Woo first post. Forgive me if im redundant but i couldnt find the answersi was looking for.

First, i blew my radiator so im changing it. Do i need to add any trans fluid since the trans cooler is in the radiator?

Second, a friend told me to make sure not to get any air bubbles in the fluid. Fatchance since i took the lines loose at the radiator. Is this a problem and if so how do i purge the system.

 

Check the trans fluid but you won't lose much on a radiator swap.

Slowly fill the coolant bottle to the top at first. Squeeze the upper radiator hose and wait for the coolant to go down in the bottle. Start it and run it while watching the bottle with the cap off. Add to the full line as needed. Go to Napa and get yourself a coolant bottle cap before-hand. 703-1396.

 

Thanks boss. I got my new radiator today so I'll be putting it in later.

 

Get the cap, too?

 

......and when the old rad is out, u can just about change the t-stat and water pump blind folded before the new rad goes back in.

Air bubbles in the tranny fluid line is a non-issue. With regard to the cooling system, after it's all buttoned back up, let it idle with the bottle cap off 'til it reaches operating temp. Keep an eye on coolant level in the bottle, needs to be some coolant in the bottle all the time.

 

I got a new pressure tank and cap, did the water pump 2 weeks ago before the radiator went and did the thermostat when i did the pump. It sure would have been easier to do the pump with the radiator out but oh well, scat happens.

I also burped the cooling system using the water temp sensor on the back of the head. BIG deal with these trucks is to get all the air out of the head.

 

I have never understood what removing the sending unit in the back (the lower part) of the head accomplishes. The back of the head is lower than the front of the head (vehicle on level ground) and air naturally rises to the highest point in a liquid, especially when the liquid is rapidly flowing/circulating from a low point to a high point. Liquid (and any air) enter the back of the head (from the lower/back end of the block) and exits the front of the head (the higher end). The bottle is purposely located up high so that air will separate from the liquid and only liquid is returned to the cooling system from the bottle. That's why it is critical for at least some coolant always remain in the bottle. If the bottle ever gets empty, air is drawn into the cooling system. This is true either a closed or open system.

 

Ya i couldn't tell you why! But it works like a dream and a ton of air comes out. When i first got the jeep it was constantly overheating. Burped the head and and it stopped immediately.

 

Guess there's always 1 XJ out there that defies the laws of physics.

 

It's beyond me but it works!