If you encounter a Nissan Quest/Mercury Villager minivan (up to the 2002 model year) with the left front brake locking up, see if the right rear brake is locking up as well. This vehicle has a component called a “dumping unit” that is screwed into one of the outlet ports of the master cylinder. The brake line for the left front and right rear brakes come out of this dumping unit. It has been common for the dumping unit to prevent brake fluid from returning back into the master cylinder.
Tags: Brakes, Minivan, Service bays, Technicians, Under-car service