resharp001

Also, you should only need 2 gallons of full strength, then distilled water. Capacity of the system is ~6 gallons if I recall

EHarris

From what I read I was planning on just dumping in just over 3 gallons of the above without any distilled water or anything. Yikes I may have to look this up? I figured the distilled water was only when flushing it.

tjkamp

Just swapped my rad this last weekend. If you are wanting to change the fluid completely the whole system only holds 13.4 quarts (3.35 gallons) it won't all come out.

If you know your coolant is still good (I had my system flushed about a year ago, and just changed the lower hose, water pump, and thermostat about a month ago), then leave the upper and lower hoses till last. When you disconnect the lower hose pinch it up against the alternator, and bend the lower back against the AC piping, and you will lose less than a gallon of the old.

If you haven't had a flush recently, let it all run. Pull the thermostat housing to help drain it. When you go to refill it, leave the thermostat housing loose as you fill it, until fluid runs out. This will help prevent vapor lock. When you do start the Jeep again, run the heater on high.

resharp001

what the hell was I thinking with my previous comment....y, this sounds more right. idk where i pulled 6 gallons from my mind....but, knew 3 gallons of full strength coolant was way too much.

you want a ~50/50 mixture. Don't pour in 3 gallons of full strength coolant! You might have seen people dumping in 3 gallons of PRE-MIX 50/50 coolant. You just have to be aware of if you're buying full strength or pre-mix, cuz they sell it both ways.

It sounded from the post #8 you bought this from RockAuto -
https://www.rockauto.com/en/moreinfo...471660&jsn=258

The jugs will clearly state if it's pre-diluted though....like this -
https://www.morris4x4center.com/mopa...E&gclsrc=aw.ds

EHarris

Wow I'm so glad I posted about this. I had no idea Mopar sold both.

So is my process now 1 gallon of the Mopar HOAT coolant and then 1 gallon of Distilled water mixed in a bucked? That would be 50/50.

Rednroll

I typically keep an empty gallon coolant jug around, clean out a milk gallon jug if you don't have one for the 1st mix. Pour 1/2 of the undiluted stuff in the empty jug, then fill both jugs up with with a 1/2 gallon of distilled water each. I purchased 2 gallons of the undiluted, and a few gallons of distilled water from Meijer for .45/gal.

The unmixed HOAT is P/N:68048953AB, the pre-mixed HOAT is P/N:68051212AB. HOAT is what you want for your 3.8L

From my local dealership, I paid $16.77/gal of 68048953AB, Pre-mixed (68051212AB) was $10.75/gal So the mixing it yourself, is the cheaper route. Pre-mixed is the more convenient route.

resharp001

It doesn't have to be perfect. 50/50 is a typical standard. If you were in a super cold climate it's probably more like 60/40 or 70/30 coolant/water mix. It's not an exact science, the point being that 100% coolant doesn't protect you much more than 100% water. I'm no scientist, and my knowledge retention on things I'm not a geek about isn't great, but I generally have read up on this stuff in the past out of curiosity. Might get some more scientific people chime and teach us all about the chemistry behind it.

Are you going to flush the entire system, purging the old coolant, or are you just swapping radiators and filling back up?

If you’re just swapping radiators and filling back up, definitely add ~equal amounts of full strength coolant and distilled. I wouldn’t use a bucket to mix it as you might add contaminates. I would pour in half bottle of coolant, then half gallon of distilled, then pour the other half gallon of distilled in to the coolant bottle creating a full gallon of 50/50 mix to keep adding in.

If you are flushing the system to purge all the old coolant out of the block and heater core lines, what you end up with is distilled water in the heater core, heater core lines, and the block. (If you haven't flushed a system before, let us know. It's not hard, but takes a few cycles of draining, filling with distilled, cycle, repeat.) After installing new radiator, and considering you probably have 1 – 1.5 gallons of water existing in the system, add 1 – 1.5g of full strength coolant. You know (now) that the system holds little over 3 gallons total. Error on the side of more coolant than water in the mixture, but target 50/50 if you can, topping off with what you think is appropriate (full coolant, water, or mixture). Usually you will pour some coolant back down the upper rad hose until it stops going in prior to clamping that to the radiator.

EHarris

I'm going to be replacing the radiator completely along with upper and lower hoses. I have a brand new AirLift to use for this also so that's why I was saying mix in a bucket.

resharp001

Wasn't familiar with AirLift system. Watched a couple videos. Looks like pretty easy way to bleed the system, but you're still dumping most of that coolant mixture right on in I'd think, then just using the airlock to bleed.....unless I'm missing something, you're not using that to fill the entirety of the system. I bet that is handy if you're changing radiators all day long and have to send customers on their way vs. at home having to bleed/burp the system and top off once or twice.

EHarris

Yea it definitely isn't necessary but there will be 3 friends doing radiators on Saturday so we split it 3 ways to make sure the system is air tight. Figured the dealer would most likely use a similar set up.