Is there a way to model a contact surface with mechinism or something else?

I have run into this on multiple occasions and I usually just find a work-around.  I have mechanism in an assembly, such as a pneumatic cylinder.  That mechanism is what drives another component until it reaches a contact with something else.  I don't want to change the distance of travel for that cylinder just so my upper assembly is more accurate.  Is there a way to model a contact surface using cam followers or something similar? 

Thank you in advance.