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Refilling the closed system.


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Guys, I put my new rad in and filled the metal expansion tank thinking it would fill the rad and block up. Turned the truck on and it didn't work out as planned. In two minutes my temp gauge flew into the red zone and pegged itself there.

Where did I screw up. Should I fill the rad up first thru the upper rad hose first? Anything else I should do to make this go easier and correctly?

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Even after filling, there can still be a pocket of air trapped at the back/top of the head (right where the gauge's temp sensor is located). Some guys have had success raising up the back of the truck (to make the temp sensor the highest point in the block) and slowly bleeding the air out the sensor. Make sure you put a rag over the sensor while you're bleeding (so if it pops off you aren't showered in boiling liquid) and have someone manning the keys so if that happens it can be stopped immediately.

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I read a thread somewhere that talked about crap/sludge biulding up in older unmaintained engines causing over heating/ hot running issues. I don't know how to go about clearing the water passages in the block but after everything you've done thats the only thing I can think of.

 

If you look at this link ans look at the 3rd pic down on the left you can see how much crud is built up on the old freeze plugs. If that happened in the water passages too, it could definately constrict water flow.

 

http://gojeep.willyshotrod.com/HowtoWelshPlugs1.htm

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You could still have a pocket of air trapped in the back of the head.

 

I'm pessimistic about the idea. I've done it at least ten times before with absolutely no change in my temp. But for the sake of argument I'll pull that sensor again tonight after it cools down. BLHTAZ says he's done it with the engine off instead of on. I've tried it both ways. Anybody think it won't work if the trucks not running?

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Make sure you have plenty of coolant in your plastic bottle after you shut off the enjine. You will be suprised at how much gets sucked back in the system.

 

chico, i'm no expert on these here closed systems, but i'm a little confused. your thread says "closed system" and then later you state "you no longer have a closed system". did your mods change it over to an open system? I thought it was still a closed system.

 

regardless, recently i had overheating issues and shamelessly i have to admit it was simply low on coolant. well, almost out of coolant is more like it. :dunce:

 

so when i filled the bottle up to the proper level and ran the truck (in my driveway), i too continued to overheat and but my bottle continued to be empty. i found no leaks and my oil was clean so i wasn't sure what was up. until that is, i repeated the proces several other times, letting the truck cool completely after each shut off to see how much if any coolant returned to the bottle. each time i did this, as you probably have figured out where this is going, the truck ran cooler and a little more coolant returned to the bottle. yup, eventually the bottle filled up, stayed filled up after cool down, and the truck is running below 210 like a champ. on the highway with my newly functioning A/C :D on it runs "210-220, whatever it takes."

 

hopefully it's that simple now that you've done all that other work.

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Chico,

Not encouraging news for me :cry: . I have the same radiator showing up tomorrow and Mac's bottle some time next week.

 

I talked with the guy at Mac's about the extra fitting on the neck. I was under the impression that it is still a closed system. The neck that the rad cap screws onto they out-source, and this part just comes with the extra fitting. When/if the jeep overheats the rad cap pops{and I guess exposes the outlet?} and the excess fluid drains out. I asked him if I should plug it and he said no. Just run a small line to the "ground" and be done with it.

I hope you can figure it out. Good luck - Rich

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Rich that line that he told you to run to the floor is running to an overflow bottle on mine by the airfilter. I think there's still air in the system like Pete said. I went and checked it after a 4 hour cool down. The level in the second bottle was a little lower but the big story is that when I turned on the engine air bubbles started coming out of the second tank. I let it heat up again past 220* and it was still bubbling so I guess there is still air in there. I'll let it cool down and run it again. Hopefully it fixes itself like Wahoo's did.

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Rich that line that he told you to run to the floor is running to an overflow bottle on mine by the airfilter. I think there's still air in the system like Pete said. I went and checked it after a 4 hour cool down. The level in the second bottle was a little lower but the big story is that when I turned on the engine air bubbles started coming out of the second tank. I let it heat up again past 220* and it was still bubbling so I guess there is still air in there. I'll let it cool down and run it again. Hopefully it fixes itself like Wahoo's did.

 

Any possible way those bubbles were exhaust fumes?

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Rich that line that he told you to run to the floor is running to an overflow bottle on mine by the airfilter. I think there's still air in the system like Pete said. I went and checked it after a 4 hour cool down. The level in the second bottle was a little lower but the big story is that when I turned on the engine air bubbles started coming out of the second tank. I let it heat up again past 220* and it was still bubbling so I guess there is still air in there. I'll let it cool down and run it again. Hopefully it fixes itself like Wahoo's did.

