| Pressure in the line | Possible reason |
| Low pressure only in situation D | Malfunction of hydraulic system for situation D |
| Low pressure only in situation R | Malfunction of hydraulic system for situation R |
| Low pressure only in provisions D and S | Jamming of the valve of regulation of pressure |
| Misoperation of the primary adjusting valve |
| Wear of the oil pump |
| Malfunction of the hydraulic line of a brake of lowering transfer |
| Pressure is higher than the specified | Jamming of the valve of regulation of pressure |
| Misoperation of the primary adjusting valve |