Meal. I have a question about the four-circuit protection valve on an IVECO Turbozeta 65-12 Bj 88 The chassis has a RV body 3 pressure vessels and a mechanical hand brake. The structure has a staircase which is operated with a compressed air cylinder. This cylinder is slightly leaking, which is actually not further tragic. However, of course the pressure in the auxiliary circuit decreases slowly and the stairs no longer go in and out. Also no problem. uck in the brake circle 1 and 2 slowly drops down to zero. Therefore, I always have to wait before shunting until the compressor has refilled the containers because otherwise I am travelling completely without a brake(only hand brake) Before the warning lamps of the brake circles extinguish the stairs but already compressed air again. So, in my opinion, a small pressure loss in the auxiliary circle must not lead to the storage containers of the brake also become pressureless. 2. I only know it this way, the K journey 1+2 and then the handbrake and auxiliary circles How do you see this? Protection valve leaks internally? Greeting Jürgen