What kind of oil should be used to lubricate the check valve on the BLACK&DECKER Paint Sprayers? Support January 20, 2021 20:22 Updated Follow The recommended oil for the check valve is 3 in 1 oil. You can also use sewing machine oil. Related articles What type of oil should I use to lubricate the chain on my Alligator Lopper? Is oiling needed for hedge trimmers? How to start an online warranty repair claim? What is the major difference between the Airless Paint Sprayers and the HVLP Paint Sprayers? Can I buy Black and Decker parts online? Comments 0 comments Please sign in to leave a comment.