Hydraulic Manifold Assembly Connector Kit – Fits MerCruiser Alpha One Gen 2 & Bravo Drives
This hydraulic manifold connector assembly is designed for MerCruiser stern drives, including MC-1, R, MR, Alpha One Gen 2, and Bravo I, II, and III models from 1983 and newer. It serves as a crucial component for the power trim hydraulic system, ensuring reliable fluid distribution.
This kit provides a direct replacement for multiple OEM and aftermarket part numbers, restoring the integrity and function of your vessel's trim and tilt hydraulics.
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Installation: Direct bolt-on replacement for a straightforward installation.
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System Connection: Features 2 hydraulic line inputs and 4 outputs.
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Construction: Made from corrosion-resistant aluminum for durability in marine environments.
Part Number Cross-Reference
Use this table to confirm equivalent part numbers across OEM and aftermarket brands.
| Brand |
Part Number |
| Mercury / MerCruiser |
8M0137703 |
| Mercury / MerCruiser |
8M0080805 |
| Mercury / MerCruiser |
98825A4 |
| Mercury / MerCruiser |
98825A12 |
| GLM |
21970 |
| Sterndrive Engineering |
9F-116-17K |
Compatible Engine Models
Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.
| Brand |
Model |
Years |
OEM Part No. |
Notes |
| MerCruiser |
MC-1 |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
R |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
MR |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
Alpha One Gen 2 |
1991 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
Bravo I |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
Bravo II |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
Bravo III |
1983 & Up |
8M0137703/8M0080805 |
|
| MerCruiser |
Bravo X |
|
8M0137703/8M0080805 |
|
| MerCruiser |
Bravo XR |
|
8M0137703/8M0080805 |
Includes XR sportmaster |
| MerCruiser |
Bravo XZ |
|
8M0137703/8M0080805 |
|
Technical Specifications
| Specification |
Value |
| Product Type |
Hydraulic Power Trim Line Manifold Connector Assembly |
| Installation |
Direct bolt-on replacement |
| Connection |
2 inputs, 4 outputs |
| Housing Material |
Aluminum |
| Housing Color |
Silver/metallic |
| Weight |
0.40 lb (0.18 kg) |
| Other Technical Attributes |
Corrosion-resistant aluminum construction |
Package Contents
- 1 x Plate
- 1 x Junction Block Body
- 2 x Gaskets (Replaces 27-98823-1)
- 2 x Lockwashers (Replaces 13-78968)
- 2 x Mounting Bolts/Screws (Replaces 10-28668)
Installation Guide
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Safety First: Disconnect the boat's battery and ensure the stern drive is in the fully down position and properly supported.
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Access the Manifold: Locate the hydraulic manifold assembly on the gimbal housing. It is typically found where the hydraulic lines enter the transom.
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Drain Fluid: Place a drain pan under the assembly to catch any residual hydraulic fluid upon disconnection.
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Disconnect Lines: Carefully disconnect the four hydraulic lines from the manifold block. Label them to ensure correct reassembly.
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Remove Old Assembly: Unbolt the two mounting screws holding the manifold body and plate to the housing. Remove the entire old assembly, including gaskets.
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Clean Surface: Thoroughly clean the mounting surface on the gimbal housing to remove old gasket material and corrosion.
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Install New Assembly: Place one new gasket onto the new manifold body, position it against the housing, place the second gasket on the plate, and secure the new assembly using the new mounting bolts and lockwashers.
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Reconnect Lines: Reconnect the four hydraulic lines to their correct ports on the new junction block. Ensure fittings are snug but not overtightened.
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Refill and Bleed: Refill the power trim pump reservoir with the manufacturer-recommended hydraulic fluid. Cycle the trim up and down several times to bleed air from the system, checking the fluid level and topping off as needed.
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Check for Leaks: With the system pressurized, carefully inspect all connections for any signs of hydraulic fluid leaks before returning the vessel to service.
Troubleshooting & FAQ
How do I confirm this fits my engine?
This kit is designed for a wide range of MerCruiser drives from 1983 and newer, including MC-1, R, MR, Alpha One Gen 2, and Bravo series. The best way to confirm fitment is to match your existing part number to those in our cross-reference list, such as 8M0137703, 8M0080805, or 98825A4.
What are the signs that my hydraulic manifold needs to be replaced?
Common symptoms of a failing manifold include visible hydraulic fluid leaks around the connector block, a spongy or unresponsive trim/tilt system, or obvious physical damage like cracks or heavy corrosion on the aluminum housing.
Is this a complete kit for the job?
Yes, this is a comprehensive replacement kit that includes the manifold block, plate, mounting bolts, lockwashers, and the necessary gaskets. You will only need basic hand tools and the appropriate MerCruiser power trim hydraulic fluid.
OEM vs. Aftermarket?
This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.
How fast do you ship and how much does it cost?
We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.
What is your warranty and return policy?
This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.
Important Notes
- Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
- This product is an aftermarket replacement part and is not an OEM component.
- Professional installation is recommended to ensure safety and optimal performance.
Why Choose JLM MARINE?
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Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
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Fast Global Shipping: Free delivery worldwide in 5–15 days.
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Direct from Manufacturer: Competitive pricing without compromising quality.