Ram 5.7Hemi Coolant Flush DIY

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BadHemi2014

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First, thanks for the great write up!

But, I just had a total Oh **** moment.

Started to open petcock...
Turns pretty easy, so I feel good...
I see it kind of pop out but thanks to this thread I know that's ok...
Get a couple drops so I turn a little more, nothing happens...

Then it pops out completely!
And to make matters even worse, nothing's draining. And yes cap is off.
To cut to the good news, I was able to get it back in after a little seriously stressed out fiddling.
Bad news is now I know I have a lovely clogged up system.

(Truck had 118K miles and I'm sure this has never been done, had water pump replaced but wasn't flushed at the time)

Wish me luck, any advice appreciated as always.
 

roadrnnr

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There exists a sort of a vacuum pump that is able to suck the old coolant and then pour a new one in without creating air pockets/hotspots actually, e.g.: https://www.amazon.com/gp/product/B0002SRH5G but you need an air supply.

I think I am going to try one of these. Any body here use one? Looks to make this job a whole lot easier
 

Mister Luck

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This is a great thread
Hemi395
created with detail pictures and the only write-up pertaining to radiator maintenance and service that I could find with detailed information easily


Radiator Flush with a chemical descaler from the auto parts store would help neutralize calcium, rust, and mineral deposits some descalers are rated aluminum safe by the manufacturers.


In that case Distilled water is PH neutral and is only required for the cooling system refill.


The cooling system can be flushed with a water stream after the use of the chemical descaler because the residual chemical left behind in the system neutralizes the alkalinity of the tap water.


Tapered NPT engine plugs are best left alone and only removed for the worst case scenarios typically only used for engine block reconditioning prior to rebuilding and after machining.


A couple of people mentioned a cooling system pressure test kit for purging and testing the entire system including the heater core which is an excellent idea but you need to be careful of maintaining pressures bellow 7.5psi or as specified by the manufacturers instructions


The heater core components as well as gasket media materials pressure ratings should be carefully scrutinized when using a tester / purge tool.


Radiator Thermostat and Pressure cap should be tested and or replaced but not bellow OEM rated quality or temperature ratings


In the event of a thermostat failing to open at temperature the top hose can collapse and create a vacuum in the system.


To prevent this some parts manufacturers offer a “Fail Safe” thermostat that in the event of inoperability the thermostat fails in the open position but then still needs to be replaced because of the failure but prevents further damage to the cooling system .
 
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Mister Luck

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More digging through comparing service manuals to owners manuals I found the coolant capacity for the 5.7 engine radiator system is 16 liters with the reservoir being 2.3 liters making up the total coolant capacity to 18.3 liters

Other conspiring information starting with the 2016 RAM 1500 5.7 , 8 speed model year the 3 way valve was eliminated and in its place the two coolant hoses that were routed to the water pump directly are now attached through an extension sleeve into the lower radiator hose.
 

Doodoo972

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Yes, great post.
Thanks a lot for taking your time to share your experience with the community.
It will be a great help for occasional mechanics like me.

Great forum with great members !
 

JMBLOCKER

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Thanks for the great and informative post. It helped me a lot.
 

GARRY DE GUZMAN

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I have 2017 RAM 5.7 with 52K miles, should i just replace the radiator fluid and thermostat or do the complete flush?
 
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Hemi395

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I have 2017 RAM 5.7 with 52K miles, should i just replace the radiator fluid and thermostat or do the complete flush?
I would just do a radiator drain and fill with the Mopar 10 year OAT coolant. Are you having any issues with the tstat? Only reason I did a complete flush is because my 2013 has a build date of 12/12 and it looked like they put HOAT in my truck. I wanted to be sure it was completely flushed out.

Being a 2017 you definitely have the OAT coolant so all you would need to do is a rad drain and fill.
 

GARRY DE GUZMAN

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I would just do a radiator drain and fill with the Mopar 10 year OAT coolant. Are you having any issues with the tstat? Only reason I did a complete flush is because my 2013 has a build date of 12/12 and it looked like they put HOAT in my truck. I wanted to be sure it was completely flushed out.

Being a 2017 you definitely have the OAT coolant so all you would need to do is a rad drain and fill.
No issues with the tstat. Since, I will be keeping this truck for a long time, just trying to be on top of things and avoid issues and major\costly maintenance later.
 
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Hemi395

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No issues with the tstat. Since, I will be keeping this truck for a long time, just trying to be on top of things and avoid issues and major\costly maintenance later.
Definitely a good idea, you'll already have the coolant drained so no better time to change it....
 

MRFREEZE57

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Just did a coolant flush and change on my 2016 with 55k and replaced thermostat . not too difficult to do with exception of what the OP stated if anyone can figure out how to remove the block drain plug on the driver side, please tell how it can be done. I ended up draining the radiator and the R.H. block drain plug and removing the thermostat. did 4 flush and refill with distilled water until it came out mostly clear, then added 2 gal of the OAT coolant concentrate, the freezing point tests about -30 deg after a run to blend it good with the remaining water.
 
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Hemi395

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Just did a coolant flush and change on my 2016 with 55k and replaced thermostat . not too difficult to do with exception of what the OP stated if anyone can figure out how to remove the block drain plug on the driver side, please tell how it can be done. I ended up draining the radiator and the R.H. block drain plug and removing the thermostat. did 4 flush and refill with distilled water until it came out mostly clear, then added 2 gal of the OAT coolant concentrate, the freezing point tests about -30 deg after a run to blend it good with the remaining water.
You should be good with that for the winter. I would definitely check the freeze protection again after a few heat cycles just to make sure there weren't any pockets of pure water anywhere. I didn't have this problem, but I did check several times after the flush. Better safe than sorry.

