We're new to these pumps but that may be what is happening. Pumps fine and you can feel the air in the mainline part way up it but it's not pulling the sap from the laterals like our other pump is in the other bush. Also have a new 4008 coming to try a different pump.
305 taps on 2 Shurflo's, 31 taps on 3/16" and 229 taps on gravity. 565 in all
Mountain Maple S3 controller for 145 of the vacuum taps
2x6 Darveau Mystique Oil Fired Evaporator w/ Smoky Lake Simplicity Auto Draw
Wesfab 7” filter press