My family and I just returned from a 600 mile round trip fishing/camping trip to the Eastern Sierras towing my 35' 5th wheel with my 04 F350. On the way up we were about 50 miles out of Ridgecrest in the middle of bumfucnowhere when I noticed water on the windshield, the smell of antifreeze and an climbing water temp gauge. I pulled over and popped the hood anticipating that my coolant filter kit was leaking somewhere but instead found that the degas bottle cap was gone and coolant was boiling out all over the place. I searched around the engine compartment to no avail and was about to call AAA when I looke again and found the cap stuck between the battery and driver's side headlight. I added about 3 gallons of water, put the cap back on and wrapped some duct tape around it for good measure. We finished the trip with no further issues but now I need to flush the coolant system and refill it with new 50/50.

While I haven't heard of this issue previously, do the degas caps have a history of coming loose on their own and blowing off or did I not tighten it enough (even though I'm 99% sure I did) when I installed the coolant filter and topped the system off? Just for the record, the degas bottle and cap is only about 3 months old as it was replaced by Ford when my truck was in for the EGR cooler and engine oil cooler work recently Any other ideas or thoughts? Thanks.

By the way, the trout fishing was great and the weather beautiful (and the NAPA Autoparts store in Bishop carries Zerex G05 Coolant) but the "what next" feeling and clenched fists every time I take a trip somewhere is getting old

 

Only you can answer, did I tighten it enough? You do have to tighten it till it clicks if you don't know that. I'm heading up there Monday. 1 week at creekside and 1 week at McGee Creek.

 

Well, it's was probably one of three things then; either I left it off completely (not plausible as I should have had problems way sooner than 200 miles into my trip) or I didn't tighten it all the way, although I do know that when it clicks it's tight. It may also be cracked which allowed it to loosen on it own but I'll have to look further into that. Only time will tell once I flush the system and put it all back together. Thanks and enjoy your trip.