How do you BURP! the cooling system??

[Blackjeep]

Wow did I have fun on a little project yesterday. My Cherokee is a 90 with a 4.0 motor. The fitting that comes out of the valve cover for crankcase venting was leaky, torn up and not doing it's job. I've replaced it once for about $40, as I recall, and it lasted about 5 years. I figured I could save a buck and do something a bit more permanent. So I worked up a fitting that matched a 1/2 inch hose (that now goes directly to the airbox) and screwed it into an aluminum plate that I popped riveted to the valve cover. This required the valve cover to be removed, to keep from getting the drilling waste from landing inside the motor.

In the process of trying to remove the valve cover, the heater hose and upper radiator hose prevented the valve cover from being removed. I pulled the hoses off. The ol' Jeep was tilted downhill, so a bunch of coolant belched out all over the place (so much for planning ahead).

So now I've got air in the system. I guess it needs to be "burped". It's not running hot, but I figure it's best to be careful.

Would someone let me know how to burp the system? Thanks!

[XLT03]

It'll burp itself. I'm assuming that you do not have an aftermarket flush kit on your cooling system. Fill your radiator with coolant and don't forget your overflow bottle. Start engine and let it warm up with the radiator cap off. Turn your heater control to hot. When the thermostat opens up the coolant will drop in the radiator- top it off and replace rad cap. If car has flush kit, with engine off and cool remove rad cap, turn heater control valve to hot. Unscrew the cap on the flush tee and add coolant at the radiator, when full the excess will come out of the flush tee. Cap flush tee and replace rad cap. Baby has now been burped. Time for a ride!

[Blackjeep]

Originally Posted by XLT03

It'll burp itself. I'm assuming that you do not have an aftermarket flush kit on your cooling system. Fill your radiator with coolant and don't forget your overflow bottle. Start engine and let it warm up with the radiator cap off. Turn your heater control to hot. When the thermostat opens up the coolant will drop in the radiator- top it off and replace rad cap. If car has flush kit, with engine off and cool remove rad cap, turn heater control valve to hot. Unscrew the cap on the flush tee and add coolant at the radiator, when full the excess will come out of the flush tee. Cap flush tee and replace rad cap. Baby has now been burped. Time for a ride!

This 90 4.0 doesn't have a radiator cap, just a pressurized plastic bottle. I guess it's what they call a sealed system. The reason I asked was I saw a post the other day that mentioned burping the system by pointing the front end up-hill (I think) and loosening something (?) to get the air out. I'm fuzzy on the details.

Thanks for your reply!!

[gpoe]

Try this article

http://www.olypen.com/craigh/cooling.htm[/url]

[jaykaye12]

i have same model/engine. I just let it run with the cap loose for a minute, to create some vacuum in the system, shut it off, then barring that i don't have to add more fluid, tighten the cap. It seemed to do the trick.