Parts for your 2000 Daihatsu Gran move-Heater tap

2000 Daihatsu Gran Move heater-tap: purpose, servicing and replacement

Based on Daihatsu G300-series technical literature — specifically the Pyzar/Gran Move workshop manual Heating & Ventilation section and the Daihatsu Electronic Parts Catalogue (EPC) listings for “water cock” (heater water valve) on 2000 models — this vehicle is fitted with a cable‑operated heater-tap mounted in the heater hose at the firewall. That means it isn’t a constant‑flow system, the tap regulates hot coolant into the heater core as the cabin temperature lever is moved.

The heater-tap’s job is straightforward: when the cabin control is set to HOT, the valve opens to let engine coolant flow through the heater core, providing warm air. Slide it back toward COLD and the tap closes, reducing or stopping flow to keep the cabin temp down. On the Gran Move, a small lever on the tap is moved by a cable from the dash, so correct cable travel and tap movement are key to getting proper heat.

As part of routine servicing, it’s smart to check the heater-tap whenever the cooling system is being inspected or the coolant is changed:

• Look for seepage around the tap body, hose barbs and clamps, any crusty residue or a sweet smell near the firewall is a giveaway.
• Move the cabin lever from COLD to HOT and confirm the tap lever travels fully to both stops without binding.
• Inspect the adjoining heater hoses for softness, cracking or swelling and replace them with quality hose if needed.

If replacement’s on the cards, use a quality OEM‑equivalent tap. Drain enough coolant to drop the level below the tap, mark the cable position, then swap the unit with fresh clamps. Refit the cable and adjust so the lever just reaches both mechanical stops at full HOT and full COLD. Refill with the correct coolant/inhibitor mix, set the control to HOT (tap open), run the engine to operating temperature, squeeze the upper hose to purge air, and top up the radiator and overflow. Recheck the level cold the next morning.

Typical failure signs on a Gran Move include stuck-on-cold heat (seized shut), permanently hot air (seized open), and small drips tracking down the firewall. There’s no fixed replacement interval, but many owners do the tap and heater hoses together during a major cooling-system refresh or when age-related leaks begin.

• Where is the heater-tap on a 2000 Daihatsu Gran Move?
  It’s in the engine bay at the firewall, in-line with one of the two heater hoses. You’ll see a small lever on the valve body with a cable attached that runs back through the firewall to the dash controls.
• What are the signs the heater-tap needs replacing?
  Little or no cabin heat with the control on HOT, permanently hot airflow, visible coolant weeping around the tap, a sweet smell near the firewall, or a stiff/binding temperature lever inside the cabin all point to a faulty tap.
• Can the heater-tap be bypassed temporarily?
  Yes, in a pinch the two heater hoses can be looped to keep the car mobile and stop a leak, but you’ll lose cabin heat and still need a proper repair. Make sure the coolant is topped up and the system bled after any hose changes.