I flushed my heater core

[S-FLY]

So, my XJ didn't really have the greatest heat and I read online that flushing the heater core may help.  While walking through Princess Auto this weekend looking at random parts,  I decided to tackle flushing the heater core. 

This is what I came up with:
- 7 feet of 3/4" ID hose $4.99
- 400 GPH 12 volt sump pump with 3/4" outlet $19.99
- Two 5/8" plastic barbed couplers $2.38
- Two 1" hose clamps $1.30
- Premixed coolant $10.99
- 4L water jug I had laying around
- Wash bucket


Hot water in wash bucket, with sump pump submerged and about 5 feet of hose going to hose that was connected to the water pump:


2 feet of hose connected to hose that was connected to the head, into the water jug:




Start up the pump, and flushed hot water through the core until the water going into the jug was clear:


Old coolant from the heater core:


Flushing hot water through the heater core and back into the wash bucket:


Reversed the hoses on the pump to reverse the flow of hot water through the heater core (I did this a few times to loosen and flush out garbage that was in the heater core):


The leftovers that was in the bucket from what the hot water flushed out:


The crap that came out of the heater core with the coolant into the water jug (will take to Canadian Tire for proper disposal):


Blow out the water from the heater core.  Hook everything back up the way it was and bleed the coolant system to get the air out.  Add premixed coolant as necessary.


So, all in all I think the flush was successful.   The heater seems to be working a bit better, but I have a feeling there's a lot more junk in the heater core, so what I may do is repeat the process and flush some hot water with CLR through the core and see what that takes out.  Anyways, I hope you guys find this interesting... if you don't have any heat, this might help. 

[TheCaptain]

Man great work on the play-by-play.

I was tackling my whole coolant system last week and was thinking about a way to flush the heater core without dismantling the whole works.  This way looks like an inovative way to cycle everything out.
I"m going to give this one a shot!

[Vinman]

Here's a kit you install in the heater hoses:

http://doitbest.com/Antifreeze+and+Antifreeze+Testers-Victor-model-V317-doitbest-sku-580813.dib

Canadian Tire sells similar kit for less than 10 bucks.

And you should use some coolant flushing chemicals to really see a benefit.

http://www.amazon.com/Technical-Chemical-Radiator-Flush-oz/dp/B0002JN2Z4

Vince

[S-FLY]

I actually had the whole coolant system flushed with chemicals at minute lube 2 weeks ago when I bought the jeep, which costed $160.  That dirt came from my heater core alone, which apparently the coolant flush didn't get.  I saw the kit at Canadian tire, also similar to the one at Princess Auto, but I don't have a hose, hence the pump. 

[hps4evr]

ummm, how bout un-hooking both heater hoses and sticking a water hose on the back end and back-flush the heater core. i guess try to catch all the ugly coolant. try to back flush it though, thats the key to getting the plug out. if you still dont have any heat. try a new t/stat and make sure your blend doors are working. those older XJ's had a funky valve some where between the fill bottle and heater hoses. i read a upgrade that you can do in JP mag not long ago. i think up dateing to the newer parts.

[S-FLY]

I think you're talking about the heater control valve from the pre-91 models.   I'd use a hose, but I didn't have one, also with a hose you'd only be able to flush cold water through the heater core, unless you hooked it up to a tap.