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How to: Total Cooling System Flush & air bleed�!

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#1 · (Edited)
How to: Total Cooling System Flush & air bleed…!

The time arrived to once again flush the old coolant from the engine and radiator. I really struggled with this process the last time (and sure I did not do it right :slap:) which resulted in an extensive searching for a definitive “how to” on CF, LX, internet, and several conversations with Brian at BND automotive. After gathering all the information together, I still struggled with how to really guarantee a complete fluid flush and most importantly, how to ensure all the air was bleed out from the engine. I ended up piecing together a method that truly worked and is simple. I also feel compelled to pass this information along to you my fellow LX’rs. Below is a very detailed step-by-step course of action.

I would suggest using the "show printable Version" under thread tools before printing this out...!

What you will need:


  • Approximately 3 hours time
  • 7mm and 10mm sockets – to remove under engine dirt guards
  • 13mm socket – to remove water pump bolts
  • Small crescent wrench – to turn radiator drain valve
  • Pliers – to pull drain valve out (just enough to allow coolant to flow out – not to remove valve)
  • 1/4 Allen wrench – for air plug on water pump
  • Brake bleeder repair kit (this proved to be magic – more detail below)
  • Plumbers tape – For bleeder threads
  • Gasket material – 4 x 4 inch piece to make temporary gasket between water pump and radiator hose
  • Container – half gallon or so to capture coolant coming from water pump air bleed plug
  • 3 feet of 5/32 I.D. rubber vacuum line
  • Pan x 2 – to drain old coolant into for disposal
  • Coolant bottle Funnel – to fill overflow reservoir without spilling coolant in engine bay (this also proved to be magical, more detail below). I used “Lisle 24610 Spill-Free Funnel” from www.Amazon.com
  • Deionized water – I used 10 gallons, get from your nearest grocery store, it is inexpensive
  • Radiator flush chemical of choice – to remove any internal built up scum
  • Radiator coolant of choice – must be chemically compatible with Dodge/Chrysler factory coolant (H.O.A.T. – Hybrid Organic Additive Technology) see web page below for more detail: http://www.chargerforums.com/forums/showthread.php?t=179673

Preparation steps I took

Edit: 2nd thoughts about disposal of old coolant. You need to read below an find out which best fits your particular situation for the common good of all...!
1. Do not discard in gutter because bad things happen.
A. Animals may drink it as it is sweet to the tongue and it will kill them.
B. Any rust in coolant will stain the driveway and gutter.
2. If you are on a government sewer system, call them and ask if it "OK" to add coolant to the system via the toilet or other drain. Some systems may be able to handle it and others may not. If you do not know if you are on one that can take coolant, give them a call and find out. In my situation, I am connected to a major city sewer system and admit I did have a fleeting thought about dumping it down the toilet and as I was already into the project is did do this. In retrospect, I should have done my homework and made a couple of phone calls or at least checked my local sewer systems do's and don'ts on the internet rather than make an assumption it would be OK...

3. Do not dump coolant into a septic tank system. It will kill off the useful bacteria that is needed to break down normal sewage.

4. Most likely the overall best solution is to collect the used coolant and turn it in on your local HAZWASTE turn in days.

5. Here is a interesting thread found by GLHS837
http://www.bobistheoilguy.com/forums...=629269&page=2
In this thread, two posters in particular, one a sewer system operator of some kind, one a water resources engineer talk about proper methods and conditions of coolant disposal...
1. Start with a cold engine.

2. Lift front end of vehicle and place on jack stands to prevent an accidental drop when you under the car. I’m a trauma x-ray tech and have witnessed this happen… it hurts just a bit…!

3. Remove both under engine dirt guards to gain access to the radiator drain valve. Don’t forget there are 3 plugs to remove inside each front wheel well.

