Mercury MerCruiser Quicksilver 16792A39 Power Steering Pump — Without Pulley

Mercury MerCruiser Quicksilver 16792A39 — Power Steering Pump, Without Pulley

Overview

Mercury MerCruiser Quicksilver 16792A39 is a genuine OEM power steering pump for selected MerCruiser V6 and V8 gasoline engines equipped with hydraulic power steering. It provides the hydraulic pressure for the steering system and is the direct OEM replacement for earlier pump assemblies 16792A33, 16792A1, and 90496A5. The pump is supplied as the pump assembly only — the pulley is not included and must be transferred from the original pump or purchased separately.

Important: The pulley, belt, bracket, and hose configuration must match the specific engine and serial-range setup. Engine displacement alone is not sufficient to confirm fitment. Always verify by exact engine model, serial number, and the Mercury steering-components parts diagram before ordering.

Kit Contents

• Power steering pump assembly — 1
• Studs — 2
• Cap — 1
• Pulley not included — must be installed separately

Supersession

• Current part number: 16792A39
• Supersedes: 16792A33
• Supersedes: 16792A1
• Earlier assembly reference: 90496A5
• Cross-reference: Volvo Penta 855860 (confirm applicability by serial number)
• If your diagram or service records show any of the above earlier numbers, 16792A39 is the current OEM replacement.

Compatible Applications

• MerCruiser 4.3L V6 — hydraulic power steering equipped (confirm serial range)
• MerCruiser 4.3L EFI / TBI V6 — hydraulic power steering equipped (confirm serial range)
• MerCruiser 4.3L MPI Alpha / Bravo V6 — hydraulic power steering equipped (confirm serial range)
• MerCruiser 5.0L V8 Alpha / Bravo — hydraulic power steering equipped (confirm serial range)
• MerCruiser 5.7L V8 Alpha / Bravo — hydraulic power steering equipped (confirm serial range)
• Always confirm by exact engine model, serial number, and steering-components diagram — MerCruiser used different pump, pulley, bracket, and belt arrangements across similar V6 and V8 applications

When to Replace

• Persistent whining or growling from the pump during steering input
• Fluid leaking from the pump body, shaft seal, or hose connections
• Heavy or inconsistent steering effort despite correct fluid level
• Foamy, discolored, or contaminated power steering fluid after the reservoir and lines have been inspected
• Loss of hydraulic assist in one or both steering directions
• Pump confirmed failed after diagnosis of the full steering system (cylinder, hoses, helm, fittings)

Installation Notes

• Pulley not included — transfer the correct pulley from the original pump, or order the correct replacement pulley (8M0150723 for later applications; 861578 for earlier). Confirm which pulley applies to your engine by serial number
• Use the correct pulley removal and installation tool — pressing or hammering the pulley onto the new pump shaft without the proper tool can bend the shaft or damage the pump seal
• Inspect the belt, bracket, hoses, fittings, and reservoir before installing the new pump — a worn belt or cracked hose will affect performance after installation
• Check power steering fluid condition and flush the system if fluid is contaminated — contaminated fluid will shorten the life of the new pump
• Bleed the power steering system according to the Mercury service procedure for the specific engine after installation to remove air from the hydraulic circuit
• Confirm correct belt tension and pulley alignment after installation before running the engine

Technical FAQ

• Why is the pulley not included? Mercury supplies this pump as a bare assembly because different engine setups, belt routing configurations, and pulley specifications can apply across the compatible engine family. The correct pulley must be confirmed by engine model and serial number and is sold separately (8M0150723 for many later applications).
• Can I use a generic automotive power steering pump? Not recommended. Shaft dimensions, port locations, hose fitting sizes, reservoir configuration, mounting bracket geometry, and operating pressure characteristics are matched to the original MerCruiser installation. A generic automotive pump may physically mount but will likely require modifications and may not deliver the correct hydraulic pressure for the MerCruiser steering system.
• How do I confirm which pulley I need? Check the steering-components diagram for your exact engine model and serial number in the Mercury parts catalog. The diagram will identify the correct pulley part number — 8M0150723 is current for many later applications, replacing earlier 861578, but confirm by your specific serial range.
• What causes power steering pump failure on MerCruiser engines? The most common causes are fluid contamination (water intrusion, worn fluid), running the system with low fluid level, a worn or glazed drive belt that causes belt slip and pump overspin, and hose or fitting leaks that allowed air into the system over time. Before installing a new pump, inspect all components in the system to identify and correct the root cause.
• Do I need to flush the system before installing the new pump? If the old pump failed due to seal or internal wear, yes — debris from the failed pump can circulate through the system and damage the new pump. Flushing the reservoir, hoses, and steering cylinder before installation is good practice whenever a pump has failed rather than simply worn out from age.

Parts Desk Insights

Best Use Case: This pump is the right replacement when the original MerCruiser hydraulic steering pump is confirmed failed and the rest of the steering system (hoses, cylinder, helm, fittings) has been inspected and is serviceable. The key advantage of using the OEM Mercury pump is that the shaft dimensions, port geometry, mounting hardware, and pressure characteristics are exactly matched to the original installation — which makes the swap straightforward and preserves the original steering response.

Common Issues: The most frequent mistake is not confirming which pulley is needed before starting the job — the pump arrives without a pulley, and if the correct replacement pulley is not on hand, the installation cannot be completed. Order the correct pulley (confirm 8M0150723 or 861578 by serial number) at the same time as the pump. The second common issue is skipping a system flush when replacing a pump that failed due to contamination — debris left in the hoses or cylinder will damage the new pump within a short service period.