Sierra 18-70931 Molded Hose, Distribution Block to Water Pump, Replaces 32-96879, Fits Mercruiser MCM 120/2.5L, 140/3.0L, 160/165

The Sierra 18-70931 Molded Hose is a purpose-shaped cooling system hose that runs from the distribution block to the water pump on applicable Mercruiser I/O engines. Unlike a straight-cut length of hose, this molded hose is formed to the exact bend and routing needed for this connection point, so it seats correctly without kinking or requiring extra clamps to hold a shape. It is built from a rubber and plastic construction in white, sized to a nominal wall thickness of 0.12 inches, and is designed to fit Mercruiser MCM 120/2.5L, 140/3.0L, and 160/165 applications. As a direct cross-reference to Mercruiser Stern Drive part number 32-96879, it restores factory cooling flow between the distribution block and water pump and is intended to meet or exceed the performance of the original equipment part it replaces. This hose is a straightforward maintenance-and-repair item for boat owners servicing the cooling circuit on a compatible Mercruiser engine, whether replacing a cracked, hardened, or leaking original hose or restoring a system after other cooling work.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-70931
• Product Type: Molded Hose
• Application: Distribution block to water pump
• Material: Plastic, Rubber
• Color: White
• Nominal Wall Thickness: 0.12 inches
• Weight: 0.7 pounds
• UPC: 808282145934
• Fitment: Mercruiser MCM 120/2.5L, MCM 140/3.0L, MCM 160/165
• Replaces (OEM): 32-96879

Fitment

• Mercruiser MCM 120/2.5L
• Mercruiser MCM 140/3.0L
• Mercruiser MCM 160/165

Replaces (OEM)

• 32-96879

Frequently Asked Questions

What does the Sierra 18-70931 Molded Hose connect? The 18-70931 Molded Hose runs from the distribution block to the water pump in the engine cooling circuit.

Which engines does the 18-70931 fit? It is designed to fit Mercruiser MCM 120/2.5L, MCM 140/3.0L, and MCM 160/165 applications.

Is the 18-70931 a direct replacement for a Mercruiser OEM hose? Yes, it cross-references to Mercruiser Stern Drive part number 32-96879 and is built to meet or exceed the performance of that original part.

What material is the 18-70931 Molded Hose made from? It is made from a rubber and plastic construction, finished in white, with a nominal wall thickness of 0.12 inches.

How much does the 18-70931 hose weigh? The Sierra 18-70931 Molded Hose weighs 0.7 pounds.

Why is this hose molded instead of a straight length? The 18-70931 is molded to the specific bend needed between the distribution block and water pump, so it routes correctly without kinking rather than relying on a cut length of straight hose.

When should I replace the 18-70931 distribution block hose? Replace it when the original distribution-block-to-water-pump hose on a compatible Mercruiser engine shows cracking, hardening, or leaking, which are common signs of a worn cooling hose.

Does the 18-70931 include any clamps or fittings? The listing covers the Sierra 18-70931 Molded Hose itself; no additional components are specified.

What is the UPC for the Sierra 18-70931 hose? The UPC for the Sierra 18-70931 Molded Hose is 808282145934.

Is the Sierra 18-70931 an OEM or aftermarket part? It is an aftermarket Sierra part manufactured to meet or exceed the original equipment hose it replaces, cross-referencing Mercruiser 32-96879.