burping system?

I figure that I should flush my coolant system, People talk about burping the system, what is that, and what all do I need to do to flush my system?

park the Jeep with the nose down hill and remove/loosen the temp sensor at the rear of the intake fill the bottle till water comes out the intake hole.

bigpimpinben said:

I figure that I should flush my coolant system, People talk about burping the system, what is that, and what all do I need to do to flush my system?

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Burping the system means removing all the trapped air in it after a system is drained and refilled. There are a few ways to do it, depending on the year and the equipment. The easiest and fastest way is to use a Sun cooling system flush machine, the machine gets put between the radiator top bung and the top hose, interuppts the flow. It draws all the old coolant out, about 95% and pulls a vacumn on the system for about 5 minutes. Then the exchanger/flusher is reversed and new coolant is pumped in, flows thru the machine and that pushs the last 5% out and replaces it with new coolant, with it's clear hoses you can see the old nasty stuff coming out and the new fresh green stuff going in, then remove the two adapters and reconnect the top hose to the radiator. Thats the automated method.
Manual method depends on model year. On the 'open' cooling system that has a radiator with tanks you basically fill the rad with new coolant, start the engine and allow it to run, thermostat opens and sucks in the new coolant and you just keep adding it to the radiator filler bung, keeping the level in the bung to where you can see it. each time you fill it and the new cold coolant goes into the engine the tstat will close and you have to wait for it to open. Initially you will see big bubbles at the filler. As you get the major air out the coolant will start to look like fizzy green soda, thats also air only it's mixed with the coolant just like carbonated soda. You just let it run and like carbonated soda after it sits for a while the air will escape in to the atmosphere. The goal is to get as much air out and as much coolant mix in as possible. I do a rev or two at the end so the engine sucks in the max amount of coolant, do a quick top off and quickly put the pressure cap on. Then I let the normal process of the overflow bottle work. As the engine gets hot the cooling system will push the coolant/air out the over flow and the air will escape thru the overflow and when the cooling system pulls cooalnt back in from the bottle there should not be any air in the mix by then.
The closed system works similar except you don't have the radiator filler bung, you get the system full by pouring coolant into the back of the engine thru the temperature sender that you remove till you top it off and the engine is not running for this, replace the sender. In that system air will collect in the pressurize bottle which acts like the top tank on a radiator and the trapped air will remain in the pressure bottle gradualy replacing the coolant in the overflow bottle with air. The closed system is a PIA to bleed compared to the open one but it's dooable, just takes a bit longer. Either takes at least a half hour and for a major system drain like a new water pump seems to take about 45 min of idleing to burp.
Ford also uses a closed system on alot of their cars even now only they treat the pressure bottle like a radiator tank, use a normal pressure cap and have an over flow bottle that works just like an open system. Ford has used that method for YEARS, we had it on a 61 Ford Country squire and I seen it on a few other vehicles recently. Guess with the wedge shaped noses of todays vehicles the ability to lose 4" of radiator tank and put it somewhere else is handy for the designers.

I'm having the same problem.....but just to make sure here's the situation.

I own a 90XJ which I bought 1month ago. I noticed that the engine was running quite hot (which I know is a common problem) and I checked the coolant and noticed right away that it was well over due for a coolant change.

I did a flush and fill and it was running even hotter. I figured I'd replace the thermastat just to be on the safe side. I refilled and tried to burb the line.....but its still over heating.

I parked my Jeep on my driveway nose downhill and removed the temp sensor and filled till it came out the hole and I'm still overheating.

I'm assuming that I still have air in the lines but I'm at a loss to resolve this. I don't think it could be from anything else since the vehicle wasn't over heating before I changed the fluid.

HELP PLEASE

I filled my via the upper radiator hose reattach the hose. Then filled the "turtle" (new term I learned on here and will try to get to catch on) and it'll gurgle around. Let it all settle and check and fill as nessesary, pull the temp sensor off the back (make sure your car is parked downhill before starting this whole shibang, I pulled mine up on some landscaping bricks so it was a pretty tall angle). Then put fluid in back there, this will get fluid behind the tstat. Now everything should be full of fluid. Let it set (I made the mistake of trying to start the engine with the sensor out, fluid shot out everywhere it was cool!) Then check everything again. I put the sensor back in and left the cap off the turtle. Making sure there was enough fluid in the turtle I started the engine. Now is the time to keep an eye on your temp as well as the bottle. Chances are you will still need to add fluid. (The reason for putting water in everywhere first was so the tstat would heat up and open) Then once it warms up it will circulate and push the rest of the air out through the bottle. So you should still be watching the bottle. Add as needed then put the cap back on and you should be good to go.


Now granted this may not be the ideal way to do things but I had to experiment because I couldn't find a direct answer to my question. I've had absolutely no problems with overheating and air pockets.

Also a problem people don't realize is they put too much antifreeze in. Put only enough to lubricate things and keep the water from freezing. Antifreeze doesn't dissapate heat as well as water so you want as much water in there as you can.

Also go by the grocery store and pick up some distilled water before starting all this.

WobblesXJ said:

Also a problem people don't realize is they put too much antifreeze in. Put only enough to lubricate things and keep the water from freezing. Antifreeze doesn't dissapate heat as well as water so you want as much water in there as you can.

Also go by the grocery store and pick up some distilled water before starting all this.

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Antifreeze serves several purposes, first and foremost it prevents water from freezing in cold weather. Second it provides corrision protections to components. Good article HERE on that and there are more elsewhere. As far as cooling properties, thats not an issue.

RichP said:

As far as cooling properties, thats not an issue.

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I'm just curious so don't think I'm bashing you or anything but if the antifreeze's cooling properties aren't an issue is there another reason why it's not recommended to use just coolant with no water?

Also I did say lubrication and freeze protection were it's main points. (by lubrication I figured corrosion protection was included)

Antifreeze should always be mixed with water, you should never run straight antifreeze. Like he said, you can run 50/50 but it's not necessary. I usually run 70/30, more water in the summer. Antifreeze alone is too thick, as it evaporates it'll leave behind alot of residue inside the system. I was told to "burp the system" just fill up the radiator... run the vehicle until the thermostat opens (rad cap off) and watch until it swallows up the fluid and add more, repeat this process until the system is full. Don't top off the overflow jug all the way! There needs to be room in there for overflow! I usually keep the oveflow jug about half way full.

WobblesXJ said:

I'm just curious so don't think I'm bashing you or anything but if the antifreeze's cooling properties aren't an issue is there another reason why it's not recommended to use just coolant with no water?

Also I did say lubrication and freeze protection were it's main points. (by lubrication I figured corrosion protection was included)

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Actually its main to reasons for existence are corrosion protection first, the properties of the EG allow it to bond with the surfaces in the radiator, specifically aluminum, to protect it from the impurities, minerals and other chemicals in the water. There is alot of other data available.

barillms said:

I was told to "burp the system" just fill up the radiator... run the vehicle until the thermostat opens (rad cap off) and watch until it swallows up the fluid and add more.

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The reason this won't work is because there is no fluid in the engine to heat up and open the tstat. You need to add fluid into the engine in order for the tstat to open.

Would like to insert something at this piont....
BURPING IS ONLY NECESSARY ON THE CLOSED SYSTEM
Not slamming those w/the closed system,just making a statement,
People who have or have switched the closed system does not require burping
We noe return to our regularly scheduled forum...thank you and good night :laugh3:

50/50 as strong as you want, pure anti-freeze will freeze before the 50/50 mix.Also a mixture of anti-freeze and water is a better coolent than 100% of either.
You can spent lots of money for so-called summer coolent but your buying the water.