That is strange? I talked to the guy at Mac's and I got the impression that it would only make it to the second tank if the the radiator cap popped? And to suck fluid out of the second tank??? I will have to give him another call - maybe I just heard what I wanted to? - Rich

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I don't think the overflow bottle returns fluid back to the system does it? I just thought it was a vessel to trap escaping pressure and over flow when your system pressures exceeded/over took the rad caps mechanical pressure pushing down from its spring....

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That's strange because mine's filled to the top. Once it heats up and expands it flows to the second overflow bottle. Once it cools down it gets sucked back into the system. Maybe I'm wrong but I thought that's what it was designed to do.

Pike where you at?I have the exact same settup as yours so what does yours do?

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Listen guys, I'm not crazy. Way back umpteen posts ago the discussion came up over whether to turn a closed loop system into an open loop system was better. Eagle has the same set-up as does Pike. Even BLHTAZ chimed in and said having to do it again he'd run with Eagle's set-up so not to have to mess around with the fan temp switch bung in the rad the the open system did not have because it was in the thermostat housing. Eagle used a Moroso metal tank. I bought the same one but realized it was easier to do it PIKE's way becuase the MOROSO tank required some modification to get it to mount. The MAC tank looks just like the original plastic one but is metal. Mounts the same way, hence my decision to buy it. Eagle said, fill it to the top, instead of halfway like the plastic tank and run a line from the top fitting to a second plastic tank to basically turn the closed system into an open system. Am I making sense or did I get it wrong?

EAGLE and PIKE, please chime in here.

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Jt, you mean because of a headgasket leak? There is no oil in my coolant and no coolant in my oil. I just checked for exhaust fumes in my coolant a couple of weeks ago with a block tester from NAPA. Fluid came out good to go so unless the head gasket blew today I don't think so.

Yes that was exactly what I was thinking... A blown head gasket doesnt allways place water in the oil, or vise versa..

Since you've already checked for fumes gladly rule that headache out of the way!

 

That's strange because mine's filled to the top. Once it heats up and expands it flows to the second overflow bottle. Once it cools down it gets sucked back into the system. Maybe I'm wrong but I thought that's what it was designed to do.

Pike where you at?I have the exact same settup as yours so what does yours do?

 

Ok I wasn't 100% with what you have going on.. I'm thinking that your bottles cap isnt like the cap on a rad (say 16psi spring loaded).. When you trucks temps rise the pressure is pushed out of the metal container into the overflow, making it closed, but not pressurized like a true closed system, so when you try to bleed the air its cooled + your system isnt pressurized making it more difficult to burp.

 

I think most of the efficiencies of the closed system is when you add pressure to water it raises the boiling point.. ie; boiling water on a high mountain.. it boils at a lower temp then it would on a beach. and that pressure from being closed helps to push the air out when you pop the temp sender.

 

Try this chico,,, plug that overflow then try and burp your system...

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Jt. the cap on my expansion tank is a regular rad cap, says 16 lbs vented.

The whole point of this set-up was to turn it into an open system without changing the rad style.

 

I just checked it again. The coolant level in the plastic tank was noticeably lower so the the system is still sucking coolant in. That and a lot less bubbles came out of the second tank. However it's still not running at 210*.

I'm goin to give it another cycle and try it again tommorow morning.

 

The temp is ten degrees cooler at the thermo housing down to 210*.

Of course the outside temp dropped 20* and it's raining. I also don't have the fan shroud on the mechanical fan yet or the electric fan hooked up yet. Would running that electrical fan nonstop on a switch really lower my temp a good amount by drawing air threw the driver's side of the rad.

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if you're still having problems with it taking coolant down the blocks on these get airlocked bad and you won't be able to fill it,

 

try taking off the heater hose from the thermostat housing and filling it through there. also if you install a thermostat drill a small hole in the metal and point it at 12:00 to let air through

 

filling it through the therm-housing is the best way i have found yet

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Jt. the cap on my expansion tank is a regular rad cap, says 16 lbs vented.

The whole point of this set-up was to turn it into an open system without changing the rad style.

 

I just checked it again. The coolant level in the plastic tank was noticeably lower so the the system is still sucking coolant in. That and a lot less bubbles came out of the second tank. However it's still not running at 210*.

I'm goin to give it another cycle and try it again tommorow morning.

 

The temp is ten degrees cooler at the thermo housing down to 210*.

Of course the outside temp dropped 20* and it's raining. I also don't have the fan shroud on the mechanical fan yet or the electric fan hooked up yet. Would running that electrical fan nonstop on a switch really lower my temp a good amount by drawing air threw the driver's side of the rad.

well crap! OK well you must be getting more then 16psi for it to be pushing past the rad cap then right??? can you open the cap and let the truck get warm without coolant going everywhere?

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