▁it ▁is ▁also ▁possible ▁to ▁briefly ▁" over load " ▁the ▁bra king ▁system ▁to ▁a ▁pressure ▁proportional ▁to ▁the ▁de pression ▁previously ▁present , ▁up ▁to ▁a ▁maximum ▁pressure ▁of ▁; ▁shortly ▁after ▁this , ▁the ▁pressure ▁dro ps ▁to ▁, ▁and ▁is ▁gradually ▁brought ▁back ▁to ▁ ▁in ▁about ▁ 2 4 0 ▁se cs . ▁ ▁However , ▁on ▁units ▁with ▁Tri ple ▁Val ves ▁( Dist rib ut ore ▁tipo ▁West ing house ) ▁and ▁ 7 - position ▁le vers , ▁bra king ▁circuit ▁is ▁slightly ▁different . ▁The ▁ ▁is ▁divided ▁in ▁two ▁parts ▁like ▁said ▁before , ▁but ▁there ▁isn ' t ▁the ▁command ▁res er voir ▁tank : ▁when ▁the ▁pressure ▁inside ▁the ▁bra ke ▁pipe ▁dro ps , ▁it ' s ▁directly ▁the ▁auxili ary ▁res er voir ▁that ▁makes ▁the ▁frame ▁put ▁in ▁the ▁middle ▁moving . ▁▁ ▁B rak ing ▁is ▁not ▁grad ual ▁on ▁release ▁in ▁this ▁case : ▁when ▁the ▁driver ▁puts ▁the ▁controller ▁on ▁" release " ▁position , ▁bra kes ▁are ▁fully ▁released ; ▁if ▁he ▁bra kes ▁again ▁too ▁shortly ▁after , ▁there ▁is ▁the ▁risk ▁to ▁have ▁a ▁loss ▁of ▁bra king ▁power ▁because ▁there ▁may ▁not ▁be ▁enough ▁air ▁to ▁bra ke ▁optim ally , ▁since ▁the ▁absence ▁of ▁the ▁fixed ▁pressure ▁of ▁the ▁command ▁res er voir ▁doesn ' t ▁ensure ▁that ▁there ▁is ▁enough ▁air ▁to ▁safely ▁release ▁the ▁bra kes . ▁It ▁is ▁even ▁possible ▁to ▁fully ▁exhaust ▁the ▁res er voir