I also checked it again in the spring and it was just under a 50/50 mix so I did another drain and fill of the radiator. I used a 75/25 of concentrated coolant to water and its been fine ever since.
 

MRFREEZE57

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You should be good with that for the winter. I would definitely check the freeze protection again after a few heat cycles just to make sure there weren't any pockets of pure water anywhere. I didn't have this problem, but I did check several times after the flush. Better safe than sorry.

I also checked it again in the spring and it was just under a 50/50 mix so I did another drain and fill of the radiator. I used a 75/25 of concentrated coolant to water and its been fine ever since.
Have ran it about 50 miles since the change, the left bank of the engine would likely be the only pocket of pure water. am going to test again. I guess the old Prestone tester is ok for this coolant as have found nothing that states if a special tester is needed for the Mopar coolant.
 
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Hemi395

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Have ran it about 50 miles since the change, the left bank of the engine would likely be the only pocket of pure water. am going to test again. I guess the old Prestone tester is ok for this coolant as have found nothing that states if a special tester is needed for the Mopar coolant.
Yup that's what I used, you should be good
 

MRFREEZE57

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Has anyone out there tested the Mopar OAT premixed? When I test it strait from the jug with the little prestone tester it shows around -20 freezing point. Am wondering if any hydrometer ****** accurate or a special one is needed?
 

HEMIMANN

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Has anyone out there tested the Mopar OAT premixed? When I test it strait from the jug with the little prestone tester it shows around -20 freezing point. Am wondering if any hydrometer ****** accurate or a special one is needed?

Wow that's not good. 50/50 EG / Water is supposed to be -35F (solidus / slush limit).

You're talking degrees Fahrenheit?

Imma gonna change mine next spring. Wondering how tough the block drain plugs are to get at. Also whether the t-stat needs pulling on this one, or if it has sufficient jiggle valves.
 

Frontbutz

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I haven't drained mine yet, but manual shows 18.3 qts total capacity, so if flushed with water several times and you can drain out at least 9 qts or more which would be half the system, then for the final fill with 9.15 qts concentrate (half the system) then the rest with water you should be at 50/50 mix. The only problem would be if you couldn't drain out at least 9 qts to make room for the concentrate then you would have to figure out how to get it back to 50/50.
 

Bighorn44

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Just had Firestone do a coolant flush and they put in a “universal coolant” the truck overheated 3 days later and when I opened the hood there was a sludge all over everything. Took it to the dealership and now The engine now needs to be re along with radiator and head gaskets and a few other things that will cost $16,000. Firestone is trying to deny responsibility because the coolant they used is “universal”. Anyone know how I could go about making the Firestone liable for the cost? Never had any problems with the truck prior to this situation.
 

Sasquatchtdg

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As someone that is about to tackle this list of parts:
Radiator - leaking, to be replaced with Cold Case
Thermostat - while i'm in there... Gates 195
Water pump - while i'm in there... Mopar pump
Serpentine belt - while i'm in there... Gates Fleet
Belt tensioner - while i'm in there... Gates
Upper Radiator hose - Gates
Lower Radiator hose - Mopar
4 Gals of 50/50 - Mopar
2 Gals of 100% - after reading through this thread, decided to get some just in case
2 bottles of Liqui-Moly radiator flush - 130k miles why not flush out crud to save new parts?

I am endlessly appreciative for this write up. A few questions:
Best coolant test method: refractometer, hydrometer, test strips?
Should I worry about the rubber components of the radiator mounting? the lower pin mounts or the bushing mounts? I need to order now and pray it arrives before the weekend.
Should I worry about reverse flow flushing to the heater core? How fragile is the heater core to water PSI? It only sees what the radiator cap relief spring is set at correct?
 
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Hemi395

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As someone that is about to tackle this list of parts:
Radiator - leaking, to be replaced with Cold Case
Thermostat - while i'm in there... Gates 195
Water pump - while i'm in there... Mopar pump
Serpentine belt - while i'm in there... Gates Fleet
Belt tensioner - while i'm in there... Gates
Upper Radiator hose - Gates
Lower Radiator hose - Mopar
4 Gals of 50/50 - Mopar
2 Gals of 100% - after reading through this thread, decided to get some just in case
2 bottles of Liqui-Moly radiator flush - 130k miles why not flush out crud to save new parts?

I am endlessly appreciative for this write up. A few questions:
Best coolant test method: refractometer, hydrometer, test strips?
Should I worry about the rubber components of the radiator mounting? the lower pin mounts or the bushing mounts? I need to order now and pray it arrives before the weekend.
Should I worry about reverse flow flushing to the heater core? How fragile is the heater core to water PSI? It only sees what the radiator cap relief spring is set at correct?
Thats a nice list of parts to change while you have the cooling system drained!

I used the hydrometer to make sure I had the proper 50/50 mix, seemed to work well. The test strips are more for testing the viability of old coolant.

The rubber mounts I personally would just order them and throw them in. Add it to the list of while youre in there parts.

Are you having any issues with the heater core? If not, I would just run some water through it both ways and then use 10psi or less compressed air to blow it out. JMO, since the dash has to come out to replace the heater core I wouldn't take a chance and put chemicals through it.

Also if youre going to use a flush, make sure you get ALL of it out of the block. You don't want any of the that to stay in the coolant after you're done flushing.
 
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