CTIS Leaking and front only fills to 32psi

[2002H1]

My CTIS system leaks about 15psi in the front overnight and the back 5 psi. I heard the front could be the "blow out valve" and I dont know where to begin. This all came about after Predator put custom rims and tires with their quick release system. They said there was a leak in the front connector and they claim they fixed it. Any ideas of what it could be, and how much psi should this system leak as they claim it is typical to leak?