Did I burp her right?

[demarpaint]

I got a burst of engery this morning and decided to do some winter prep work on my 08 Jeep Liberty 3.7L. I drained out the raditator and replaced the coolant, no flush just a coolant change.

I jacked the front higher than the rear and filled the radiator and over flow tank, started it and ran it with the radiator cap off, leaving some space for coolant to move and air to escape. When I was sure air stopped coming out I topped it off and put the cap on. As the engine cooled it would draw coolant from the overflow tank, I kept it topped up. About half an hour later I took the cap off the level was down about 3/4" inch so I topped it up and repeated the process. More air came out.

When I was certain the air stopped I topped it up again and ran it for about a minute and saw no bubbles, I capped it.

The heater was on high and temp was at its normal position.

Is it necessary to repeat once more or am I GTG?

My Fords I bleed thru a heater hose, but I have a Prestone T Flush unit installed I don't have one on the Jeep.

TIA

 

[hate2work]

Sounds like you did a good job, just check the coolant level a few more times over the next couple days to be sure.

 

[bmwtechguy]

If your heater core is producing good, hot heat consistently, you are at least 90% there. Check it again the morning after a good hot drive and top it up if needed.

 

[demarpaint]

Thanks Guys. If there was a little air in the system it will escape on its own? Is there a need to run it a third time with the cap off. I was actually surprised how much air came out the second time. But when I capped it the second time there was no air coming out for at least a minute before I capped it off.

 

[mechtech2]

For my personal cars, I don't flush either. I drain and refill.
Flushing is for special needs.

You should have noted what came out, and compared it roughly to what went in. That'll tell you if you are full!
Most systems will self correct, given time and drive cycles.
A rare and occasional stinker will refuse to bleed properly, but most will be fine with some driving.
Keep an eye on her each day until you see it stays the same, and you get sick of checking it.

 

[Drew99GT]

I've found in most cars that if all you do is drain the radiator, you don't have to burp it. When you start digging deeper into the system, especially if the thermostat comes out, then the coolant in the engine block drains out in parts and air becomes a problem when refilled. It's why I drill a small hole on the thermostat if it doesn't have a jiggle pin. Helps air get past the thermostat when refilling.

 

[eljefino]

If you keep checking under the rad cap you're always going to find a "bubble". But it's actually a vacuum bubble (if there were such a thing) as the bubble grows until it forms enough suction to pull coolant up its little hose from its lower overflow bottle.

Another good test is with the cap on, squeeze the upper hose. If you hear coolant gurgling in and out of the overflow you're in good shape.

 

[Chris142]

There is a bleeder where the upper hose goes onto the engine. Did you remove it when you refilled the engine?

 

[demarpaint]

Originally Posted By: mechtech2
For my personal cars, I don't flush either. I drain and refill.
Flushing is for special needs.

You should have noted what came out, and compared it roughly to what went in. That'll tell you if you are full!
Most systems will self correct, given time and drive cycles.
A rare and occasional stinker will refuse to bleed properly, but most will be fine with some driving.
Keep an eye on her each day until you see it stays the same, and you get sick of checking it.


I collected what I drained and made my AF distilled water mix based on that. I'm within a few ounces of what I drained. I'm a little higher in the overflow tank than before, a tiny bit missed the measuring container. But I'm real close.

The heat is uniform and very hot. I'll keep an eye on the level the next few times I use it.

 

[demarpaint]

Originally Posted By: Chris142
There is a bleeder where the upper hose goes onto the engine. Did you remove it when you refilled the engine?


No I didn't, it was a threaded allen screw, and it is lower on the engine than the radiator fill neck. I jacked the front of it, and made sure the fill neck was the highest point on the engine, when I burped it.

I only drained the radiator, engine was cold, I didn't flush it or run it. The vehicle is just about new, under 15,000 miles and this is just to keep the AF fresh and the system clean.

 

[bigmike]

Sounds like you did it right to me. I plan to do the same thing in my truck once my Amazon order of Zerex Dexcool comes in.

Did you pull the lower rad. hose or use the petcock?

 

[demarpaint]

I used the drain cock, it has a nipple on it, I hooked a 1/4 hose to it. That made for a nice neat job. It is nice working on something almost new and clean.

I changed the PS fluid, and drained and refilled the master cyl as well. I made sure I kept the level above the brake lines. I'm going to bleed the system next engergy burst I get.

