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.
Each chamber has a sort of one-way valve at its exit that prevents blood from flowing backwards. When each chamber contracts, the valve at its exit opens. When it is finished contracting, the valve closes so that blood does not flow backwards. 1  The tricuspid valve is at the exit of the right atrium. 2  The pulmonary valve is at the exit of the right ventricle. 3  The mitral valve is at the exit of the left atrium.