I'm not sure what size the o-ring is......you might just have to take it off and take it to a parts store to match it. Hopefully it's just the bypass hose and you won't have to worry about the o-ring on that hard line. if you lost a LOT of coolant, then that line going into the water pump is probably not the problem. Usually that's just a slow seep.
Yes, this is my truck. No, I won't help you move.
Current: 2015 1500 Ecodiesel, outdoorsman, crew cab, leveled with Bilsteins
Sold: 2013 Ram 1500 CC, Flame Red, Outdoorsman, 6-spd, 3:55s, BT Catch Can, TonnoPro Loroll tonneau, 26% front tint, Bilsteins @ 2.1, Mevotech UCAs, AirLift 1000's, plasti dipped badges, wheels an bumpers, Amsoil
Sold: '07 Ram 1500, 295/70/18 Nitto Terra Grapplers, American Racing ATX, K&N Cold Air, true duals, ProCote bedliner, 6" lift, Firestone Air-ride Suspension Helper Springs, Bilstein 5100s, Pioneer navigation unit, AMSOIL, 190 t-stat, 1-ton transmission cooler, Transgo, 4.10 with Auburn LSD, Superchips
Sold: '07 Ram 1500 Mega Cab, 5.7l Hemi, AirRait AIT intake, AMSOIL, Hellas behind the grill, block heater, Transgo HD2 shift kit, B&W gooseneck hitch, Magnaflow 4" stainless exhaust, 2" leveling kit, Bilstein 5100s
Sold: '99 Ram 2500, 5.9l 360, NV4500 Tranny, AMSOIL, 180 T-stat, MOPAR Performance open element, home ported TB, plenum fixed, 2" leveling kit + Bilstein 5100's, 295/75/16 BFG AT KO's on black RockCrawler steelies, Magnaflow high-flow cat and muffler, 3" single in/out, smoked cab lights, luke's links, lights, lights, lights