I have read past posts on this subject of people having rephasing trouble of master cylinder
1(When you do get all air out of wheel cylinders,, how do you know planter is level from side to side?
2( what is right height of bottom of frame bar to gound20, 21,22 Or 23 inches so center rows are not heavy downforce
Even germination with picket fence needs figuring out mistatakes, but weather nature is major factor