heres a little trick we use on the motorcycles

if you have a decently hard lever, but still think there might be air, zip tie your lever in to the bar(like you were pulling the brakes) and bounce the bike a little, then leave it over night. you open the system up and it should allow any air to move back to the top of the reservoir and out of the system

there is no telling how long your lever will last as hard how you have it now, the problem being there is a small ammount of air in the system, and you have most of it out, the biggest issue is when it gets hot, the air will expand giving you little to no braking power, but the likelyhood of this happening is pretty rare.