Ram 5.7Hemi Coolant Flush DIY

[Sasquatchtdg]

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.

Well this whole ordeal turned into a fiasco. I should probably have the system flushed again since I'm sure I did not properly flush the system. The radiator replacement took way longer than expected. The wife was pissed over how long it took. Called in reinforcements which was helpful.

Long story short, I hope I haven't completely buggered my truck cooling system.

 

[Xsen]

I'm thinking of doing a full system flush soon, as I strongly suspect the coolant quality to be questionable to say the least. Anyway, what I have in mind is:
1. Make an improvised flushing machine, basically an electric powered water pump, some piping and a few taps, some hoses to connect it to the cooling system. Ideally add some reservoir with a heating element in it, as hot water with some flushing agent works real good. I want this thing to be able to switch the flow direction between the two ports so I could do both reverse and normal flow flushing. Seen a similar device in one of the local shops, they use it to flush the heater cores. Crude, but it really gets the job done.
2. Drain the system from the rad and the heater core, leave the block plugs alone.
3. Remove the T-stat
4. Flush the radiator, the block and the heater core separately from each other. Heater core is easy enough, the radiator too. I'm a bit worried about the block, but theoretically - having the flow generated by an external pump via the top and bottom hoses is sort of the same as having the engine water pump running.
5. Get as much water out of each of the components as possible.
6. Reconnect everything, refill and burp the system.

This in my opinion should get most of the debris out of the system. Any opinions on further improving this plan?

 

[Daniel12]

Going to attempt this flush on my 2017 Sport. After flushing a few times with distilled water until clear, should I use compressed air to blow the remaining water out of the system before adding the coolant? I know the heater core can be blown out with a low pressure around 12PSI, but is there any risk of damaging other components if I go to blow out the rad or engine block?

Was thinking I could put this coolant cap on, attach my 15gal compressor to it and blow out the whole system with the heater core disconnected. I'd blow out the heater core separately at a lower pressure, then refill.



Thanks

 

[Hemi395]

Its worth a shot, just make sure the pressure doesn't exceed 16psi which is what the radiator cap is.

Let us know how it goes!

 

[Hemi395]

I'm thinking of doing a full system flush soon, as I strongly suspect the coolant quality to be questionable to say the least. Anyway, what I have in mind is:
1. Make an improvised flushing machine, basically an electric powered water pump, some piping and a few taps, some hoses to connect it to the cooling system. Ideally add some reservoir with a heating element in it, as hot water with some flushing agent works real good. I want this thing to be able to switch the flow direction between the two ports so I could do both reverse and normal flow flushing. Seen a similar device in one of the local shops, they use it to flush the heater cores. Crude, but it really gets the job done.
2. Drain the system from the rad and the heater core, leave the block plugs alone.
3. Remove the T-stat
4. Flush the radiator, the block and the heater core separately from each other. Heater core is easy enough, the radiator too. I'm a bit worried about the block, but theoretically - having the flow generated by an external pump via the top and bottom hoses is sort of the same as having the engine water pump running.
5. Get as much water out of each of the components as possible.
6. Reconnect everything, refill and burp the system.

This in my opinion should get most of the debris out of the system. Any opinions on further improving this plan?

That looks like a good plan! Just make sure you don't build up too much pressure in any of the components and you should be good.

 

[EriikK]

Silly me, I read and trusted what was written on the bottle. :-(
Specifically, last year when I installed the engine in my 2015 6.4 2500, I used the OAT coolant as recommended in the manual. All was well. But then I was chasing a minor leak while on a long trip and I topped off with Prestone "for all vehicles". It even specifically says on the back it is compatible with OAT so I thought it should be OK. Shortly after, my heater stopped working. Now I have the cooling system apart for other reasons (cam and lifters) and I am finding red mud everywhere in the cooling system.
So I'm flushing and cleaning everything and replacing the radiator for good luck since it is old anyway and I tow a lot.

So here is the question. Since I'm starting from fresh, should I use Mopar OAT or should I use something else that I can get at a parts store if I have a leak when I'm out of town?

Nobody else ever works on my vehicles so that's not an issue.
Is OAT better than other choices, or is it "anything is OK, just don't mix"?

 

[HEMIMANN]

I believe OAT is longer lasting additives than HOAT or Inorganic, is the deal, an OEM's have an interest in protecting themselves from customers that don't maintain properly so they don't end up in court cases.

The deionized water does the cooling, and to a lesser extent the ethylene glycol

The additives are there to reduce corrosion and lubricate the water pump bearing. In diesels they also have SCA as a wet cylinder surfactant to prevent cavitation erosion.

