Installing a new radiator in your Honda Acty—whether it’s a carbureted HA3/HA4 or EFI HA6/HA7 model—is a manageable DIY job that can prevent serious overheating issues and extend engine life. Radiators in the Acty can become clogged, corroded, or start leaking over time, especially in older vehicles or those driven in hot climates. To begin, you'll need basic tools like a 10mm socket set, pliers, a drain pan, and possibly a fluid funnel or coolant bleeder. First, make sure the engine is completely cool, then drain the old coolant by opening the radiator cap and lower drain plug or hose. Remove the front grille or service panel to access the radiator, disconnect the upper and lower hoses, and detach any fan wiring or shrouds. After unbolting the old radiator, install the new one—making sure it matches your Acty’s engine and year. Common part numbers include 19010-PZ3-003 for HA3/HA4 and 19010-PFB-003 for HA6/HA7, but always verify using your VIN. Reconnect hoses, refill the system with Honda-compatible coolant, and bleed out air pockets by running the engine with the heater on full. Watch the temperature gauge during the first few drives, and recheck coolant levels after it cools. Replacing the radiator is a great time to inspect the thermostat, cap, and hoses, and with proper care, your Acty will stay cool and dependable for years to come.