How can u tell if your motors benn damaged from a timing belt brake while driving?

You should be able to tell, just by removing the valve covers as opposed to the cylinder heads. After the cover is off, you should see one or more of the valves sticking up and be able to tell if they are chipped, scored or bent, with out pulling the head and looking at the underside of it. Also, with the belt snapped off, you should be able to rotate the camshaft pulleys by hand or with a wrench to see if they rotate smoothly or if something is bent or broken. Unfortunately f it is an interference type engine, you will no doubt have to replace the heads or have them rebuilt.