Hi - Just bought a used 2012 JK. I went to flush and change the coolant, but I can only get 3 qts using the petcock. Total should be about 11 qts. I'm running it until the thermostat comes on and the heat is good. I picked up a OEMTOOLS 24444 System Refiller Kit that attaches to my shop air. It's main purpose is to suck the air out of the system using a vacuum, I was thinking I could use it to suck the old coolant out as well. Any suggestions? Anyone else have the same problem? Thanks

 

The petcock on these suck. Are you sure it is fully open? You can always pull the hose

 

+1....they're terrible. Better off pulling the hose. I pull lower hose to drain, and even pour distilled back in through the top hose to flush old coolant out. If you're doing this, good idea to change both thermostat and the coolant sensor at the same time if you hadn't considered that yet.

 

Yes, I've found the best method is to pull the hose, fumble it, manage to miss all five buckets and drip pans while fighting for control, and get coolant all over the garage. I mean, that's how I usually do it.

 

That sounds about right! I am lucky to have a bit of space that I drive back off the driveway in some grass where I don't care if I make a mess or not.

 

Be sure to remove the radiator cap so that the coolant does not vacuum lock.

 

Thanks very much. Pulling the hose tomorrow.

 

Pull both hoses and replace them for $20 if they need to be. The constant pressure clamps are a must in my opinion. New cap is $2 so I usually just do that also. Depending on mileage could be a the time to do thermostat also and keep the old as a spare for the trail. I have a very large air compressor and purchased an Air Lift. It is amazing and makes this job super easy. I pull the hoses once a summer and put in new coolant for the summer beatings it will get in hot weather.

 

Thanks. Good advice.