4. Place pan to catch coolant under drain valve – located on the passenger side at bottom of radiator.

5. Remove pressure cap from overflow reservoir on driver side of car just behind air intake assembly. This will prevent an air lock or vacuum being created as radiator/engine block drains

6. Open Radiator drain valve to drain old coolant out
a. Using a small crescent wrench turn the drain valve 90 degrees counter-clockwise to open the valve.
b. Important: If the valve does not “pop out” about 1/4 inch when rotating, then use a pliers to pull / wiggle it out to get coolant flow to start.
c. Valve looks like this:


Picture provided from internet for “what it looks like only – do not remove valve from radiator.

7. As pan fills, have a 2nd pan ready to go. When just over half filled, slide the 2nd pan into place and dispose of the old coolant in an approved method for your particular situation.

8. Once radiator is empty, close the drain plug by pushing in and turning “clockwise” 90 degrees.

9. Remove the thermostat. This step will allow continual flow of cleaner and deionized water through radiator and engine block. This I believe is beneficial when using the radiator cleaner flush chemical AND for performing a complete flush of the engine.
I choose to not go after the engine block plugs as that would have resulted in much more work. I also reasoned that if I ran enough deionized water through the cooling system, any cleaner left over would be so dilute is would no longer matter.
10. With thermostat removed, fabricate a temporary gasket to create a water tight seal



11. Reinstall radiator hose to the water pump for the clean / flush phase.

12. Remove the water pump plug and replace with brake bleeder repair kit.
This plug is located on the front of the water pump near the top. This plug must be loosened to bleed air out of the motor during the fill.

Problem: When loosening to bleed air out, coolant would also come out and drip onto front of engine and serpentine belt – not good in my opinion. Also, the Dodge / Chrysler manual calls for a bleed fitting to replace the plug to properly bleed air out the engine during fill (see manual instructions below).

What to do? As I was looking for a bleed fitting at the local auto parts store and saw a “Brake Bleeder Repair Kit” and thought; this fitting may work just like it does when bleeding air out of brake calipers and pipe thread is pipe thread... it worked out perfectly…!


13. Remove the water pump bleed plug with an appropriate Allen wrench and make sure it is a perfect fit. I had to use a 1/4” Allen socket because the factory had it gorilla tight.



14. Install the base of the bleeder using plumbers tape. It threaded in almost to the hub before getting tight. Then screw in the “Banjo” bleed fitting. Tighten the banjo fitting to finger tight and attach the 3 feet of vacuum line.



15. Route the vacuum line into a 1/2 gal container and place on top of radiator



16. Prep the overflow tank
Using the correct combination of pieces supplied, place the “Coolant bottle Funnel” onto the top of the overflow tank.


This funnel works like a charm and flushing / filling coolant system is a snap and is drip free…!


Clean and flush the engine block of old coolant
1. Recheck radiator drain plug to make sure it is closed.

2. Pour radiator cleaner / flush chemical into the funnel.

3. Add deionized water into funnel until funnel is about half full.

4. Start engine and let idle.

5. Turn the cabin air heater on full heat. No need to run the fan. The idea here is to make sure water is flowing through the heater coils. This will flush the coils and also help to prevent an air lock within the coils.

6. Keep adding water until coolant system is full.

8. Loosen banjo bleed fitting about two full turns so air can escape. Once air is out any sputtering will stop and a solid stream of fluid will be flowing out. Then rotate tubing to close banjo fitting until just seated.

9. Let it run for 20 minutes or so. I also revived the engine intermittently to about 2,000 rpm and held it there for about a minute make sure the water was flowing through the engine block/
FYI: with the t-stat out, engine heat reached a max of 160 degrees on the EVIC in 90 degree weather.
Now is a good time for a beer!
Empty / exchange radiator and block water with deionized water
1. Now it starts getting a little busy, almost need 2 people at this point; one to add water into funnel and one emptying drain pans.

2. Leave engine running at idle.

3. Open the radiator drain valve and watch the dirty water pour into pan.

4. Loosen banjo bleed fitting about two full turns until water is dripping into top side container.

5. Keep adding deionized water and emptying drain pans until the water coming out of the drain plug is near clear.

As the 5.7 Hemi coolant system holds 13 quarts (6.1 holds 14 quarts) I decided to run about 5 gallons (20 quarts) through to make sure the deionized water exchange was damn near complete and only fresh deionized water was in the system.
6. Now turn off the engine and let the radiator continue to drain out until water stops flowing.

