Need some help here. Truck had been running all day with the A/C on... No problem. Stopped at the daycare to pick up my boy, left the truck running, was gone 5 min. Get back in start backing up and here a very loud "pop" opened up the hood and there is a a/c line connection in front of the radiator that had popped off losing all freon in the system. Reconnected the line. Went right back on put the clip on it. Now... What caused this? Should I try to put sone freon back in?? Is there a high pressure relief valve somewhere not working?? Sorry fir the long post just need some help as it's getting hotter in Texas.

 

It needs to be looked at to see 1-why the line came apart, and 2- there will be moisture and air inside the system now so it will have to be vacuumed. 3-there's a chance that alot of oil blew out of the system so refilling it without knowing if there is sufficient oil will leave you always wondering if the compressor will be starving for oil and self destruct.

 

I second that. They use "quick-connect" couplers that have a spring inside and require a special tool to remove, and with some it is an external clip holding it together, still faster to assemble than a threaded coupler (I assume that's why manufacturers use them).
While your AC system could have a bad high pressure relief valve, and something like the fan clutch getting weak or going bad may have caused the system to build up unusually high pressures at that time, overloading the holding force of the clip, the clip itself could have just failed. Some testing and diagnosis needs to be done before you fill'er up and go on.
I'd vac it down and fill it up, adding some oil for good measure, and run it in similar atmospheric conditions (temperature) to see what the pressure did, noting if the fan kicks in harder, then test by putting more air across the condenser. If the pressure do get very high, then look harder at the pressure relief to see if it is bad. If the pressures get up there, but not high enough to pop the high pressure relief, let's see if the fitting holds or blows again.
After all diagnosis and repair, if necessary, evacuate the system, replace the dryer/accumulator, then charge it again and be happy.

Chris