Cooling System

Chapter 6 - Cooling System

Once sufficient access had been gained around the engine, the radiator, header tank and associated pipework were removed to allow the complete cooling system to be inspected.

Removing the assembly also created the opportunity to clean years of accumulated dirt and surface corrosion from areas of the engine bay that would otherwise remain inaccessible. Every bracket, mounting point and fastener was inspected as components were removed, allowing any corrosion or damaged hardware to be addressed before reassembly.

Rather than treating the radiator as a single component, the entire cooling system was considered as an assembly, with each individual part assessed on its own condition.

Figure 2 – Radiator and cooling components removed

Figure 3 – Engine bay after radiator removal

Reverse Flushing the System

With the cooling system dismantled, both the engine block and radiator were reverse flushed several times to remove old coolant, rust particles and accumulated sediment.

Although flushing is often viewed as a simple maintenance task, it also provided an indication of the internal condition of the system before fresh coolant was introduced. Establishing a clean starting point means future maintenance and coolant condition can be monitored with far greater confidence.

While the system was apart, all coolant pipes, brackets and mounting hardware were cleaned and prepared for refinishing prior to reassembly.

Figure 4 – Reverse flushing the engine block

Figure 5 – Cleaning cooling system components

Thermostat Testing

Since the thermostat had already been removed, it made sense to confirm its performance

The thermostat was tested in heated water while its opening temperature was monitored using an infrared thermometer. It commenced opening at approximately 71°C, which was consistent with the manufacturer's specification and confirmed the unit remained serviceable.

Confirming the condition through testing eliminated unnecessary replacement while maintaining confidence in the cooling system's ability to regulate engine operating temperature.

Figure 6 – Thermostat bench testing

Radiator Assessment

Following cleaning and flushing, the radiator was prepared for professional inspection and testing.

While external condition can reveal obvious damage, it provides little indication of the internal condition of the core. Rather than making assumptions, the radiator was sent to a specialist for testing to confirm its suitability for continued service.

While the radiator was away, the remaining cooling system components were refurbished, ensuring the entire assembly would be ready for reinstallation once testing had been completed.

The original radiator had significant corrosion on the external lower fins, even though it passed the pressure test i decided to replace it with another unit.

The second hand sourced radiator passed inspection and was considered suitable for continued service.

Figure 7 – Radiator prepared for testing

Figure 8 – Radiator after inspection

Component Refurbishment

With the major cooling components removed, \attention turned to restoring the surrounding hardware.

The cooling fan, pulley assemblies and mounting brackets were sandblasted, treated for corrosion and repainted before reassembly. Associated engine bay wiring was rerouted and protected where required, while every accessible threaded hole was cleaned to improve assembly quality and ensure accurate bolt torque.

Although much of this work is rarely noticed once the vehicle is complete, restoring these supporting components contributes significantly to both the reliability and ease of future maintenance.

Figure 9 – Cooling fan refurbishment

Figure 10 – Restored brackets and hardware