• NAXJA is having its 18th annual March Membership Drive!!!
    Everyone who joins or renews during March will be entered into a drawing!
    More Information - Join/Renew
  • Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

2001 XJ Radiator Fill Issues

Mighty.Mighty_XJ

NAXJA Forum User
Here's the issue: I can't fill the radiator. I get about a quart of coolant in and that's all she'll take before it comes back out (engine not running).

I have flushed the cooling system extensively, both with a cleaner and just water, over & over & over. I don't have anything to introduce pressure to the flush, but I bought an amazing nozzle on Amazon that can be inserted into the hoses and doesn't allow fluid to splash back in my face. I installed all new hoses, t'stat/housing & water pump.

I did not properly bleed the system (thought I had) and last week the coolant came bubbling out before getting to norm operating temp. I was just in observation mode, not driving it, so no harm no foul, and the Jeep was not driven since the repairs were done. Drained and flushed again, this time no chemical, just water. Using a hose & nozzle, fluid flows freely & cleanly thru the radiator from filler to draincock and back from upper hose opening to filler. Can anyone help me figure out what's going on & how to solve it? I think the rad might have a clog, but when I use the hose, the water seems to flow thru just fine. I'm stumped & really don't want to put in a new rad.
 
How are you filling it? Are you going through the radiator cap to fill it? If so, pull the top hose and fill through there. I rarely fill mine through the cap, it never seems to work properly. Once you think you have it filled all the way, put the hose back on the motor. SLOWLY fill the rest through the cap till it bubbles back up at you. Also, fill the overflow about half way. Start the motor and check for leaks with the system completely closed. Once you're sure there are no leaks, take it for a quick spin around the corner. Also, make sure you have the heater on so the fluid goes through the core. After it's fully up to temp and you're sure the t-stat is open go back home. Once home check your overflow. If it's still at the same level you filled the system. However, the overflow will suck in more fluid as the system is up to full temp if the system is not full. Keep checking for the next couple days. Once the overflow stays at the same level you're good.
 
I'm guessing you have an air lock. When refilling without a vacuum refiller, I remove the upper radiator hose at the thermostat housing and then refill from the filler neck. When coolant reaches the thermostat housing and starts pooling put the upper radiator hose back on. It should take about 6 quarts. The OEM thermostat have a jiggle pin that goes up top side/up to help bleed the system.
 
Check to make sure you have a 13psi relief cap. If you don't the coolant will blow off somewhere else when it expands. I buy the Stant caps with the lever from Amazon, don't need the lever I just like them.

Also I guess you know not to put raw water in the engine. You should definitely mix 50/50 coolant and distilled water.
 
There are little flush kits sold at the parts stores that have T adapters. Sometimes helpful to put one of those in the top heater hose and fill from that.

I use that, but I don't fill into it. I remove the cap to remove the vacuum lock. Then fill at the radiator cap. Replace cap. Crank the vehicle, heat to full, and run to temp. I'll SLIGHTLY open that tee's cap while the engine is running (wear a glove, this may splash- but again you want to just BARELY crack it). This provides a convenient way to get air out of the engine. Once I'm getting a steady stream oozing out of that tea, I cinch it back down. And, done.

Just did it last night.

EDIT to add- those tees CAN fail, though I've only seen it happen once personally. I do wish there was a metal version available.
 
Also, make sure you have the heater on so the fluid goes through the core.

Fluid is always flowing in a 2001, there is no heater control valve!
 
Did you drain the block before trying to refill with coolant?
 
Did you drain the block before trying to refill with coolant?
How's that? You mean pulling a block plug? No. I just removed the radiator end of the lower hose.

ehall said:
Also I guess you know not to put raw water in the engine. You should definitely mix 50/50 coolant and distilled water
Yes, I know, but I flush with plain water.

Thanks for the tips guys, Tomorrow I'll check these out more carefully & implement what I can. Getting ready for work now.
 
Back
Top