7. Wait for engine to cool down a little even though it only reached about 160 degrees
Good time for another beer!
Add coolant back into cooling system
1.Close radiator drain valve

2.Unbolt radiator hose from water pump and reinstall t-stat.
IMPORTANT: Make sure the little air weep hole on the t-stat is “up” at the 12 o’clock position
I also choose to put a very thin film of grease on the rubber gasket to make sure it ‘slid’ easily into the correct position without buckling or anything else weird happening
3. Close banjo bleed fitting until just seated

4. Add appropriate amount of coolant into funnel
IMPORTANT: If coolant direction calls for a 50/50 mix, remember you started out with a system that holds 13 quarts for a 5.7 Hemi or 14 quarts for a 6.1+ Hemi, but is now partially drained.
What remains in the system should be near pure deionized water.
Doing the math… to end up with a 50/50 mix, you must add 6.5 undiluted quarts of coolant for a 5.7 (7 quarts for a 6.1) then continue to fill with water until system is full. The final mix in the system will now be 50/50.
5. Now add water until funnel is about 1/2 full.

6. Restart the engine and let it start warming up.

7. Make sure cabin heater is on full heat to ensure coolant is flowing through the heater coils and hose. Again, the fan motor can be left in the low position.

8. Add water as the engine pulls fluid from funnel into coolant system

9. When engine is warm and t-stat opens. You will know as top radiator hose will become very warm if not hot to the touch.

10. Open the banjo fitting and let air escape.

11. Rev engine up to 2.5K rpms a few times for about 15 seconds or so to make sure the fluid is moving through the system and any air is migrating up and out the banjo fitting / hose into the container sitting on top of the radiator.

12. Once air is purged, a slow steady stream of coolant mix should be flowing out of the banjo fitting / vacuum hose into the container.

13. Rotate hose to close banjo fitting. Then remove vacuum hose and tighten banjo fitting, but don’t over stress it.

14. Shut off engine and let it cool down, this will actually pull more water into the coolant system from funnel.

15. Once cool, twist T-handle fitting into funnel and remove funnel.



16. Install pressure cap on overflow reservoir

17. Reinstall dust guards under engine bay

18. Clean up your stuff and have another beer!

Recheck your fluid level
1. After driving for a day, recheck your fluid level in the morning when engine is stone cold. Fill as needed to between the min / max marks on the over flow reservoir.

2. If it happens to be your day off, of course, have another beer!

:beerchug:
 
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#2 ·
Great Job, Jed....Gotta do this and get my Qb coolant in w/ Moroso tank....thanks a bunch.
 
#3 ·
Hmmmm, not sure about the toilet thing. Old coolant should be turned in on your local HAZWASTE turn in days.

Okay, so rather than just say that, I actually did a little research.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=629269&page=2

Interesting thread, two posters in particular, one a sewer system operator of some kind, one a water resources engineeer.

My takeaway? Dont ever put it in your toilet if you are on a septic system, like both of my houses are. It will cause harm to the bacteria in the septic tank and you need that bacteria to make the system work.

If you are on a government sewer system, call them and ask. Some systems can handle it and are just fine with, some systems are not. Here in my neck of the woods, a semi-rural county, there are maybe 4-6 smaller sewer systems operated by the county, and I wold have no way of knowing the level of technology for any given house that is hooked to the system.

If you do not know if you are on one, call your local system, they can tell you if you are or not:)
 
#6 · (Edited)
Hmmmm, not sure about the toilet thing. Old coolant should be turned in on your local HAZWASTE turn in days.

Okay, so rather than just say that, I actually did a little research.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=629269&page=2

Interesting thread, two posters in particular, one a sewer system operator of some kind, one a water resources engineeer.

My takeaway? Dont ever put it in your toilet if you are on a septic system, like both of my houses are. It will cause harm to the bacteria in the septic tank and you need that bacteria to make the system work.

