32-87108 1-3/4-Inch Circulating Pump Molded Hose · Fits MerCruiser 4.3L 5.0L 5.7L V6/V8 cooling systems, Replaces 18-71337, 32-33189

32-87108 1-3/4-Inch Circulating Pump Molded Hose · Fits MerCruiser 4.3L 5.0L 5.7L V6/V8 cooling systems, Replaces 18-71337, 32-33189

GHMarine molded circulating-pump hose for select 4.3L / 5.0L / 5.7L MerCruiser / GM / OMC marine cooling routes. Primary OEM is 32-87108 (legacy 32-33189); common cross-ref 18-71337. Catalog size: 1-3/4-inch I.D., about 12-3/4-inch tall. The molded bend path is part of the fit — a same-I.D. straight hose is not a substitute.

This hose body is no-drain. Some catalogs also list 18-71337 / 32-87108 as a replacement for drain-equipped assemblies 32-861590A05 / A2 / A1 — that is a catalog cross, not a physical twin. If your old hose has a drain, confirm the engine cooling design and how the drain function will be handled before ordering.

Ships as one molded circulating-pump hose. Clamp count is not locked on this page — confirm against your package. Engine-bay cooling hose — not a sterndrive transom water-intake hose.

Which hose is this?

It is the molded circulating-pump hose on the engine-side cooling circuit for select V6/V8 layouts that specify 32-87108 / 32-33189 / 18-71337. It routes coolant / raw water along the designed bend around nearby parts.

It is not the short U hose for 2.5L/3.0L inline-4 (8M0071007 — GH 18H1004), not a starboard manifold hose (32-871171), and not a Bravo/Alpha transom intake hose (32-43437 / 32-41725-33).

Signs yours is due

• 4.3 / 5.0 / 5.7L engine bay: the tall 1-3/4-inch circulating-pump hose is heat-glazed, bubbled, or cooked after an impeller / raw-water blockage event.
• Salt trails drip from the circulating-pump hose ends — not from a Bravo/Alpha transom intake and not from the short 2.5/3.0L U hose.
• Old assembly was a drain-equipped 32-861590A05 / A2 / A1: catalogs may cross to 18-71337, but this replacement body has no drain — confirm cooling design first.
• Divert: short U between distribution block and pump on 2.5/3.0L → GH 18H1004. Same-I.D. straight hose cut to length is not a substitute for this molded path.

Will it fit my drive?

This molded hose is Compatible with select MerCruiser / GM / OMC 4.3L V6 / 5.0L V8 / 5.7L V8 cooling systems that specify 32-87108, 32-33189, or 18-71337. Displacement alone does not prove fit — confirm original hose number, 1-3/4-inch I.D., ~12-3/4-inch height, bend geometry, drain configuration, engine model, and serial.

Final fit = original hose number + I.D. + height + bend path + drain decision + engine/SN / EPC — not "4.3/5.0/5.7L" alone.

OEM & swap numbers

Primary no-drain family: 32-87108 / legacy 32-33189 / cross-ref 18-71337. Catalog may also list 18-71337 against drain assemblies 32-861590A05 / A2 / A1 and 32-806825 — read the drain note above before treating those as drop-in identical.

Wrong part? Read before you order

• NOT an unconditional twin of drain hose 32-861590A05 / A2 / A1 — catalog cross only; this body has no drain
• NOT 2.5L/3.0L short U hose 8M0071007 / 18-70931 (GH 18H1004)
• NOT starboard manifold hose 32-871171 / 18-70932
• NOT transom / bell-housing intake 32-41725-33 / 32-43437 (GH 18H1003 / 18H1001)
• NOT adjacent molded family 32-860144 / 18-70940
• NOT a same-I.D. straight hose cut to length — molded bend is required

What ships in the box

• 1 × Molded circulating-pump hose (32-87108 / 18-71337 family · no drain)
• Clamps: not locked as a fixed outbound BOM on this page — confirm quantity against your package

Often ordered with related SKUs

• 2.5L/3.0L circulating-pump U hose → GH 18H1004
• Bravo Design I water intake hose → GH 18H1001
• Alpha / bell-housing water hose family → GH 18H1003 / 19H1002 (confirm identity before ordering)

Install tips in the engine bay

Engine-bay cooling-hose work. Cold engine; disconnect battery; relieve pressure and drain coolant / antifreeze per the service manual. This is not a sterndrive bellow job — do not use bellows adhesive or a bellows expander.

1. Photograph and mark the old hose orientation, bend path, clamp lands, and whether a drain was present.
2. Confirm the new hose is 32-87108 / 18-71337 no-drain family with matching I.D., height, and molded path — do not force a different bend.
3. Clean mating tubes; check corrosion, burrs, and deformation; replace damaged clamps if needed.
4. Seat the hose fully; place clamps on the correct lands; tighten to the engine service-manual specification (no universal torque invented here).
5. Refill / restore the cooling circuit, burp air per the manual, then run to temperature and check for leaks or hose collapse.

FAQ

Does this hose have a drain?

No. The 32-87108 / 18-71337 hose body sold as 18H1006 is no-drain. If your old part is 32-861590A05 / A2 / A1 (drain assembly), catalogs may still cross-list 18-71337 — that does not make the two hoses physically identical. Confirm how the drain function will be handled on your engine.

Will this fit every 4.3 / 5.0 / 5.7L MerCruiser?

No. Same displacement can use different cooling designs, hose routes, and drain layouts across years. Match the OEM number, I.D., height, bend, and serial.

Is this the same as 18H1004?

No. 18H1004 is the short U hose for 2.5L/3.0L inline-4 (8M0071007). This SKU is the taller 1-3/4-inch V6/V8 circulating-pump molded hose (32-87108).

How many clamps are included?

This page locks only the molded hose. Clamp count is not a fixed outbound BOM here — check your package photo / packing slip.

Can I use a straight hose of the same I.D.?

No. The molded bend clears nearby parts and keeps the route from kinking. A straight cut hose is not a correct substitute for this application.

Do I need bellows adhesive or an expander?

No. This is a cooling molded hose, not a sterndrive exhaust bellow. Follow the cooling-system service method for your engine.

Please note

Aftermarket replacement by GHMarine. Not affiliated with engine manufacturers named above. "Compatible with", "Replaces", and catalog crosses identify the 32-87108 / 18-71337 no-drain family — always confirm hose number, geometry, drain decision, serial, and package contents before ordering.