Cilindro freno Iveco Zeta 109-14 (corretto)

Hello, a lot of time without going through here, I have a problem with one of the brake master cylinders, specifically that of the rear axle, these cylinders go along with their corresponding lung, said cylinder drip me, I am trying to look for spare parts, I get cylinders with different caliber, there is also no reference in the old cylinder, I have thought about disassembling the cylinder and measuring the internal gauge, but I would Mount it since I Devo lavorare con il camion e il ricambio richiede circa 10 giorni per arrivare. Ho detto prima che il mio camion è un Iveco Zeta (109-14)

Lo risolvo già, smontato il cilindro e il mezzo con il calibro, pedi il corrispondente e il funzionamento.