If you are on a government sewer system, call them and ask. Some systems can handle it and are just fine with, some systems are not. Here in my neck of the woods, a semi-rural county, there are maybe 4-6 smaller sewer systems operated by the county, and I wold have no way of knowing the level of technology for any given house that is hooked to the system.

If you do not know if you are on one, call your local system, they can tell you if you are or not:)
You have raised some very good points for consideration! One should definitely check this out for the common good of all...! In my situation, I am connected to a major city sewer system in San Diego and admit I did have a fleeting thought about it. In retrospect, I should have called or looked up info rather than assume it would be OK...

To reiterate: This thread is a good read before choosing where to dump used coolant...
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=629269&page=2
 
#4 ·
Nice write up Jed!!! I had already a couple beers when you explained this procedure to me at Allen's house... lol
 
#9 ·
Nice writeup, big detail, good pics. This looks a whole lot like work!:cursin:

Last flush I did I used this:

http://www.acehardware.com/product/index.jsp?productId=1289874

What's the difference between distilled and deionized water? I've always used distilled for batteries and cooling system top-offs.

Also, in the fill part, I didn't see you using distilled water for the final fill, maybe I missed something.

I'd take the old juice to the local dump for hazmat disposal. Sewer systems have enough **** literally to deal with. And as GLHS notes, NEVER dump this stuff into a septic system.
 
#12 ·
All them Navy years:) First base I was stationed at, NAS Moffett Field, had been a base since the 30s, airships at first. I was there 84-90. About 89, they started using some funky ground penetrating radar around the base on a cart. ASked them what was up. Seems that there were seven old wells on the farms the base was made from. Over the next 50 years (stopped in the 70s) the Navy folks used them as HAZMAT drains, dumping untold thousands of gallons of old hydraulic fluid, fuel, who knows what. By the 80s, they had been sealed of for over a decade, and nobody knew where they were....... they were trying to find them.

I'm not Captain Planet, but I do keep an eye out:)
 
#14 ·
Ha, your "little tip" is actually a huge tip! I totally forgot to add the heater should be on full heat to prevent the heater coil air lock. Will add now...Thanks Hemi31 :rocker:
 
#15 ·
Jed- Nice write up. I have the Lisle Funnel, and am getting ready to flush and install my Killer Glass (finally). As far as disposal of coolant- in California we hae new "Urban Runnoff" laws. (NPDES) Legally- you can put NOTHING in the sewer system. Fines are rough. Do Not drain and wash down into street. I would suggest taking to Hazardous waste collection facility. San Diego Water Quality Board is probably the strictist in the state, and probably the country. So bottom line... Dont do "Old School" like we grew up with, and wash it down into the gutter. I was on a City Council when these laws were inacted, and they are quite overboard, (in my opinion).
 
#19 ·
So I got all of the necessary supplies to do this and followed the instructions exactly as described. Everything was going great up until the part about leaving the engine at idle, drain the system and pour in clean water until is starts coming out clear. Every time I opened the petcock while the engine was running, the coolant/water would start to boil in the reservoir and then explode all over the place. What was I doing wrong???
 
#20 ·
Did you remove the T-stat? With the T-stat out, the engine and coolant/water should not get hot enough to boil.
 
#22 · (Edited)
Just to add to this, I'm currently waiting on a buddy to bring me a Size 11 Hex key. Not sure when they made the change bit at least on 2015 SRT's it's no longer a 1/4 Hex :(

Nvm, I found out they changed that between the 5.7/6.1 and 6.4 lol. However I did have the added bonus of having the drain plug pop off, from the pressure so that's fun. Guess I'll be by for a trip to the Parts dept. Tomorrow morning :(
 
#25 ·
This is a great forum post.
I did a radiator flush and I don't believe I bled the system properly.
This led to slight overheating and now a busted radiator.

Would be great to get the pictures for this post as I can't view them.
Would love to have the bleeder process pics.
I am going to replace the radiator once the part comes and want to bleed and fill the system properly post install.

I followed all the steps EXCEPT the bleeding process above. Now I see the error and cost of my ways.
 
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