notes |
|---|---|---|
| KS-08 | K-7 | This page |
| KS-07 | K-10 | Legacy kit |
| KS-05 | K-31 | Fixed mount cylinder |
| KS-06 | K-21 to K-29 (post-1983) | After Aug 1983 |
| KS-04 | K-21 to K-29 (pre-1983) | Before Aug 1983 |
| KS-02 | K-18, K-19, K-20 | Ball bracket style |
| KS-03 | K-2, H-100 | Legacy kit |
| KS-12 | K-2(B) | K-2 variant |
| KS-13 | K-3 (prior to 4-15-94) | Older K-3 |
| KS-14 | K-51 | Large inboard |
| KS-19 | K-6 | Legacy kit |
Downloads and Resources
| Description | Link |
|---|---|
| Hynautic Steering System Manual - general reference | LINK [PDF] |
| Hydraulic Cylinder Installation and Reference Guide | 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.
Warranty Information
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