As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CRUISING AT FL 370. THE RT PACK WOULD CYCLE OFF & ON. DESCENDED TO FL 310 & THE ISSUE CONTINUED. WE NOTICED THAT THE RT BLEED PSI FLUCTUATE, BETWEEN 49 & 29, WHILE THE PACK WAS ON. R & R RT PRSOV. OPERATIONS & LEAK CHECKED GOOD IAW AMM 36-12-01.