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? What is the major difference between the Airless Paint Sprayers and the HVLP Paint Sprayers? Is oiling needed for hedge trimmers? How to start an online warranty repair claim? The white plastic on the charging adapter has developed brown spots, is this normal? Comments 0 comments Please sign in to leave a comment.