The Union Contract
Your boss's promises are temporary, a union contract is guaranteed.
Teamsters are covered by a union contract with the employer. Since every workplace and working conditions are slightly different, union contracts are tailored for each industry, shop, factory or other workplace. However, some basic things are the same. Contracts cover such rights and benefits as:
To win a good contract, workers must show management that they are united in support of their negotiating team. Sometimes workers have to get support from other unions, community groups, public officials, consumers, or other organizations to convince management to reach a reasonable agreement.
The rights and benefits in the contract are guaranteed. Management cannot legally change them without negotiating with the union.