My 04.5 has 160K miles on it now and all I have ever done is a "drain and refill". The first time I started doing this, I did it twice in a relatively quick short period of time but then started doing it about every 40K miles or so.

Basically, I just open the drain **** and let it drain until it's empty. That releases about 4.5 gallons from my experience. I then replace it with 50 percent Zerex G-05 and 50 percent Distilled water....a gallon or so of one then the other and so on until full. I know this method doesn't get all of the old coolant out of the block. But, every time I change it, it comes out looking like new stuff. It's worked fine for me so far, so I don't see the need to "flush" it. FWIW, im still on the original water pump too.

..

 

Cat/Chevron ELC-1 is great coolant, and it may be compatible with everything, but HOAT may not be compatible with it. You need dual compatibility to ensure no issues.

 

Thanks so much for this write up. Just turned 100k on my 06. Followed your instructions and after 6 flushes with distilled, was still getting light rusty looking water. Refilled everything per your instructions and everything seems fine. THANK YOU AH64ID!

 

I subscribed to this thread, was going to do it myself but you gotta be more careful with the old antifreeze and didn't want to have to deal with it all, had the dealer do it when I had an alignment done, had my brake lines flushed too.

 

So bumping this old but excellent thread. I don't think anyone answered the above question. I did see the below text in the FSM and question where these "jiggle pins" valves are in relation to that high point on the heater core input hose. Where do these valves bleed the air to if the system is closed?

From the FSM:
NOTE: The diesel engine is equipped with two one-way check valves (jiggle pins). The check valves are used as a servicing feature and will vent air when the system is being filled. Water pressure (or flow) will
hold the valves closed.


Also, I see the FSM text below states only to fill from the overflow with the radiator cap closed. I take it when you do this complete flush your first fill is through the radiator cap and then you monitor your level and add to the overflow? Why would they say the system has check valves to bleed air, then go on to say below that filling from the radiator cap adds air and is bad?


From the FSM:
"Do not remove the radiator cap to add coolant to the system. When adding coolant to maintain the correct level, do
so only at the reserve/overflow bottle. Remove the radiator cap only for testing or when refilling the system after
service. Removing the cap unnecessarily can cause loss of coolant and allow air to enter the system, which produces
corrosion."

Thanks for any comments on the air burping and how it works in conjunction with the two one-way check valves???

 

As you fill from the radiator cap there is no water flow thru the jiggle pins, so the air can escape. When the system is full the water flow will hold the jiggle pins closed.

 

So I followed the instructions and had a small hickup, wondered what went wrong. I deviated my process from what I had always done on other cars and believe I followed the FSM instructions along with the set from the OP at the top of this thread. I believe for our trucks you are supposed to top the radiator off cold, fill the overflow/reserve tank and start it up and as it warms up it is supposed to suck any needed coolant/water from the reserve tank??? I did this on my first flush and when the engine got warm it sucked the top radiator hose flat and appeared to be starving for fluid. So I pulled the cap off and got wet and proceeded to pour water in through the cap and topped it off as the radiator water ran into the engine. All the following flushes and the final fill I performed this same pattern, filling the radiator after the thermostat opened. Isn't this incorrect from the instructions?? Like I said, this is what I had normally done on my other cars over the years, but thought per the factory service manual the fluid is supposed to be capped cold and it should suck any needed coolant/water from the reserve canister??? Guessing I had air in there or something even though I topped it off and squished the top hose to try to get the air out of it when filling cold.

Anyone have a comment on this?

 

It's when it cools off it pulls the coolant from the recovery tank. I believe someone mentioned when filling the radiator cold to pull the hose loose that comes off the top of the head towards the back to allow air to escape.
That being said, when I flushed mine, I filled it without bleeding the air out and it took about 3 driving cycles, (warmup then cool down) to pull the coolant from the recovery tank such that all the air was removed form the radiator.

 

Thanks for the reply. I did pop that top heater core hose off the last fill after re-reading this post. I think I was still nervous from seeing the top hose get sucked completely flat on very first fill/warm up. I guess in 6 or so years I'll try it from the get go with that with the heater core hose disconnected for the fills. Having not disconnected it for my flushes must have been why the top radiator hose sucked itself flat?

 

Could a person do a flush, with soft water? Then possibly do a flush & refill with distilled water, before adding antifreeze-distilled water mix?

 

I think that if you drain and change on a yearly basis you really don't need to flush. Over time you will have swaped out all of the old coolant....just my $.02 worth.

Jim

 

You can do anything you want, but I wouldn't recommenced it.

Seems like a big waste of time and money when it lasts for 5 years.

 

I hope. Truck just rolled over 31K miles. So I thought I had better change the antifreeze. I have two gallons of the Zerex G-05 but they are at least six years old. Never been opened, aluminum seal never been broken.
Its ok to use those to supplement the other two gallon I need for the flush-Fill?
Its draining now and it drained the reservoir first, then I removed the radiator cap and it drained another 20 minutes or so. I did notice some sand in the bottom of the bucket. Flush with water when I get back
I am going to get some new Zerex. Will use the Jeep to go get those.

Thanks
biscuit

 

The 2 gallons is fine, do not worry about it's age.

I dumped my coolant in 2013, and it looked like it was off the show room floor, totally clean.

Listen to 64, I would not put tap water in there, regardless of anything, use only 50-50 factory or Zerex coolant.

 

Thanks Bonus. Yeah I had bought those years ago in case I needed some antifreeze if a hose burst or something. They have been on the shelf. I will use them and keep a newer one as backup. I bought some distilled water.
thanks
biscuit