Here is what I do. Presta has no spring Schrader does and you must tighten the little nut down firm but only finger tight. I use adapters and my pump on the bike is set to Schrader. I leave the adapters on the Presta stem upside down and they act like a cap and protect the stem. I take them off open the stem nut and put the adapter back on with the rubber seal side to the tube. Pump up tire reading pressure on hand pump. When removing there is no chance of letting air out or bending the stem like there is using the Presta head alone. There is one pop of air and that’s the trapped air in the pump. Take off the adapter close the little nut hand tight and reverse the adapter and put it back on the stem till next time. I try and find the aluminum adapters in the fish bowl $1 at my LBS it’s full of about half aluminum half brass. Not that it matters but less weight haha and match my rims main reason.