Jul 13, 2013     Braking system by Matco and Grove on our Sportsman - (50 hours)       Category: Brakes

The Sportsman braking system uses four Matco master cylinders. Each brake pedal, when tilted forward, applies the brake on left or right Grove brake calipers. The pilot and co-pilot brake pedals are connected to each other so either pilot or both can apply even or differential braking. Since the nose wheel freely swivels through a wide arc and is not directly connected to the brake pedals, using the brakes is necessary to help steer the plane when taxiing.

We ran into several trouble spots during the installation of the 4 master cylinders. The left co-pilot master cylinder had the brake line connections facing inward. In that position, they interfered with installing the center tunnel cover. So we reversed that cylinder and gained the clearance we needed. We mounted the reservoir for the brake fluid on the co-pilot's side to a bracket attached to the cage tubing. That position allows the viewing of the reservoir during the process of bleeding the brakes and making sure sufficient fluid is in the reservoir.

  May 15, 2013     Brake bleeding using pump oil can - (2 hours)       Category: Brakes

Bleeding of the left and right brakes independent systems is best done with two people. We bought a pump oil can on which we attached vinyl tubing which fit over the brake caliper bleeder nipple. The reservoir for the 5606 brake fluid we mounted on the right side of the cockpit under the instrument panel and attached to one of the cage tubes. The bleeding process entails pumping brake fluid back up from the wheel cylinder to the master cylinders, one attached to each brake pedal assembly, and up into the reservoir. We pump until we end up with the reservoir about 3/4 full to allow for fluid expansion.

  May 30, 2010     Parking brake system - (30 hours)       Category: Brakes

The parking brake system on a Sportsman is not mechanical but utilizes dual valves which "lock" the fluid pressure after both left and right brakes are held in the applied position. While pressing on the top of the rudder pedals, thus applying the brakes, the pilot pulls the Parking Brake knob out thus keeping the brake fluid from backing out of the wheel cylinders.