Before you begin:
* Safety First: Disconnect the negative battery terminal. This prevents accidental electrical shorts.
* Gather Tools: You'll need various tools including wrenches (metric), screwdrivers (Phillips and possibly flathead), pliers, a drain pan, rags, and possibly a coolant recovery system.
* Coolant: Have fresh coolant ready to refill the system after the repair. Consult your owner's manual for the correct type and mix ratio.
General Steps (Adapt to your specific vehicle):
1. Locate the Heater Valve: This is often found near the firewall, on the engine side, close to the heater core hoses. Your repair manual will show the precise location. It's usually a small valve with two hoses connected.
2. Drain Some Coolant: Before disconnecting any hoses, open the radiator drain valve to release some pressure and coolant. This minimizes the mess.
3. Disconnect the Hoses: Carefully disconnect the two hoses connected to the heater valve. Have your drain pan ready to catch the escaping coolant. It's helpful to mark the hoses to remember which goes where.
4. Disconnect the Valve: Once the hoses are disconnected, you'll need to remove the valve itself. This may involve removing clamps, bolts, or other fasteners. Again, your repair manual will guide you. Take pictures as you go to aid reassembly.
5. Install the New Valve: Install the new heater valve, ensuring it's properly seated and all fasteners are tightened securely.
6. Reconnect the Hoses: Reconnect the hoses, ensuring they are securely clamped. Double-check that you have them connected correctly (refer to your markings).
7. Refill the Cooling System: Carefully refill the cooling system with the correct coolant mix. Refer to your owner's manual for the correct capacity. Bleed the air from the system. This is crucial to prevent overheating. There are usually bleed screws on the engine and/or radiator. Consult your repair manual for the bleeding procedure.
8. Check for Leaks: Start the engine and let it run for a while. Carefully inspect all connections and the valve for any leaks.
9. Reconnect the Battery: Once everything checks out, reconnect the negative battery terminal.
Important Considerations:
* Repair Manual: This is absolutely critical. The above is a *general* guide. Without a specific repair manual for your 1995 Nissan Axxess (G20), you risk causing damage.
* Difficulty: Accessing the heater valve can be difficult due to limited space. Be prepared for some challenging maneuvering.
* Coolant: Coolant is toxic. Wear appropriate safety glasses and gloves. Properly dispose of used coolant according to local regulations.
If you are not comfortable working on your vehicle, it's best to take it to a qualified mechanic. Improper repair can lead to serious engine damage.