 

[Hemi395]

Honestly the Mopar OAT is pretty good coolant, I would just go back with that. My truck is 11 years old now and has only has the Mopar OAT. Anytime I've had to open the cooling system for any reason, it is virtually spotless. Plus with the concentrate you can dial in your mixture for your climate.

 

[EriikK]

I took your advice and got the Mopar purple OAT stuff. I'll carry a jug in the truck on trips. And if I need more, Ram dealers are not exactly hard to find.

 

[Hemi395]

I took your advice and got the Mopar purple OAT stuff. I'll carry a jug in the truck on trips. And if I need more, Ram dealers are not exactly hard to find.

Awesome! Yeah the Mopar coolant is one of Mopars better fluids.

Thats exactly what I do, I have a tote in the bed with the Mopar OAT, some oil, some trans fluid, and brake fluid.

 

[EdGs]

Awesome! Yeah the Mopar coolant is one of Mopars better fluids.

Thats exactly what I do, I have a tote in the bed with the Mopar OAT, some oil, some trans fluid, and brake fluid.

Same here, I keep a tote with fluids, tools, jumper cables, etc. on my redneck bed slide when I go on trips.

 

[ddttm]

Meh... I may pass on it then since the drivers side drain plug is difficult.

Yes, I'm a ******* and wasn't paying attention when I went to put more washer fluid in lol.

I did the same thing...

 

[Xsen]

So in case anyone wondered what 10 yrs would do to the factory coolant - I have an answer. Finally got around to flushing the system, what came out is in the rightmost bottles:


Funny thing - this, erm, liquid still worked, my temperatures never got out of control.

I used a chemical cooling system cleaner twice - with the first and third water fills and then kept on flushing everything out. Eventually I got tired of the drain fill routine and disconnected the supply hose that feeds the cabin heater and the transmission heat exchanger.



The hose on the left drains into a bucket, the hose on the right is brought up and has a funnel attached to it. To flush the small circuit the I'd fill the funnel with water slowly until it starts dripping into the bucket then start the cold engine and really pour the water into the funnel until the bucket was full. The water would go into the heaters, circulate back to the block, go through the block and pour out. You can easily verify this by sensing the temperature of the water in the bucket - it's going to be warmer than what you put into the funnel.

This proved to be very quick and efficient, the bottles on the left contain what came out on my last flush.


Before reassembling everything, I've separated the heater supply from the 3-way valve, connected the hoses to supply and return and did a reverse flush with compressed air a few times. Then I took the water pump off (not part of the flushing, but it was about to die anyway), blew the air into the ports on the block and reassembled everything.

I was going to use an external electric pump to do the flushing, but this method proved to be way easier and faster than putting together all the fittings and hoses needed to connect the pump.

 

[Bill Clune]

Well just to make everyone's head explode, ill tell you what i have been doing for 40+ years, without issue on hundreds of vehicles.

1. I drain the system, add CLR or "Evaporust" and topped it off with a garden hose.
2. if using CLR I then drove if for an hour, if evaporust i drive it for a WEEK, just read the label.
3. let it cool and i drain the system again from the petcock also remove the thermostat, reinstall the housing.
4. remove the upper radiator hose and put the garden hose in the radiator fill cap hole.
5. with the hose on, idle the engine until the water runs clean usually only a minute or two.
6. disconnect the heater core hoses and back flush in both direction with a garden hose.
7. pull the lower radiator hose, this gets a lot of water from the motor as well as the radiator.
8. I might pull the drain plug from the side of the block, i say might because if you cant, you cant!
9. install a NEW thermostat, renistall the hoses and fill it up with correct fluid 50/50

using distilled water is a total waste of money as you are going to remove 98% of the offending water and related minerals when you pull the plugs!
Using a radiator test make sure you have the proper coolant water ratio.

 

[PaleFlyer]

My '18 1500 Rebel Hemi factory fill is Orange, not Purple... Checked it when I did the Rear Diff, after doing the tranny...

 

[Wild one]

My '18 1500 Rebel Hemi factory fill is Orange, not Purple... Checked it when I did the Rear Diff, after doing the tranny...

It changes colour after awhile . It started life as purple though

 

[PaleFlyer]

It changes color after awhile . It started life as purple though

Guess that needs to get added to the list then... Knew I needed to do something soonish, as the reserve tank looks to be basically dry (after 106k), but... Didn't know the fluid was also toasted...

 

[larrymax]

I learned a lot today about how coolant works. First time ever working on it. I got a p0128 code a few weeks ago and through many google searches figured it was the thermostat. 2014 2500 6.4 with 103k. That must be it and the coolant needed to be changed anyways. Why not. As far as what the truck said, my temps were never over 220.

