how to drain coolant?

[bigman5956]

does anyone know how to drain coolant on a 98 cavalier?

[Current Resident]

The drain plug is on the front of the radiator on the drivers side.

[Classicrocjunkie]

Ask and you shall recieve.. - I did a write up a year or so back and saved it for occasions like this.


First thing to consider is, do you have a way/place to dispose of the old
coolant? Storm drains, or pouring it into the ground is not only bad for
the environment but illegal. Including putting it in containers and throwing
it in the trash. Just thought I'd throw that out there, as many people
don't think about it ahead of time. If you don't have a way to dispose of
it properly, you should let a shop to the flush. Also, animals are actually
attracted to the sweet smell of antifreeze and will drink it if they can.
Unfortunately, it is also poisonous to them and most often they will die
(or at least get VERY sick) if they drink it. So be careful if you have pets.

With that said, though...at your local auto parts store, they will sell you a
small container of "cooling system flush". Most common is Prestone.
Pick up one of those and 2 gallons of Dex-Cool antifreeze.

Start with your car cool, or cold.

1) Loosen or remove the cap on the coolant reservoir
2) Completely drain the cooling system by either loosening the "petcock"
valve on the radiator or by removing the lower hose where it attaches to
the radiator. The valve is locate at the bottom, driver's side of the rad,
facing the engine. Most often it can be turned by hand, but sometimes
you may need a pair of pliers. Be careful not to damage the valve if using a tool.
3) When completely drained, leave the valve open and add 1/2 to 1 gallon
of water to the reservoir. You should then see the water exit through the valve.
4) Close the valve and again, add 1/2 to 1 gallon of water. Then pour in
the contents of the "flush" bottle. Continue to add water until the reservoir
is full or nearly full.
5) Start the car and let it run for approximately 10 minutes. Shut it off.
6) Let the engine cool a bit (10-15 minutes) then repeat steps 1 & 2.
7) Fill the system once again with water then repeat steps 5 & 6.
8) Repeat as many times as needed, until you see only clear water coming
out during the drain process.
9) With the drain valve closed, add 1 gallon of antifreeze, then 1 gallon of
water. Continue to add from the 2nd gallon of antifreeze until the coolant
level is at the "full" mark. You may or may not be able to get the entire
2nd gallon in there at this time. If it does take it all, continue to fill with water.
10) Repeat step 5
11) Add more water (or antifreeze if you didn't get the 2nd gallon in during step 9)
until it reaches the "full" mark once again.
12) Repeat step 5
13) If the coolant level went down again, repeat steps 11 & 5 until it is
full and stays full.
14) Check for leaks if you haven't already. If none found, you're done.

An alternative to this process is what's known as a "backflush".
This requires cutting one of the heater hoses and installing a flush tee.
There is a cap on the tee that allows a garden hose to be attached.
When the hose is turned on, it forces water through the cooling system.
The backflush is done in place of, or during, step 5. Most newer cars that
have had a well maintained cooling system do not require a backflush.
It is much more thorough flushing process, though, so something to consider.

Also, you might want to consider using distilled water on the final fill of the
system. Most often regular tap water is all that's used, but it does contain
some contaminants that can cause sediment and/or corrosion. Personally,
I consider this overkill, but it is recommended. Dex-Cool was created to
combat "hard water" scaling. Using distilled water is just extra insurance.
I would actually consider it more important to use distilled water with
regular (green) antifreeze but, again, most people don't. Most shops do
not use distilled water, either. Unless you plan on going 5 years or 100,000
miles before your next flush, I wouldn't worry about it.

I think that pretty much covers it. Give yourself a couple hours to do all of
the above with the heating up and cooling down process. You'll get better
results if you don't rush it. Have fun and enjoy.