If you do the following, YOU ALONE are responsible for any possible damage that may occur to you and your automobile. I will not be held responsible for any damage of any kind. By using this post, you agree to this in full.
Here are the tools, parts and steps I used on my 2001 Mustang GT. Anything in blue is a link to the product. The prices are average.
Pliers that open wide enough to open hose clamps.
An empty used oil pan to collect old coolant.
10mm socket and socket wrench to remove thermostat housing bolts.
Flat head screwdriver.
PARTS from Walmart
1 Coolant Tester (the kind with the glass tube and 5 balls in it) $2
1 Prestone Flush 'N Fill Kit
2 bottles of Prestone Super Radiator Flush
14 Jugs of Distilled Water
3 Blue Jugs of full concentrate Super Tech Antifreeze/Coolant 5 year/150,000 miles
TOTAL PARTS COST will be around $60.
NOTE: The 2001 Mustang GT has a cooling system capacity of 14.1 quarts. 4 quarts = 1 gallon so 14.1 / 4 = 3.525 gallons.
1) With the engine cool, use the pliers to open the clamp on the lower radiator hose where it connects to the radiator and carefully slide the clamp up the hose.
2) Use the pliers to slide the clamp going to the hose on the coolant tank down the hose.
3) Remove the pressure cap from the coolant tank.
4) Place the oil pan under the radiator and carefully pull the lower radiator hose off.
5) As the coolant is draining, use the 10 mm wrench to remove the two bolts holding the thermostat housing on. Remove the thermostat from the housing, put the bolts back in and tighten them down.
6) You will see two black rubber hoses going into the firewall on the passenger side. These are the inlet and outlet hoses for the heater core. The inlet hose is very short, bends up and goes to the back top of the engine. The outlet hose is longer and runs behind the engine. Carefully cut the INLET hose that bends up and goes to the top of the engine. Install the two clamps and the largest back flushing tee in the kit on the hose you cut. Tighten the clamps using the flat head screwdriver.
7) Hook the included garden hose connector up to your garden hose that uses good quality city water. NEVER USE WELL OR SPRING WATER!!! Install the garden hose to the back flushing tee. Turn the water on.
8) You will see water and old coolant running out of the still removed lower radiator hose. When it runs clear, turn the water off.
9) Remove the oil pan you were using to collect coolant with as now you will be working with water which you can just let pour on the ground. The old coolant can be taken to a garage for proper disposal.
10) Carefully reattach the lower radiator hose to the radiator. Do not slide the clamp back to where it was as you will need to remove the lower radiator hose multiple times.
11) Turn the water back on. You will see it coming out of the still disconnected coolant tank hose.
12) Set your heater to blend, HIGH and full blast. Start the engine and let it run for about 10-15 minutes.
13) You will see water shooting out of the coolant tank hose. This is perfectly fine. Within 10-15 minutes, the water will become clear meaning any residual coolant or loose sediment in the cooling system is now gone. At this point, turn the engine off and the garden hose water off.
14) Remove the garden hose from the back flushing tee. Do not put the cap on the back flushing tee yet. This cap is on one of the smaller back flushing tees in the kit.
15) Remove the lower radiator hose. After the water drains out, reattach the hose.
16) Look at the inside of the coolant tank. If you see gunk in there, use the hose with the back flushing tee connector still on it to blast the gunk out of the tank. When it is clean and empty, you can reattach the hose but do not put the clamp back to where it was as the hose will need to be removed again.
17) Open the thermostat housing. Pour both bottles of Prestone Super Radiator Flush into the opening then place the thermostat back into the housing. Put the housing back together.
18) Start pouring in the distilled water. As you do this, you will see the still open back flushing tee gurgle and spit out water. This is air escaping the cooling system which is a good thing. When water comes out of the opening without gurgling and spitting, quickly place the cap on the opening and tighten it to close. Keep adding distilled water until the coolant tank is full. Leave the cap for the tank off.
19) Start the engine. You will notice the temperature gauge is COLD. Give it a little gas so you are at around 2000 RPM. When the gauge starts going up, get out of the car and check the hoses for leaks and make sure the coolant tank is still full of distilled water. Add more distilled water if needed.
20) Get back in the car and go back up to 2000 RPM. Do this until the temperature gauge reaches normal operating temperature. When it reaches this point, the coolant tank will start to empty since the thermostat is now opening. Refill it with distilled water and now place the cap back on it. Let the car run for 15-20 minutes. As it runs, keep an eye out for leaks. If you have a leak, turn the car off and see where it is coming from. More than likely, you will not have a leak.
21) Turn the engine off and let it cool until it is safe to touch the hoses. You will need to remove the hose from the coolant tank and the lower radiator hose. Also remove the coolant tank cap. As these are draining, open the thermostat housing, remove the thermostat, and reconnect the housing.
22) If there is gunk in the coolant tank, spray it out again.
23) Remove the cap from the back flushing tee and reconnect the garden hose. Turn the hose on. You will see dirty foamy water coming out of the still disconnected lower radiator hose. It will take a few minutes for the water to turn clear. When it does, turn the garden hose water off.
24) Reattach the lower radiator hose and the coolant tank hose. Leave the cap off the coolant tank.
25) Turn the garden hose back on. When water starts coming out of the top of the coolant tank, start the engine. You will see more dirty foamy water coming out of the coolant tank as the engine runs. It will take a few minutes until the water becomes and remains clear. This will be the point when you know all the Prestone Super Radiator Flush is now gone.
