Genuine Advics Brake master cylinder. This master makes a great replacement for older Pickup’s and 4Runners with smaller bore size. Fits 1979-1995 Pickups and 4Runners. Master Cylinder features 1″ piston and residual valves for both front and rear disc brakes. Can be used with disc or drum brakes. Includes reservoir. This master cylinder is a must if you want to get full use of your rear disc brake conversion. We recommend upgrading your single diaphragm brake booster with our Dual diaphragm boosters found HERE.