1 Swap in a new set of shoes, reconnect the brackets & springs, put the drum back on and youâre done.  Thereâs no need for compressors, or opening fluid lines to retract pistons with these setups. As a matter of fact, replacing brake shoes on some vehicles can be accomplished in under 2 minutes, once the drum is removed.
The bicuspid valve, sometimes better known as the mitral valve, allows blood to flow in only one direction (assuming it is functional) from the left atrium to the left ventricle, it prevents blood from flowing back from the left ventricle into the left atrium.
Thus, the tricuspid valve serves as a trapdoor valve that allows blood to move only in one direction - from RA to RV. Similarly, the MITRAL valve (pronounced my-trull) allows blood to flow only from the left atrium to the left ventricle. Unlike the tricuspid valve, the mitral valve has only two leaflets. In the top diagram, you will also notice thin thread like structures attached to the edges of the mitral and tricuspid valves.