[Morris]

Fred

When we bench bleed the MC and we get all of the air out of the MC....then I remove the Reservoir and cap the MC input & the input with caps. Then we install the MC and when you hook up the lines ...yes there will be some air in the lines, so you have to bleed the system in the car....

If you don't bench bleed the MC.... and you install in the car .... there is a chance that you won't be able to get the air out of the Master Cylinder.... and the pedal will not pump up. Then you have to remove the MC and bench bleed it anyway.... Sol Bench bleed it prior to installation and then you know the pedal will pump up quickly ...and you can move the air out of the lines by bleeding the system... look at the photo's and you'll see the cap and plugs we use...just -3 & -4 Caps...
Hope this helps out.