I believe there is a leaky valve that shuts the water on and off, Not the one on your house. Which you really should shut those off to. You would have to remove the top and back panel of the washer, remove the tub to be able to get to the pump and valve to replace valve or rubber washer. If possible, you should shut house water valves off that go to the washer. They also have little rubber seals inside that can wear out and leak.
Answers & Comments
I believe there is a leaky valve that shuts the water on and off, Not the one on your house. Which you really should shut those off to. You would have to remove the top and back panel of the washer, remove the tub to be able to get to the pump and valve to replace valve or rubber washer.
If possible, you should shut house water valves off that go to the washer. They also have little rubber seals inside that can wear out and leak.
If the back panel cannot be removed, than yes it is necessary.