I was changing my PTU fluid and read about others adding a hose to the vent tube and extending it up to near the brake booster, so they could use the drain plug on 2013+ and refill using the hose. I liked the idea, I could not reach the vent hose clamp so I took it to a place who extended the hose for me and changed the PTU lube with Amsoil severe duty 75-140 diff fluid. It used about half the
bottle.Here are points to consider.
With the car running you can hear alot of noise coming from the tube, even with the vent cap on.
There is a smell associated with the vent, venting diff lube smell, more noticeable when running and hot.
I took off my rear hood seal, bad move if you do this extension, the smell gets sucked into the cowl when heat or AC is on.
Makes it a 20 min job to empty and refill the PTU.
Cheap and easy to do.
May bend hose further behind firewall until needed to refill(making sure hose not get bent or crimped when heat hits hose, secure it properly).
(repost from other post on subject)