upon arrival I found system low of refrigerant. I added 3 lbs of R410A. Then I leaked searched the airhandler and could jot find a leak anywhere. I removed condenser fan. Then checked everything outside. I could jot find a leak anywhere. I removed my hoses to check Schrader cores. I cleaned refrigerant sprayed my hoses and found both cores leaking. I tightened both cores and resprsyed with soap and water. I had no more bubbles. It is cooling at this time.