When parking in a garage the other day I lost vacuum. Brakes went, no shut-off valve... It happened again today. Driving slow and hunting for a spot - pull up, reverse into spot - brakes stiffen, here comes a parked car towards me... Isn't there a vac. actuator of some sort on the tranny? Since this has never been a prob. at lights or in traffic, should I start with vac. connection to tranny?