Determining service loads and safety factor of the elements from a brake system is very important aspect of
vehicles safety. Usually this is done by experimental testing of the elements, but not always all parameters can be measured
and all factors considered when the brake unit is assembled and in use. Because of this, the usage of MBS (Multi-body
Simulation) software is needed for simulating the working conditions and determining the loads of the system. The
analysis of the possible forces that load the elements of the slack adjuster from a brake system, the load distribution in the
slack adjuster and the use of verified model of a brake unit in SIMPACK in order to determine the service loads and safety
factor of the structurally weakest element is given in this paper.