You don't put water in your radiator, you put antifreeze.
On a 2000 Ford Ranger : With the engine cold the radiator should be filled to the seat for the radiator cap and the engine coolant reservoir should be filled to the cold mark
Radiator full and coolant recovery tank filled to mark Radiator full and coolant recovery tank filled to mark
No You don't Need to change the water pump But you should change it and the thermostat if radiator was full of sludge. if not then no to both.
Not necessarily! Let it cool down then check the radiator water level and the water overflow reservoir tank. In a properly operating system the reservoir adds water as needed to the radiator when it cools down after you quit driving. #1. The radiator should be full of water and the reservoir tank should be 3/4 full of water. #2. At a certain temperature or with the "AC on" the radiator fan(s) should be sucking air over the radiator and cooling coils. So! Fill the radiator and the reservoir and when it overheats in idle see if the fans behind the radiator are operating.
the overflow reservoir, it should have marks for full cold and hot
On older cars / trucks that do not have a coolant recovery tank you should fill the radiator to approximately one inch below the opening. ( when the engine is COLD } On more modern cars / trucks that have a coolant recovery tank, the radiator should be completely filled and the recovery tank should be filled to the full cold mark. You should only do this when the engine is cold to avoid personal injury. Why is the cooling system low? A pressure test should be performed and all leaks repaired.
Have you replaced the thermostat? The water in radiator should not be boiling! ------------------------------------------------------------------------------------------------------ Is your cooling fan/viscous clutch working ? (Helpfull)
3/4 full
If your 1997 Subaru Legacy is the same as My RS-B Twin Turbo?, the Radiator and Overflow bottle have to come out and the Thermostat is at the front of the Engine, down the bottom-just to the right of centre, (Thermostat is inside the bottom radiator hose), - My Thermostat just twisted/pulled out, let all old coolant flush out-put New Thermostat in its place, Radiator and Overflow bottle were put back in and radiator topped up with fresh coolant and water, Overflow was filled to second line as it should be, car was started with heater on full for 5 minutes to disperse any air in water - (note) after adding fresh coolant, add water in Radiator till it can't take anymore-to show its filled properly.
With the radiator full and the recovery tank 1/2 filled you will need to start the engine and when the temperature reaches 232 to 235 degrees the cooling fans should come on. If not then take it to a repair shop and have then diagnosis the problem.
The coolant light should be going out when the system is filled. The sensor itself or the float system is probably bad.
First make sure the radiator is full of coolant ;this is where the heat comes from. If it is full , then change your cars thermostat. The stat is located at the lower end of the top radiator hose within the water outlet. That should do it.