As I wrote in #12, "This is what you need: McMaster Carr 5269K311 METRIC STEEL COMPRESSION TUBE FITTING, ADAPTER FOR 6 MM TUBE OD X 1/8" NPT MALE PIPE"

The injector hard line mates right up to the compression side of the adapter; the other side is male 1/8 pipe thread; add whatever other fittings you need, to get from there to your pump. I got an old porta-power pump like they use in body shops; works great. Be sure to get hydraulic fittings not just brass fittings -- the pop tester will develop a lot of pressure and I hear that it's enough to blow out regular brass fittings. The McMaster Carr site is a good source for specialized hardware like this.