Bleeding Mazda B3000 clutch Master cylinder

I have a 2002 B3000 with 58000 miles. The slave cylinder started leaking and I took it to a very well trusted transmission shop because I do not have the jack to replace at home. BTW, I am a ASE master certified tech. Anyhow. They replaced the slave cylinder, and it was indeed leaking. However, they cannot keep clutch pressure, but no fluid loss. They replaced the clutch master cylinder and they can get pressure for a while, not much longer. Now all parts have been replaced, same result, no clutch pressure after sitting a while.

They checkd with the ATRA, and they acknowledged there is a bitch of a deal bleeding the system, however, their senior technician at the shop of 26 years (I know he is a master rebuilder), he could not get it to hold a pressure. Trust me, he is the only lasting technician I have ever trusted with all transmissions!

I hold them harmless, cause I know crap happens. However, to assist them, I am wondering what is up? Is there some special procedure to bleed this 2wd "Ford" pickup?