When changing transaction data in a block change the hash of previous block? If i only manually change the data on the block without touching/modifing the already calculated hash, then hash on the block its still valid because its already saved and was not touched ... so,  

When the blockchain revalidate the hash with the content of the block? ... 

In every paper that i read i see that all the security and inmutability of the blockchain its based on the already calculated hash, so, its like its easy to change data without touching hash so block still be valid in all the merkle tree and chain... how this modification its protected?
When a new block is received by a node, it is validated. This validation includes verifying the validity of each individual transaction, constructing the merkle tree and the merkle root, verifying the merkle root against the block header, verifying the PoW in the block header, and finally verifying the hash itself.

After this validation is completed, the block is saved into the node's local chain database.

If you were to go and modify the stored data, it would have little effect - no other nodes will see your modified data, and all you will achieve is a broken local state if you run a reindex or reindex-chainstate.