Sierra 18-0891-9 Water Pump Mounting Gasket, Replaces 27-34897, GM 4.3L 5.0L 5.8L, Pack of 2

The Sierra 18-0891-9 Water Pump Mounting Gasket seals the water pump housing to the engine block on GM 4.3L, 5.0L, and 5.8L marine engines. Sold in a package of 2, this gasket is built to meet or exceed original equipment quality, giving a reliable, leak-free seal at the pump-to-block mating surface during routine water pump service, rebuilds, or replacement. Keeping a spare on hand is worthwhile since the gasket should always be replaced whenever the water pump is removed, rather than reused.

This mounting gasket is a direct cross-reference match for several OEM and aftermarket numbers, so it fits in place of the Mercruiser 27-34897, 27-34896, FI5000077, and FI5000078 gaskets used on the same GM-based engine platforms. Because it ships two to a package, one purchase covers both sides of a dual-pump job or provides a spare for the next service interval. As with any gasket, proper surface prep on the block and pump housing before installation helps ensure a tight, long-lasting seal.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-0891-9
• Product Type: Water Pump Mounting Gasket
• Package Quantity: Pack of 2
• Engine Fitment: GM 4.3L, 5.0L & 5.8L
• Weight: 0.01 pounds
• UPC: 808282161897
• OEM Cross-Reference: 27-34897, 27-34896, FI5000077, FI5000078
• Warranty: 90 days

Fitment

• GM 4.3L, 5.0L & 5.8L engines

Replaces (OEM)

• 27-34897
• 27-34896
• FI5000077
• FI5000078

Frequently Asked Questions

What engines does the Sierra 18-0891-9 water pump mounting gasket fit? The Sierra 18-0891-9 is designed for GM 4.3L, 5.0L, and 5.8L marine engines.

How many gaskets come in a package of 18-0891-9? Each package of the Sierra 18-0891-9 water pump mounting gasket contains 2 gaskets.

Is the Sierra 18-0891-9 gasket a genuine OEM part or an aftermarket replacement? It is a Sierra-manufactured aftermarket replacement gasket, made to meet or exceed original equipment quality rather than being a Mercruiser-branded OEM part.

Which Mercruiser part numbers does the 18-0891-9 gasket cross-reference? It replaces Mercruiser 27-34897, 27-34896, FI5000077, and FI5000078.

Do I need to replace this gasket every time I service the water pump? Yes, a water pump mounting gasket like the Sierra 18-0891-9 should be replaced whenever the water pump is removed, since a used gasket will not reseal reliably.

What is included when I order the 18-0891-9? Ordering the Sierra 18-0891-9 gets you a package of 2 water pump mounting gaskets sized for GM 4.3L, 5.0L & 5.8L engines; no additional hardware is included.

How much does the Sierra 18-0891-9 gasket weigh? The Sierra 18-0891-9 water pump mounting gasket weighs 0.01 pounds.

What warranty applies to the Sierra 18-0891-9? The Sierra 18-0891-9 water pump mounting gasket carries a 90 day warranty.

Can I use the 18-0891-9 gasket on an engine other than GM 4.3L, 5.0L, or 5.8L? The 18-0891-9 is specified for GM 4.3L, 5.0L & 5.8L engines; fitment outside that range is not confirmed.

Does the 18-0891-9 come as a single gasket or a set? The 18-0891-9 is sold as a set, packaged 2 gaskets per unit.