Using straight water in place of coolant will increase the chance of rust occuring within the cooling system and clogging up the radiator. Depending on the climate you live in, you will risk the possiblity of the engine freezing and cracking the block.
You can use almost any liquid in a radiator, but water is not the best choice. Water boils at 100 degrees (and your engine gets way hotter than that), also it freezes at zero degrees and in many places it gets colder than that.Engine Coolent is an additive that you add to water or replace the water in a radiator. Coolant raises the boiling temperature and lowers the freezing temperature so that your radiator will work in the widest possible circumstances.
Water should be fine, but mix it with coolant when you can to prevent rust from developing in the radiator.
I assume you want to change out the water pump and would like to know if you can do it without draining the radiator. You will lose approximately all the coolant in the radiator reservoir when you remove the radiator hose from the water pump. If the coolant is in good, clean condition, it might be wise to drain the radiator into a container and re-use the coolant.
The 1999 Wrangler is equipped with an overflow tank. The amount iof coolant to add to the radiator is slightly less than 2 gallons. Be sure to use either a 50/50 coolant (pre-mixed with water) or a gallon of concentrated coolant mixed with an equal amount of water. You will have about 3/4 inch of coolant left in the container when the radiator is full. The overflow tank is there to hold coolant when the radiator gets warm and needs to expell some of the coolant. So just fill the radiator with coolant. You'll know when it's full.
You don't, unless you are flushing the system. Use distilled water and add it to the coolant recovery bottle - and it needs to be mixed with coolant.
Assuming you mean "coolant" not water, if there isn't a drain valve on the radiator, remove the lower radiator hose and use a large/wide drain pan to collect the coolant.
To flush a radiator, first make sure the engine is off and cool. Locate the radiator drain plug, usually at the bottom, and use a container to catch the old coolant. Pour radiator flush solution and water into the radiator, run the engine for a few minutes, then drain the radiator by opening the drain plug. Finally, refill the radiator with the recommended coolant and water mixture.
Most, if not all, the coolant in the radiator reservoir will pour out when you pull the water pump. Drain the radiator and save the coolant (if you plan to re-use it) before removing the water pump.
Mineral sludge from tap water. A good radiator flushing will help and then use proper coolant to help keep the sludge building up and blocking the radiator.
To flush out the radiator of a Daewoo Matiz, start by ensuring the engine is cool and then remove the radiator cap. Place a drain pan under the radiator and open the drain valve to release old coolant. After draining, use a garden hose to fill the radiator with water, then run the engine for a few minutes to circulate the water. Finally, drain the water again and refill the radiator with fresh coolant to the appropriate level.
To fill the radiator coolant on a VW Vanagon, first ensure the engine is cool and remove the radiator cap. Use a funnel to pour the recommended coolant mixture (usually a 50/50 mix of antifreeze and distilled water) into the radiator until it reaches the fill line. Additionally, check the coolant reservoir and top it off if necessary. Finally, replace the radiator cap securely and run the engine to circulate the coolant, checking for any leaks.
The cooling system on this vehicle does not use a radiator cap on the radiator but on a remote tank. It may have a different (larger) cap on it than what you are used to seeing on the radiator.