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mudslinger150 10-23-2009 08:55 AM

Pete and Repeat: revisit cooling system
I need a procedure on "How To flush Cooling system"

my issue is my heat is not blowing hot at all, take a long long time just to start throwing non-cool air.

Vaccume lines are connected

When i do flush how do i do it? with a hose?? and if im throwing water through the system, how do you get it back out (heater core) etc... to then put coolant in.

Ive looked all over for a Wrangler procedure and was unable to find anything


adkjoe 10-23-2009 09:20 AM

I flush it out with a garden hose for a while. There's going to be water left in there so what I do is fill it with mixed coolant run it for a day and then check it with a coolant gauge and either add straight coolant or water to make the ratio right. It's not cold enough yet to have to worry about having to much water in there but your going to want to check it a day or two after and top it off with straight coolant or water to make the ratio right. You can get a gauge at autozone for cheap.

mudslinger150 10-23-2009 09:32 AM

Joe, is it joe?

So i figured i would crack the bleeder and drain the radiator, then i would dissconnect the hose on the bottom of the radiator and use it as a catch/drain for my flush, so which hose should i use to blast water through up top??... one of the heater core hoses.

nicolas-eric 10-23-2009 09:34 AM

YouŽll need to remove the thermostat to flush the whole cooling system incl. the heater.

Jerry Bransford 10-23-2009 09:52 AM

Flushing the cooling system will not usually clear a clogged heater core. Disconnect the heater core's two hoses from where they attach near the front of the engine and repeatedly flush the heater core out via those two hoses with a garden hose. Reverse the direction of the flow through the heater core repeatedly until it flows fully in both directions, that should fix your heating issue. Then reconnect the two hoses back up (they are two different diameters so get the back on the right fitting) and fill the system back up with fresh coolant. Burp the cooling system of any remaining air afterwards and you're done.

mudslinger150 10-23-2009 10:07 AM

^beautiful, thank you, chances are i will flush just the heater core and then top it back off with coolant.


journeydog 10-23-2009 10:19 AM

Jerry described the deal pretty well. Prestone sells a rad. flush kit that once installed you leave permanently attached. It's pretty handy to use and helps when you do the backflush dance. Check your local auto store - the flush kit is under 10 bucks and makes life pretty easy.

CAUTION NOTE FROM DAD: If you drain the old stuff, please don't drain it out onto the ground. Supposedly, antifreeze mfgrs. have changed their formulas in recent years to eliminate the bad stuff, but who knows. Lotsa critters like birds like the sweet taste of antifreeze, so they slurp it up. If your dog drinks it, you can pretty well be sure that they will be upside down - dead - within a few days due to kidney failure. Not a nice way to die - supposedly very painful!:deadhorse:

mudslinger150 10-23-2009 11:19 AM

after i flush the JUST the heater core, should i fill the radiator back up with straight anti freeze or 50/50

nicolas-eric 10-23-2009 11:47 AM


Jerry Bransford 10-23-2009 12:06 PM

Yes, 50:50 but be sure to use only distilled water to mix with the coolant. Distilled water can be found in any grocery store for something like fifty cents per gallon. Mixing it with ordinary tap water will eventually clog the radiator due to its mineral content. Some coolants are already pre-mixed 50:50 so be careful not to mix more water with those.

nicolas-eric 10-23-2009 12:10 PM

In the summer use 75/25 because it cools better and in the winter 50/50.

Jerry Bransford 10-23-2009 12:12 PM

As in 75% water/25% coolant in the Summer. :)

mudslinger150 10-23-2009 12:20 PM

yeah ill just throw in some 50/50

nicolas-eric 10-23-2009 12:25 PM

And donŽt forget to make some pics and post them here when you do all that.

mudslinger150 10-23-2009 12:37 PM

haha yeah, i'll take pics this time

mudslinger150 10-23-2009 12:40 PM

what does the jeep hold 10.5 qrts or something like that... if im doing just the heater core i probably only need to buy one gallon to replenish...?

mudslinger150 10-23-2009 05:40 PM

Alright, so i flushed just my heater core and i got some nasty pea colored rust colored nastyness. I flushed one way then the other, until all that i was getting was a solid stream of clear water.

I then realized i should flush the rest of the system since the coolant was shot. I did so and filled her back up with some bright green goodness.

Heat is hot hot hot and really quick!

Thanks for all the help with suggestions

p.s. - this is posted in the other running (old) thread sorry

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