Burping a Rad?!

[Dangerous]

How one one Burp (bleed?) a Rad? I JUST read of doing this... and i'm gonna try everything to try and get my XJ to cool down. Everything is still stock ... New Water Pump, Fan Clutch ... Aux fan wasn't working, so i hooked it up to a tggle switch. But read this "Burping" thing and it got me all curious.

If there is a thread about overheating Cherokees, that someone has handy... maybe you could pass that along?

Thanks Folks!

 

[joe_peters]

Always post up the year, engine, trans, etc.

 

[Lowrange2]

For me, it depends on the year.

I'll usually pull the temp sensor out of the back of the head while I fill it. That'll get 95% of the air out of the system.

 

[Devilfrog]

Like this

 

[dobesrgrt]

My 99 has a little plastic plug on top of the radiator.

 

[bails85]

Frog you're a genius.

 

[O-Gauge Steamer]

Biggest issue, IMO, is that new thermostats do not have an air bleed hole in them as does the Factory T-Stat. I drill a 1/8" hole in the T-Stat just so that the air can bleed out faster.

Old school but, it works...

Drill the hole near the edge of the T-Stat making sure that it is not on the gasket surface.

The hole will not adversely affect the operation of the T-Stat.

 

[Dragonslayer]

Whenever I change the T-stat I drill a 3/16" hole in it (similar to O-Gauge) and then make certain that the hole is positioned up when installing. I then jack up the front of
the car before pouring in the coolant. Drive as normal. On my '93 XJ, I'll turn on
the heater a few times while doing this to purge any bubbles out of the core.
My '98 XJ does not need this as the coolant is constantly flowing through the heater core
by design. Later, I'll jack up the front of the car (again) while checking the coolant level.

 

[O-Gauge Steamer]

Mea Culpa! Should have said "install with the hole up". Forgot. Must be getting senile...

 

[techno1154]

Like this

That is a great idea Devilfrog. I am sure it work great being at the highest point in the water system.

Me, I have never burped my cooling system. Even a completely empty system I simply fill the radiator and close it. I then fill the recovery bottle almost to the top, run the engine up to temperature then let it cool a couple of times in the driveway. This allow the air that is in the engine block and radiator to work its way to the recovery tank and be replaced with coolant from the recovery tank. There is no need to remove the radiator cap again. That procedure have never failed me in the 14 years I have owned XJ's.

 

[joe_peters]

That is a great idea Devilfrog. I am sure it work great being at the highest point in the water system.

Me, I have never burped my cooling system. Even a completely empty system I simply fill the radiator and close it. I then fill the recovery bottle almost to the top, run the engine up to temperature then let it cool a couple of times in the driveway. This allow the air that is in the engine block and radiator to work its way to the recovery tank and be replaced with coolant from the recovery tank. There is no need to remove the radiator cap again. That procedure have never failed me in the 14 years I have owned XJ's.

Generally speaking "burping" is not required on "open" cooling systems--those systems with a recovery bottle versus a pressure bottle.

 

[Devilfrog]

I've always had issues with these motors ('00 Xj 4.0, '88 MJ 4.0, '92 YJ 2.5) retaining air, in either the head, or the upper rad hose ... sure it eventually bleeds off ... but I just wanted it out right off. I converted the MJ to open cooling using the '00's spare parts, and it took about a week to fully burp on it's own. So, I ordered another fitting for it as well. Just me, that's all ... guess it's not really needed but I have a lack of appropriately angled places in my driveway to speed burping. this way I don't need anything fancy or any waiting.