Radiator Assembly 16400-17231 1640017231 For Toyota Coaster HZB50 HZB40 1HZ Diesel 1999-2016 — OEM Aluminum Core Cooling Radiator

✅ Product Description

The Radiator Assembly with OEM number 16400-17231 (also listed as 1640017231) is a verified OEM-grade direct replacement for Toyota Coaster buses equipped with the 1HZ 4.2L diesel engine. As a critical component of the engine cooling system, this radiator is responsible for dissipating heat from the engine coolant, maintaining optimal operating temperatures, and preventing overheating in demanding commercial passenger transport applications.

This radiator is the base parent part number for the 1HZ..HZB50 variant, with 16400-17232 serving as the current production replacement-2. It features a high-efficiency aluminum core designed for maximum heat transfer and long service life under the rigorous demands of continuous commercial operation.

• ✅ OEM Specification — Verified by Toyota OEM part number 16400-17231 (Parent Part Number) and compatible replacement 16400-17232-2.

• ✅ Verified OEM Fitment — Confirmed for Toyota Coaster HZB50 with 1HZ engine, Right-Hand Drive, 5-Speed Manual Transmission (MTM), produced 1993-01 » 2016-12-2.

• ✅ Proven Compatibility — Also applicable to Coaster HZB40 and BB50R/BB42 (14B/15BFT) variants-4.

• ✅ OEM Cross-Reference Verified — Replaces 16400-17230 (05/1997-02/1999) and is superseded by 16400-17232 (2004-08 » 2014-04)-2-18.

• ✅ Constructed from High-Quality Materials — Aluminum core with brazed cooling fins for superior heat dissipation and structural integrity-8.

[Failure Symptoms]
If your radiator is failing, you may experience one or more of the following symptoms:

1. Engine Overheating: Temperature gauge consistently rising above normal operating range — the most common sign of a clogged or leaking radiator-1.

2. Coolant Leakage: Visible coolant puddles under the vehicle or damp spots on the radiator core — indicates cracks or seam failure.

3. Steam from Engine Bay: Steam or vapour rising from the radiator area, especially after heavy load or extended operation-1.

4. Coolant Loss: Unexplained drop in coolant level with no visible external leaks — may indicate internal core leakage.

5. Reduced Heater Performance: Cabin heater blowing cold air — indicates insufficient coolant circulation.

⚠️ A failing radiator can lead to severe engine damage including blown head gaskets, warped cylinder heads, or complete engine seizure-1 — prompt replacement is essential to maintain engine reliability and prevent costly repairs.

✅ Vehicle & Engine Compatibility

⚠️ CRITICAL: This radiator is designed for the Toyota Coaster with 1HZ diesel engine. Please verify your vehicle's engine code and chassis code before ordering.

Primary Applications:

Associated Components (Sold Separately):

⚠️ Important:

• This radiator is designed for Toyota Coaster models with 1HZ, 14B, 15BFT, and 1BZFPE diesel engines.

• Supersession Note: 16400-17231 has been superseded by 16400-17232 for current production. Both part numbers are interchangeable for the applications listed-2.

• The 16400-17231 was used from 03/1999 to 06/1999 as a direct replacement for 16400-17230-18.

• Please verify your vehicle's chassis code, production year, and VIN before ordering.

✅ Features & Benefits

✅ Quality Control & Verification

Our manufacturing and inspection processes ensure every radiator meets or exceeds Toyota OEM standards.

✅ Installation & Maintenance Recommendations

⚠️ IMPORTANT: Professional Installation Recommended

• Pre-Installation Checklist:

  • Ensure the engine is completely cool before starting work.

  • Drain the coolant system properly and dispose of coolant according to local regulations.

  • CRITICAL: Verify your vehicle's engine code (1HZ) and chassis code (HZB50/HZB40) before ordering.

  • Inspect all radiator hoses, clamps, and the thermostat for wear or damage — replace as necessary.

  • Clean the radiator mounting area of debris and old gasket material.

  • Note: Radiator cap, expansion tank, and gasket are not included — transfer from the old unit or purchase separately.

Installation Guidelines (Reference Toyota workshop manual):

1. Ensure the engine is cool and drain the cooling system.

2. Disconnect the negative battery terminal.

3. Remove the radiator hoses from the old radiator (note positions for reinstallation).

4. Disconnect any electrical connectors (coolant temperature sensor, fan, etc.).

5. Remove the radiator mounting bolts and brackets.

6. Carefully remove the old radiator from the vehicle.

7. Transfer any mounting brackets, fans, or shrouds to the new radiator.

8. Install the new radiator in the correct orientation.

9. Secure with mounting bolts and torque to manufacturer's specified torque settings (refer to Toyota workshop manual).

10. Reconnect all radiator hoses securely using new clamps if necessary.

11. Reconnect all electrical connectors.

12. CRITICAL: Refill the cooling system with the correct coolant mixture (refer to workshop manual for specifications).

13. CRITICAL: Bleed the cooling system to remove air pockets (refer to workshop manual for the correct procedure).

14. Start the engine and allow it to reach operating temperature.

15. Check for coolant leaks and verify the cooling fan operates correctly.

Maintenance Schedule:

• Inspection: Every 50,000 km / 12 months. Check for coolant leaks, debris buildup on the core, and corrosion.

• Coolant Replacement: Every 2 years or 40,000 km — replace coolant to prevent internal corrosion and maintain cooling efficiency.

• Replacement: Immediately if failure symptoms appear or if the radiator shows signs of significant corrosion or damage.

• Note: A failing radiator can cause engine overheating, which may lead to complete engine failure if not addressed promptly-1.

✅ Packaging & Supply

• Packaging: Each radiator is securely packed in a heavy-duty carton with foam inserts to prevent shipping damage.

• Note: Radiator cap, expansion tank, and gasket are not included.

• Suitable for: Wholesale distributors, auto parts retailers, commercial vehicle repair shops, and fleet owners.