R1234YF, Refrigerant, Enviro-Safe Stop Leak Sealant, Pro-Seal Charge Kit 4845

Even though Proseal for R1234YF can form a seal on the schrader valve, when you hook up to it the seal will release and allow you to use the schrader if necessary. If there is still Proseal for R1234YF in the system it will reseal the schrader.