Q: Replaced calipers and brake shoes. Bled the brakes and loose clutch. Get clutch back and loose brake pressure. Why?

Hello. The symptoms you are describing are very unusual. The clutch and brake hydraulic systems on your vehicle are separate, and should function completely independently of each other. The brake master cylinder uses a completely different set of lines than the clutch master cylinder does. I would try carefully bleeding both systems once more, just to be sure that there is no air in either system.

If both are bled properly, I would then move on to making sure that none of the components of either system are leaking. Leaks at the master or slave cylinders, or at any of the calipers or wheel cylinders will cause the systems to lose pressure. If the problem persists, I would then consider the possibility of a defective master cylinder.