 

[bigmike]

I'm doing a good portion of that myself this weekend (oil change, brake fluid flush, PSF flush).

I've had some difficulty locating the drain cock on my 4.8. I'm *supposed* to have a hose on the driver's side of the radiator for draining purposes, but it is missing.

I've looked for the drain cock and never have found it - I haven't gone over it with a fine tooth comb yet, but will do on Saturday.

I did enough Googling for one day trying to get info or pictures. My manuals don't help me in this situation either - that's how I knew about the hose to begin with.

If I get stumped, I might make a new thread and see if anyone here has ideas (besides pulling the lower hose).

 

[Vikas]

Don't you have long life coolant? Was it necessary to change it so early?

 

[demarpaint]

Originally Posted By: Vikas
Don't you have long life coolant? Was it necessary to change it so early?


Going by the book I changed it early, I'd rather be safe than sorry. I didn't flush the system, I simply drained and refilled the radiator. The Jeep will be three in December. With a concentrated mix I used less than a gallon of AF using a 55/45 mix.

I've used this method for many years, on other vehicles, an old mechanic buddy turned me onto it. This coolant is almost 3 years old and I wanted to refreshen it. This method IMO beats flushing the system and will keep everything pristine.

If at some point in the future it looks like a flush is needed I'll do it then.

 

[Chris142]

Originally Posted By: demarpaint
Thanks Guys. If there was a little air in the system it will escape on its own? Is there a need to run it a third time with the cap off. I was actually surprised how much air came out the second time.
Originally Posted By: demarpaint
Originally Posted By: Chris142
There is a bleeder where the upper hose goes onto the engine. Did you remove it when you refilled the engine?


No I didn't, it was a threaded allen screw, and it is lower on the engine than the radiator fill neck. I jacked the front of it, and made sure the fill neck was the highest point on the engine, when I burped it.




You still need to remove that allen plug. Your thermostat is in the lower hose. It has a Small juggle valve in it. If you don't remove it regardless of how high up the front end is you will get air trapped in it.

When you pull the bleeder and pour coolant into the radiator the coolant will go through the jiggle valve. Once coolant is coming out the bleeder then you can put it back in and continue to fill the Radiator.

This is why you had so much air left in it even after running it.

 

[demarpaint]

Originally Posted By: Chris142
Originally Posted By: demarpaint
Thanks Guys. If there was a little air in the system it will escape on its own? Is there a need to run it a third time with the cap off. I was actually surprised how much air came out the second time.
Originally Posted By: demarpaint
Originally Posted By: Chris142
There is a bleeder where the upper hose goes onto the engine. Did you remove it when you refilled the engine?


No I didn't, it was a threaded allen screw, and it is lower on the engine than the radiator fill neck. I jacked the front of it, and made sure the fill neck was the highest point on the engine, when I burped it.




You still need to remove that allen plug. Your thermostat is in the lower hose. It has a Small juggle valve in it. If you don't remove it regardless of how high up the front end is you will get air trapped in it.

When you pull the bleeder and pour coolant into the radiator the coolant will go through the jiggle valve. Once coolant is coming out the bleeder then you can put it back in and continue to fill the Radiator.

This is why you had so much air left in it even after running it.


Now that the system is completely filled what do you suggest? I have no problem doing this over again if need be. I checked the radiator level this morning and it was down about 3/4" after running it about half an hour on the highway yesterday.

The level in the overflow tank is now at the lower line, it was about half on inch over, so it drew in coolant from there. It took about 2 ounces of coolant to bring the radiator level to the top of the neck.

Thanks!

 

[mechanicx]

I think the air will all eventually make its way out of the cooling system. It would've been better/faster to open the bleeders when you initially filled, but the air is going to be forced into the top of the radiator and out the reservoir. Even though you have filled the system you can still open the bleeder and pour more coolant in and then close the bleeder when you see a steady stream come out the bleeder.

 

[demarpaint]

I might just remove the radiator cap and the bleeder and see what happens. I have a feeling coolant is going to immediately flow from the bleeder, I'm pretty sure the second time I burped the system I got 99% of the air out. It's easy enough to check and see.

 

[mechtech2]

Bottom line for me:
If it was OK before, and the quantity drained is = to the quantity filled, this is a very good clue. And if the reservoir is staying at a good consistent level when cold, that is another.
Sounds like you are done.