Parts for your 2002 Daihatsu Gran move-Radiator cap

Radiator cap for the 2002 Daihatsu Gran Move

For the 2002 Daihatsu Gran Move, a radiator cap is definitely fitted and relevant. Daihatsu’s G300/G303 Gran Move (Pyzar) workshop manual cooling system section and the Daihatsu Electronic Parts Catalogue list a radiator filler cap as a replaceable component on the radiator neck, with a specified pressure rating. That confirms this model uses a traditional pressurised radiator cap rather than a sealed, cap‑on‑tank arrangement.

On this Gran Move, the radiator cap does a lot more than just close the filler neck. It seals the cooling system so it can run under pressure, which raises the coolant’s boiling point and helps prevent overheating on hot days or long climbs. The spring-loaded valve inside the cap also relieves excess pressure to the overflow bottle when things get toasty, then draws coolant back in as the engine cools. When the cap’s in top nick, it keeps temperatures stable, prevents air leaks, and helps the heater and water pump do their jobs without dramas.

Because it works hard every time the car heats up and cools down, the cap is a small part that can cause big headaches if it’s tired. If the rubber seal is cracked, the spring’s weak, or the valve sticks, you might see coolant loss, overheating in traffic, a collapsed lower radiator hose after shut-down, or burbling in the overflow bottle. A quick cap test with a pressure tool will tell you if it’s holding the correct kPa, but replacing a suspect cap is often the quickest win.

• Always check or remove the cap only when the engine is stone cold. Twist to the first detent to vent, then remove.
• Match the cap’s pressure rating to the spec on the old cap, the bonnet decal, or the owner’s manual (commonly around 0.9 bar for many Daihatsus).
• Inspect the filler neck for nicks or corrosion and make sure the overflow hose and bottle are clean and clear.
• If you’re servicing the cooling system (new coolant, hoses, thermostat), it’s smart to fit a fresh, quality cap at the same time.

Looking after the radiator cap on a 2002 Gran Move is simple, affordable, and a sweet way to keep the cooling system reliable through Kiwi summers and Aussie heat.

Popular questions about 2002 Daihatsu Gran Move radiator caps

What pressure rating should the radiator cap be?
Most Gran Move examples run a cap around 0.9 bar (about 88–90 kPa), but always confirm against the stamping on your existing cap, the bonnet sticker, or the owner’s/service manual. Using the correct rating is important for boiling point, hose life, and proper coolant return.

How often should the radiator cap be replaced?
If it’s original or older than four years, replace it during your next coolant service. Replace sooner if you notice coolant loss to the overflow bottle, overheating in traffic, or perished seals. A new cap is cheap insurance and pairs well with fresh coolant and a thermostat check.

What are the signs of a faulty radiator cap?
Tell-tales include a collapsed lower hose after cooldown, gurgling in the overflow bottle, coolant smell without visible leaks, random temp swings, or heater performance dropping off. A cap test with a cooling system tool will confirm if it’s failing to hold the specified pressure.