Coolant change/flush-proper procedures

boomer18boomer18 Member Posts: 24
I've heard that pouring room temperature fluid on
a hot radiator core/hot engine block can warp
it/them. If so, what is the proper procedure to
flush and change fluid? Most people drive their
vehicle in for service and the motor/radiator is at
operating temperature---should the vehicle be
allowed to cool down completely before this service
is performed? For example, left there overnight
before service is performed? Does it depend on
your engine block/head/and radiator core
material(s)? I usually drain my coolant (cold
motor)every 2 years, removing block plugs when
available/accessible, add 50-50 fresh coolant and
distilled water. I'm afraid to "flush" the system,
unless I use a milder product, such as the ones
that say you can leave them in for 100 mi. (and
even then I have: let system cool completely,
drain, add pure distilled water, warm to operating
temp., let cool completely, add new coolant mix).
Also, I collect in labelled containers-not mixing
different maintenence fluids-all drainage
practicable, and take to hazardous waste
collection/roundup. 'Guess it's important to wipe
up as much of spills as possible, too, so that
critters, human and otherwise, are not poisoned.


  • boomer18boomer18 Member Posts: 24
    Sorry, I omitted the "drain" step in my prior post about my flush procedure. (drain the distilled water after warming system to operating temp, and before adding new coolant mix, of course!)
  • boomer18boomer18 Member Posts: 24
    I should have posted that I drain the distilled water "rinsing" water after cooling the system completely and before adding new coolant mix.
  • pat455pat455 Member Posts: 603
    As I just posted to you in the other topic you created, it is always a good idea to look for a relevant topic into which your questions will fit.

    For this question, we already have this topic:

    Coolant (Topic #1656)

    There are very few posts there, but it is a great place to ask your question. You can copy it from here and then paste it into that topic (although you'll have to do some cleaning up of the spacing).

    Good luck, and welcome to Town Hall.

    Community Leader/Maintenance & Repair Conference
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