8M0137703 Trim Line Manifold for Mercury MerCruiser Alpha Bravo | JLM Marine

Trim Line Manifold for Mercury MerCruiser Alpha Bravo – 8M0137703

This Trim Line Manifold is designed for MerCruiser Alpha One Gen I & Gen II sterndrives (1972–1990) and MerCruiser R/MR/Bravo drives (1983 and newer). It serves as a critical hydraulic connector for the trim system, ensuring reliable fluid routing and proper outdrive operation.

This aftermarket replacement directly replaces Mercury MerCruiser OEM part numbers 98825A4, 8M0080805, 8M0137703, and 98825A12. It is compatible with most MerCruiser outdrives that use 1/4" tube fittings from 1983 onward.

• Complete manifold assembly kit with all necessary mounting hardware and gaskets
• Fits hydraulic trim hoses on MerCruiser outdrives with 1/4" tube fittings (1983–present)
• Essential component for maintaining proper trim and tilt function

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

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.

Technical Specifications

Package Contents

This trim line manifold kit includes the following components:

• 1 × Plate
• 1 × Junction block body
• 2 × Gaskets
• 2 × Lockwashers
• 2 × Mounting bolts

Installation Guide

1. Disconnect the battery and relieve hydraulic pressure from the trim system before beginning work.
2. Remove the old trim line manifold by disconnecting the hydraulic lines and unbolting the mounting hardware. Be prepared for minor fluid spillage.
3. Clean the mounting surface thoroughly to remove old gasket material and debris.
4. Position one new gasket on the mounting surface, aligning all bolt holes.
5. Install the junction block body onto the gasket, ensuring proper alignment with hydraulic line ports.
6. Place the plate over the junction block body with the second gasket in between.
7. Insert the two mounting bolts with lockwashers and tighten in a cross-pattern to ensure even compression. Do not overtighten.
8. Reconnect all hydraulic trim lines to the appropriate ports on the manifold, ensuring connections are snug and leak-free.
9. Bleed air from the hydraulic trim system according to your engine's service manual.
10. Reconnect the battery and test the trim function through its full range of motion.
11. Inspect all connections for leaks while the system is under pressure.
12. If any leaks are detected, relieve pressure, retighten connections, and retest. Professional installation is recommended if you are unfamiliar with hydraulic systems.

Troubleshooting & FAQ

Q: How do I confirm this manifold fits my MerCruiser outdrive?
A: Check your outdrive model and year against the compatibility table above. This manifold fits Alpha One Gen I & Gen II (1972–1990) and R/MR/Bravo drives (1983–up) that use 1/4" hydraulic tube fittings. You can also cross-reference your existing part number with 98825A4, 8M0080805, 8M0137703, or 98825A12.

Q: What are the signs that my trim line manifold needs replacement?
A: Common symptoms include hydraulic fluid leaks around the manifold, slow or erratic trim/tilt operation, loss of trim function, or visible corrosion and damage to the manifold body or fittings.

Q: Do I need to bleed the hydraulic system after installing this manifold?
A: Yes, bleeding the trim system is essential after installation to remove air that may have entered during the replacement process. Follow your engine's service manual for the proper bleeding procedure to ensure optimal trim performance.

Q: Can I install this manifold myself or do I need a professional?
A: If you have mechanical experience and are comfortable working with hydraulic systems, you can install this yourself following the installation guide. However, professional installation is recommended to ensure proper sealing, correct torque specifications, and thorough system bleeding.

Q: Is this an OEM part or aftermarket?
A: 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.

Q: How fast do you ship and how much does it cost?
A: 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.

Q: What is your warranty and return policy?
A: 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?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.