A number of months ago, I hit a deer while riding a 2018 Triumph Street Triple R (motorcycle).
Since then, the motorcycle frequently drops a significant amount of coolant out the coolant waste tube, until the amount of coolant (with a cold engine) is well below the "low" mark, and the reservoir is nearly empty.
If I leave the engine running, I can watch the fans kick on and the coolant level in the radiator move between the low and high marks on the coolant reservoir.
The problem, is the amount of coolant moves significantly above and below the low and high marks on the reservoir. When it is at its low value, the coolant level is significantly below the low, or cold mark on the reservoir. When the coolant re-pools into the reservoir, it goes significantly above the high mark. It will then eject a bunch of coolant out the waste tube, and on the next cycle, the coolant in the reservoir at the low point will be almost empty.
I recently replaced the radiator, and the new radiator came with a new radiator pressure release cap.
I'm not sure what else I should check? All of the hoses seem normal, and the engine never overheats.