It's hard to say without seeing the agreement, but you may be able to sue him for breaching the agreement. I would contact a local attorney. For one thing, it's hard to know -- from your presentation alone -- whether the agreement is enforceable.
Please see Section 17-1 (B) (2) of the attached link, below. The maker of the check has an obligation to make the funds good. You have a cause of action of the party does not make the check good. I also believe that the check 1) is evidence of a contract to pay, and 2) reopens the statute of limitations. You should contact a collections attorney.
If you choose, please select "helpful" or a "best" answer, below. LEGAL DISCLAIMER I am licensed to practice law in the State of Illinois and have an office in Kendall County, Illinois. However, I serve clients in many counties within the state of Illinois. My areas of practice involve Estate Planning (Trusts/Wills/Powers of Attorney/) and Probate, Business and Real Estate Counseling. Please take note that the above answer does not create an attorney/client relationship, and that all AVVO responses from both me and my attorney colleagues are for general legal education, only. Information obtained from AAVO or any other internet location should never be used as a substitute for competent legal advice from a licensed attorney that practices in your state. Please also be advised that the passage of time can often diminish the likelihood of success, and some matters will be barred by a Statute of Limitations. So, do not hesitate in seeking an attorney to specifically advise you. Finally, any reference to a specific law or theory of law is my best thought on the topic based upon a brief consideration of the topic, not a complete analysis of your specific situation. Best wishes as you seek resolution of your matter, and I hope you this answer helpful.
Possibly, you may have to prove that the passage of time serves as consideration in the claim to overcome the statute of limitations issue. You should speak with an attorney.