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.
As the blood builds up in the atria, these valves open to allow blood to flow into the ventricles (the heart's two lower chambers). After a brief delay, as the ventricles begin to contract, the mitral and tricuspid valves shut tightly. This prevents blood from flowing back into the atria.eart valves can have three basic kinds of problems: regurgitation (re-GUR-jih-TA-shun), stenosis (ste-NO-sis), and atresia (a-TRE-ze-ah). Regurgitation, or backflow, occurs if a valve doesn't close tightly. Blood leaks back into the chambers rather than flowing forward through the heart or into an artery.