I recently had the infamous heater core O-ring leak, and also a leak in the throttle body heater plate. So replaced O-rings (what fun), and did a throttle body heater rebuild. Decided to replace all coolant hoses since it's 8 years old with 120k miles.
I did all that and everything worked fine. In about a week, came out of a store and saw a large puddle(maybea quart) of antifreeze underneath. Thought...that has to be from the person that parked there before me and went home. Then saw the coolant level was down so filled it.
I drove it maybe 200 miles, then checked and saw the coolant resevoir was near empty. I looked under the vehicle and saw antifreeze on all components (axle, diff, air spring, etc) on the left (drivers side) near the front. Thought I didn't connect a hose or something. Have looked at every hose connection, checked radiator for signs of major leak, but can find nothing. Refilled it, drove it till hot, parked it, coolant still full, and not a drop coming out. So it seems at times (I believe twice so far since my work) that somewhere there's a large release within a short time frame. Think the first time happended right after parking as there was no antifreeze on the undercarriage, and then the second time whille driving since the antifreeze was everywhere.
Any ideas or siggestions?

2000 4.6 HSE
120k miles

 

possible air pocket leftin cooling system after your repairs, causing the coolant to escape past the pressure cap. ensure there is no air in the system and pressure test it as well as the cap.