16321-75020 Water Inlet Thermostat Housing for Toyota

16321-75020 is a compact aluminium coolant inlet positioned at the thermostat connection point in selected Toyota cooling circuits. AutoParts records the part as THH260727-001 for B2B enquiry, sample review and shipment traceability.

The supplied application reference includes Toyota Hilux Vigo, Hilux Revo, Fortuner, Hiace and Prado source references. Since the list spans several vehicles or platforms, the Model filter is intentionally blank and final fitment should rely on vehicle-specific evidence.

Product Technical Specifications

Product type: Engine Coolant Water Inlet / Thermostat Housing

Primary OE reference: 16321-75020

Internal item code: THH260727-001

Vehicle brand: TOYOTA

Model filter: Intentionally blank; confirm by VIN and engine data

Cross-reference numbers: 16321-75020

Construction: machined aluminium water inlet with a three-bolt mounting flange and coolant hose neck

Approval method: OE catalogue, VIN, engine information and original-part comparison

A Stable Coolant Entry Point for Toyota Engines

This housing forms the transition between the coolant hose and the engine-side thermostat passage. Its machined flange must sit squarely so the seal can maintain pressure as coolant temperature rises.

The straight outlet neck and internal bore should preserve the intended flow path without creating a restriction. Dimensional consistency is especially important where similar Toyota engines use different flange patterns.

Toyota Flange and Water-Neck Matching

Confirm 16321-75020 through the VIN catalogue, engine family and production date. Place the removed part beside the replacement and compare all three bolt centres, the seal groove and the angle of the hose neck.

Check whether the original installation uses an O-ring, formed gasket or thermostat-mounted seal. Do not approve interchange from the outer silhouette alone.

Machined Surface and Leak-Control Inspection

Inspect the casting for porosity, impact marks and burrs around the coolant passage. The flange face should be clean and free from distortion that could prevent even gasket compression.

During service, clean the mating surface, install the specified seal and tighten fasteners in stages. Pressure-test the circuit and recheck the joint after the first full warm-up.

Procurement, Packing and Sample Confirmation

Reference 16321-75020 as the OE identifier and THH260727-001 as the internal item code. Include required volume, destination, carton marking and label format in the quotation request.

Before batch supply, buyers may submit VIN data, engine information, measurements and photographs of the removed component. A physical sample can be used when catalogue evidence is incomplete.

Frequently Asked Questions

What is Toyota OE 16321-75020 used for?

It identifies a coolant water-inlet housing at the thermostat connection, linking the hose path to the engine cooling passage.

Which measurements are most important before ordering?

Compare the three mounting holes, flange outline, seal recess, bore size, hose-neck diameter and outlet direction.

Why is the Toyota Model filter blank?

The source lists several Toyota platforms, so VIN, engine and production-date confirmation is more reliable than one model selection.

Can an old seal be reused?

A new application-correct seal is recommended because a compressed or hardened seal can allow coolant leakage after installation.

How should wholesale buyers request a sample?

Quote 16321-75020 and THH260727-001 with quantity, destination, packing needs and photos or dimensions of the original housing.

Request a 16321-75020 Thermostat Housing Quote

Contact AutoParts with OE 16321-75020, item code THH260727-001, quantity and delivery market. Complete fitment confirmation before production ordering or workshop installation.

Application reference: Toyota Hilux Vigo, Hilux Revo, Fortuner, Hiace and Prado source references; verify compatibility through VIN, engine data and original-part comparison.

Inspection focus: mounting-hole spacing, sealing recess, internal bore, hose-neck diameter, flange flatness and casting finish

Supply note: Use THH260727-001 for quotations, sample approval, packaging and order traceability.