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Radiator petcock won't drain

JimNH

JK Enthusiast
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Mar 24, 2020
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162
Location
Nashua, NH
Trying to drain rad o 2008 JK. Turned the petcock and it won’t drain. Now I can’t even tell which way is closed. You’d expect closed to be with the lever horizontal but I think closed might be vertical? Do you have to turn and pull? How to fix if clogged? Thx.
 
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North Eastern, Maryland
Follow Up: Just wanted to add, that I'm concerned with others who have this same issue. One way the fluid doesn't drain, could be due to the mixing of HOAT with OAT coolants. Mixing these coolants would cause a chemical reaction that turns the coolant into a gel, crystallizes then hardens. If the coolant doesn't flow as it should, then one could have this chemical reaction or metal/rust fragments in the system. I'm leaning towards the chemical reaction of different coolants.
 
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JimNH

JimNH

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Mar 24, 2020
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162
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Nashua, NH
Update - there is conflicting info on the interwebs about the petcock. Some videos and sites say turn 90 and some say 180. you have to turn 180 to get it to open. the first 90 is easy and then there is some kind of stop, then you have to try harder to go another 90 (counterclockwise) to open. why not just a 1/4 turn ball valve?

I have now completed 3 cycles of filling and draining with DI water. the fluid coming out is orange - so I am guessing HOAT which is good - but it could also mean Dexcool. So even though the coolant looked pretty good, I plan to keep going until I get mostly clear water out before refilling with G-05 Zerex. In the end, I probably did not need to do this at all.
 
Joined
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Messages
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Location
North Eastern, Maryland
For the record and for those who maybe unsure as to what coolant should be in your vehicle, best check your owners manual. But after scanning a full list of all the wrangler owners manuals, at or about 2014 jeep change coolants from HOAT to OAT. In Jim's case the HOAT is the correct coolant assuming any previous owner did not mix these coolants without reading the owners manual first.
 
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JimNH

JimNH

JK Enthusiast
Supporting Member
Joined
Mar 24, 2020
Messages
162
Location
Nashua, NH
that is kind of why I wanted to do this even though the coolant seems OK - I have no idea what the maintenance history of the vehicle actually is, but now I will have a baseline - new coolant, oil, brakes, plugs, wires. I shoudl also check the diff fluids - I'll get to that eventually, but my wife wants her car back.
 
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