I rebuilt the master and slave cylinders, assembled, and bench bled the whole system before installing in the car. The master cylinder didn't come with a reservoir seal. I keep getting air in the hydarulics, but I'm not losing any fluid. I'm wondering if it could be sucking it in around the reservoir seal. Anyone had any experience with this.

 

I've had a similar problem. I never did rebuild the bastards because of that exact reason you are going through. No leak but air getting in the system. I replaced my master cylinder and all is good.