FLYBOYJ
"THE GREAT GAZOO"
Never blown a hydraulic line at -40 have you Soren? This usually happens after the piece of equipment has sat for a while, like over night.
A 5606 hydraulic system can and will operate as low as -60F. If you're operating an aircraft that sat overnight and in -40 temps blow a hydraulic line, that tells me there was air or water entrapment.