For 1990-2009 cars

Causes | Correction
--- | ---
Leaking brake pipe/connection | Locate and fix the brake pipe/connection.
Leaking caliper piston seal | Replace the caliper piston seal.
Leaking master cylinder (internally) | Repair/replace the master cylinder.
Leaking rear wheel cylinder | Repair/replace the rear wheel cylinder.
Leaking proportioning valve | Replace the proportioning valve.
Restricted passage in vacuum booster | Replace the vacuum booster.
Damaged vacuum booster | Replace the vacuum booster.
Restricted brake fluid passage | Locate and fix the brake fluid passage restriction.
Improper rear brake adjustment | Adjust the rear brake linings.