A failure is typically detected because the cycle time and the pressurization time is extended, causing a small leakage only. At worst, at a major failure, the tray may be filled by oil, but this is extremely unusual. The press will automatically decompress and evacuate the oil in the system to the tank. The operator can then close a manual valve at the main oil tank. A worn-out diaphragm is typically changed within four hours, having all replacement parts at hand.