After figuring out I would not be able to do this without removing the fan shroud, I spent the better part of an hour trying to get it out. I finally said to hell with it and broke it at the bottom. The upper part remained in tact and was re-installed. The lower part will go in the trash and I couldn't care less. Maybe I'll learn another lesson in the future?

Draining the whole 2 gallons out of the radiator and replacing the thermostat was pretty easy. Now I became concerned with the air that was in there and spent the next 3 hours making an EPA disaster zone in my garage and wasting about a half a gallon of coolant on the floor before I realized the obvious.

Start the truck and wait for it to get to temp. Sure enough it sucked the coolant in and I refilled it as it went. Waited more, and watched it rise...Sqeezing the upper hose over and over to get the air out. Oh, it's not stopping. Shut it off but it was too late. Spilling everywhere. Again, oh that's just air coming out. I'm winning...

After the 3rd time of watching this happen I finally realized the obvious. The air is out, you're boiling the coolant and it's going to go somewhere moron.

I made this a bigger deal than it had to because I was so concerned about the air in the system and I have no idea what I'm doing. Once I decided to put the cap on, things went much better because I realized pressure reduces boiling temp. I still have no idea if the thermostat was bad, but it's got a new one and new coolant...many times over. Cleared the code, but the light remains.

I hope the engine check light goes away. I also found out, an all of a sudden throttle position sensor code is directly related to coolant while I was doing this. That one cleared WTF

I'm going to change the transmission fluid tommow. (yes I bought the metal nut to replace the plastic one for the filter) Wish me luck

Edit: I just realized this was a 5.7 thread. I can't delete/move it. Sorry about that. If it helps, I'd have done the same thing to a 5.7

 

[Hemi395]

I learned a lot today about how coolant works. First time ever working on it. I got a p0128 code a few weeks ago and through many google searches figured it was the thermostat. 2014 2500 6.4 with 103k. That must be it and the coolant needed to be changed anyways. Why not. As far as what the truck said, my temps were never over 220.

After figuring out I would not be able to do this without removing the fan shroud, I spent the better part of an hour trying to get it out. I finally said to hell with it and broke it at the bottom. The upper part remained in tact and was re-installed. The lower part will go in the trash and I couldn't care less. Maybe I'll learn another lesson in the future?

Draining the whole 2 gallons out of the radiator and replacing the thermostat was pretty easy. Now I became concerned with the air that was in there and spent the next 3 hours making an EPA disaster zone in my garage and wasting about a half a gallon of coolant on the floor before I realized the obvious.

Start the truck and wait for it to get to temp. Sure enough it sucked the coolant in and I refilled it as it went. Waited more, and watched it rise...Sqeezing the upper hose over and over to get the air out. Oh, it's not stopping. Shut it off but it was too late. Spilling everywhere. Again, oh that's just air coming out. I'm winning...

After the 3rd time of watching this happen I finally realized the obvious. The air is out, you're boiling the coolant and it's going to go somewhere moron.

I made this a bigger deal than it had to because I was so concerned about the air in the system and I have no idea what I'm doing. Once I decided to put the cap on, things went much better because I realized pressure reduces boiling temp. I still have no idea if the thermostat was bad, but it's got a new one and new coolant...many times over. Cleared the code, but the light remains.

I hope the engine check light goes away. I also found out, an all of a sudden throttle position sensor code is directly related to coolant while I was doing this. That one cleared WTF

I'm going to change the transmission fluid tommow. (yes I bought the metal nut to replace the plastic one for the filter) Wish me luck

Edit: I just realized this was a 5.7 thread. I can't delete/move it. Sorry about that. If it helps, I'd have done the same thing to a 5.7

The 6.4 is way harder to bleed the air out of simply because there is no rad cap, you have to bleed it from the reservoir.

Sorry you had such a hard time with this, @U&A went thru bleeding his 6.4 and it wasn't easy. I think he said he was going to invest in a vacuum fill tool for next time...

 

[HEMIMANN]

I'm trying to remember what we did on my 6.4 Hemi. I think we poured new coolant into the upper rad hose until it started coming out of the passenger side block drain plug hole. Put the plug back in and fill until it starting coming out the thermostat housing jiggle pin holes. Then button up the upper hose and fill the rest from the pressure reservoir.

BTW, you can't get the driver's side block drain plug out without lots of other parts removal - it's behind the steering column.

You always want to find a way to fill from the the bottom up to burp as much air upwards as you can.