Basically, just run the Pump Pressure Test.
Simplest way to get the pump ready is to fill a beaker with HPLC grade IPA. Place the 2 or 4 solvent pickup filters in it. Flush all Channels with pure DEGASSED IPA (either from your binary or quat pump). Make sure you take into account the channel volume of your degasser module for EACH line (either 1 ml or 12 mls, plus the volume inside each lp line too). Flush them all out, one at a time (not alternating) until each one is fully purged 100%. Next, select one channel, open the prime-purge valve and flush that channel, first at 5 ml/min to waste, then ramp down to 1 ml/min (a few minutes). You should get a steady flow out the waste port. Connect up a standards short stainless line to the prime-purge outlet port (e.g. 0.17 mm ID x 400 mm line). Point the line into a small glass beaker. While running at 1.00 ml/min, close the prime-purge valve and confirm the liquid is now emptying into the glass beaker. A steady flow should be observed and back pressure will probably be ~ 12 bars or so. This will confirm that the pump head is purged and ready for testing (seal break-in). Set flow to 0 ml/min, remove the short stainless line from the outlet port and replace with a SS plug fitting. Run the High Pressure Test. That will bring the system to max pressure (400 bars in your case) and hold it there for a few minutes while the pressure drop is monitored. This process is enough to break in the seals and confirm the system is pressure tight for use.
