Sign disclaimer under duress to receive pay check

Just an incredible wealth of information here! THANK YOU!

Although... after reading the many situations here, I haven't found mine.

I worked for a company in Maryland as a skilled craftsman. The owner and I had a falling out over a job I refused to do, and fired me.

I asked for my final pay when I brought his supplied uniforms etc. back. He refused - saying that you return my items, then after everything checks out I'll mail your check.

If anyone is reading this - give any supplied material back immediately! It is criminal in MD to withhold it; I now know!

To the question I pose... I returned his items, and in order to get my paycheck he forced me to sign a disclaimer which he laser printed on the back that basically stated "By signing this check it constitutes full and final payment, no additional monies due to payee, and hold ___The Company____ harmless for any and all future actions"

I was required to sign a copy of that, or he would not release my check to me.
So, I signed the copy, but haven't cashed the check yet, awaiting your answer.

The check only covers a 2 week period - the 2 weeks prior to firing. I'm still owed additional pay, and expenses out of pocket, i.e. tolls, parking fees.

Additionally, I have recently found out from Maryland Labor Board, the company's practices of moving you around during the day from job to job must be compensated; wages paid. This amounted to a substantial amount of hours that I was never compensated for.

The company is a large national franchise (500+ franchisees), and they all operate the same way! Hugh suit! But, I'm only interested in getting my wages.

Question - If I cash the check with the disclaimer do I loose the rest of my wages, and the opportunity to sue for the additional hours that were bilked from the travel time going from job to job in the company supplied van?

I'd check the box that I would pay for a consultation, but I'd have to cash the check! Speedy reply would most certainly be appreciated