Mazda B4000 owners have reported 2 problems related to brake hoses, lines/piping, and fittings (under the service brakes category). The most recently reported issues are listed below.
The right front brake line on the truck ruptured during breaking. Luckily this happened in a parking lot, so there was no damage or injuries.
See all problems of the 2003 Mazda B4000.
Metal brake line failed in engine compartment leading to a complete loss of all brake fluid and braking. One brake line corroded through, another line was severely corroded, and the 3rd line is just starting to corrode. There was no warning of any problem.
See all problems of the 1996 Mazda B4000.