Forum Index
Jeep Horizons HomeLinksJeep Horizons Tech Write-upsJeep newsLand useContact

 Watched TopicsWatched Topics   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

bleeding air out of cooling system?!?!?!

Post new topic   Reply to topic     Forum Index -> Cherokee Forum
View previous topic :: View next topic  
Author Message

Joined: 05 Jan 2005
Location: niles, michigan

PostPosted: Wed Jan 05, 2005 6:13 pm    Post subject: bleeding air out of cooling system?!?!?! Reply with quote

I bought a 87 Cherokee last week that needed a water pump.
I replaced the water pump, thermostat, and upper hose. I filled up the system via the upper hose before I connected it to the radiator end and then filled up the coolant tank after the motor had started to warm up. I already knew that the closed cooling system sucked, but I can't get the air out of the upper radiator hose. The coolant tank is full, and the jeep wants to overheat, but the upper radiator hose is still cool and feels like it's full of air. The heater is blowing out cold air. The goofy upper radiator hose is shaped like a "U", and goes under the AC compressor lines.
How can I bleed this system or get the trapped air out? I tried driving it around but it gets too hot because of the trapped air.
ANY help would be GREATLY appreciated. I just want to have this Jeep as a toy, and got it really cheap. I don't want to spend $500.00 converting it to an open cooling system.
Back to top
View user's profile Send private message
Pissed-Off Admin
Pissed-Off Admin

Joined: 23 Jan 2004
Location: I knew it...I'm surrounded by Assholes!

PostPosted: Wed Jan 05, 2005 7:27 pm    Post subject: Reply with quote

OK, first off, it's best if you jack up the rear of the Jeep to raise the back of the engine, which will provide a more complete air purge.

With the engine off, fill the system until the coolant bottle is topped off (there is a little post inside the bottle that is visible with the cap off, fill to the top of this post). Leave the cap off and then unscrew the coolant temp sensor located on the top of the cylinder head at the rear on the driver's side (see the pic...yes, I know 'Gauge' is spelled wrong), and slowly start to pull it out until you hear air escaping.

You won't have to pull it all the way out...the sensor extends down beyond the threads. When coolant starts to escape, screw the sensor back in and tighten it. Then top off the coolant bottle (if necessary), and install the cap. Finally, start the engine. Once it reaches operating temperature, any excess coolant will be forced out through the pressure cap as the system stabilizes. This is don't be alarmed by the coolant escaping.

Never, ever unscrew the temp sender with the engine running, or start it up with the sender loose in its threads! Even on a cold engine. The sender will be launched into a low Earth orbit, and you will be left drenched in coolant, trying to figure out where the hell to get another sensor on a late Saturday afternoon. In other will make for a bad day.

Even the Jeep engineers admit the "closed" system was one of the worst mistakes Jeep ever made. There are a few different options for converting it to a open system. This one will cost you $2-300 but includes a new radiator. This one will cost you less then $100.


Good Luck.


97 XJ Sport with a bunch of stuff
Never argue with idiots, they drag you down to their level and beat you with experience
Back to top
View user's profile Send private message AIM Address Yahoo Messenger MSN Messenger
Display posts from previous:   
Post new topic   Reply to topic     Forum Index -> Cherokee Forum All times are GMT - 8 Hours
Page 1 of 1

Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Visit for write-ups, forums and clubs

Jeep®, Wrangler, Cherokee, Liberty and Grand Cherokee are copyrighted and trademarked to Chrysler LLC. is not in any way associated with or endorsed by the Chrysler LLC.
All other content is copyright Jeep Horizons 2004-2008.
Tech write-ups Links Discussion board Land use News Site Map Terms of Use

Powered by phpBB © 2001, 2005 phpBB Group