Tuesday, September 20, 2011

What is the right way to change radiator coolant?

I drive a very old Mitsubishi Lancer. What are the right step to change the coolant? Should the engine be warmed up etc...



I need to know because the last time I changed the coolant myself, I did not know there was a drain plug under the radiator. So I unscrewed the top hose and let it out.



Few days later my water pump failed. I dont know if it failed because of what i did or not. (I've located the drain plug since then)



Coolant is due for change now and I hope the same problem does not occur again.
What is the right way to change radiator coolant?
I would make sure the car was cool before doing this. Hot coolant can easily scald you when being changed. Place a large container (large enough to hold on the coolant) under the drain plug. Open the drain plug and allow the coolant to drain out. Once the old coolant has drained entirely it might be a good idea to flush the system with distilled water. This isn't absolutely necessary, but its not a terrible idea. Once everything is sufficiently drained, close the drain plug, and begin to refill the system. Refill the radiator first until it is full, and then put some fluid into the coolant reservoir. Allow the engine to run for a brief time, then recheck the fluid in the radiator. More will probably need to be added. Repeat this process until the radiator remains topped off after being run. Be sure to check the reservoir as well to make sure it maintains enough coolant.
What is the right way to change radiator coolant?
Unscrew the bottom outlet hose on the radiator, or use the drain plug. Many radiators dont have a drain plug, so most people (myself included) just pull the hose.



Your water pump probably failed because the new coolant cleaned out all the junk that was holding the pump together, or the flush dislodged some junk from somewhere else in the engine and it got stuck in the water pump.



I seriously doubt that the water pump will fail twice in a row. Failing to flush the coolant on a regular basis has much more serious consequences, like a blown head gasket. Having a well-functioning coolant system also keeps NOx emissions down, since the engine doesn't get hot enough to create them.
you remove plug from bottom of radiator or bottom hose catch what you can casue its poison to pets and people ... you drain it either by letting it run with motor on or off best off but you can push out more old if you want with motor running a bit just dont let it over heat faster to remove bottom hose but more mess.. dont have to be warm and better if not since your hands will be in it some what
the water pump failure was coincidence. put a pan under the drain plug and let the antifreeze run out. refill it with green mixed 50/50 with water. warm the engine up until the thermostat opens and recheck the level in the overflow tank. some engines have a bleed screw you can loosen to let the trapped air out.
There is really no need to change it. If you must, just open the drain, with radiator cap off and when it's drained close valve and refill. Do not run the engine until coolant is replaced or it will damage water pump.
yes drain off water from radiator drain when its hot that will allow it to come from the engine as the thermostat will be open.then fill with required amount of A/F then fill with water .run for IO minutes then check again.

good luck h
The right way to change coolant is with a cooling system flush machine. Most shops can do the complete service for between 49-100 dollars depending where you live.