26) Turn the engine off then turn the garden hose off. When the hoses and engine are cooled down, remove the garden hose from the back flushing tee. Remove the coolant tank and lower radiator hoses and let the cooling system drain. As these drain, open the thermostat housing. Before placing the thermostat back in, rinse it off with distilled water. Close up the housing. This will be the last time you will have to mess with the thermostat.
27) If there is gunk in the coolant tank, spray it out with the garden hose. By now, it should look very clean. Take the connector off the hose, dry it off and put it in your glove box so you know where it is if you may ever need it again in the future. If you sell your car, the new owner will also appreciate having this.
28) Now we have to get all of the remaining city water out of the cooling system. This is very important for a number of reasons. Though safe for back flushing, city water contains chlorine, fluoride, and other chemicals which are safe for humans but not for long term cooling system use. These chemicals will also mess up the pH level of the cooling system to where you might create a corrosive acidic condition.
Most radiator repair shops and other places doing coolant changes use CITY/WELL/SPRING/DRINKING water because they DO NOT KNOW any better and/or DO NOT CARE about YOU or your cooling system!
This is why I do my own cooling system work.
29) Once drained, reattach the lower radiator and coolant tank hoses. Fill the coolant tank with distilled water. Once the back flushing tee finishes gurgling and spitting, put the cap back on it. Continue filling the coolant tank until it is full of distilled water. Leave the cap off the coolant tank.
30) Start the engine and bring it up to 2000 RPM. When the temperature gauge first starts to climb, get out of the car and check for leaks and make sure the coolant tank is full of distilled water. Get back in the car and bring the engine back up to 2000 RPM. When normal operating temperature is reached, get out of the car and add more distilled water to the coolant tank as needed. Put the cap back on it and let the car run for 15-20 minutes. This will let the distilled water circulate and collect the remaining city water in the cooling system. During this time, watch for leaks and make sure the car remains at operating temperature.
31) After 15-20 minutes, turn the engine off and wait for it to cool down. Remove the cap from the coolant tank and the coolant tank and lower radiator hoses. Remove the cap from the back flushing tee. Let the cooling system drain dry.
32) Repeat 29-31 at least two more times. If you still have at least two gallons or more of distilled water keep going, BUT SAVE 1 FULL JUG OF THE DISTILLED WATER. When you drain and the distilled water comes out clear, you have cleaned the cooling system and have removed all the city water. You cannot humanly get it any cleaner than this. If the distilled water is still coming out dirty, you either have an extremely dirty cooling system or a bad gasket leaking oil into the cooling system. You will have to take it to a trusted mechanic to get it fixed. In 20+ years of using the above steps in numerous different vehicles, this has never happened to me.
33) Take a shop towel and wet it with distilled water. Wipe off the lower radiator hose connector. Reattach the lower radiator hose and use the pliers to slide the clamp for it back in place. Do the same for the connector and hose going to the coolant tank.
34) Now all that is left in the cooling system is distilled water. Drained, this adds up to about 40% or more of distilled water left in the cooling system that cannot easily be drained out. Open up the concentrated coolant and pour it into the coolant tank. Replace the back flushing tee cap when distilled water comes out of it. Fill the coolant tank to the full line marked on the side of the tank. It should take about 1.75 jugs to fill it up. Put the cap back on the coolant tank. Start the engine and maintain 2000 RPM. As the temperature gauge rises, check the coolant tank. It will start to empty as the thermostat opens. WHEN IT IS EMPTY, you can carefully remove the cap and pour in more coolant. You should have used almost 2 jugs of coolant by now. Put the cap back on and sit in your car for about 10 minutes maintaining the 2000 RPM idle. The temperature gauge should remain at normal operating temperature. Turn the engine off. Check the side of the coolant tank to make sure it has coolant in it but do not remove the cap.
35) When the engine is cooled down, remove the cap off the coolant tank. It should be at the full line and look clean. A little cloudiness is OK. Use the coolant tester to check the freeze protection temperature. All four balls should easily float with the 5th ball slowly rising to the top with the other balls. You are protected to -40°F. If you actually live in a climate colder than that, you need an engine block and radiator heater.
That is pretty much it. The distilled water left in the cooling system mixed with the concentrated coolant you poured in using almost or all of the coolant in the two jugs will give you a ratio of around 60 coolant to 40 distilled water in the cooling system. THIS IS THE PERFECT RATIO! If you have a leak, get it fixed.
Now you will need to create some pre-mixed coolant using the third jug of coolant and the last jug full of distilled water. Pour 2 quarts of concentrated coolant into one of the empty coolant jugs. There will be 2 quarts left in the third coolant jug. You can use a flashlight pressed against the coolant jug to verify the levels if needed. Pour in about 1.5-1.7 gallons of distilled water into both jugs. Put the caps back on the and give them a good shake. These should now also have a ratio of about 60 coolant to 40 distilled water. Mark and date both jugs as pre-mixed and put them in a safe place. Use these to top off your cooling system as needed.
Use the coolant tester to verify the freezing temperature points of the coolant in your cooling system and in the jugs you made. They should all be the same.
To help avoid doing a full blown flush and fill again, get in the habit of removing the lower radiator hose once every two years, let it drain and refill with your pre-mixed coolant then make a fresh batch of pre-mixed coolant again using the directions above for topping off. Doing this will keep the additives in the coolant fresh thus protecting your cooling system and will help keep it clean.
IGNORE the coolant claims of 5 years / 150,000 miles.
Always check the coolant in the coolant tank at least twice a month to make sure it is clean and at the correct level.