Ok I guess I didnt fill the whole thing out so here goes...

we returned after a weeks vacation to a soaked floor and the washer tub full of water and overflowing even though it was shut off !!

I also had the main water turned off. Now someone told me the ONLY way this could have happened is IF the main didnt shut off tight and the inlet valve stck or is bad,,,true ?

1) if so do I replace the valve or could it have been a fluke ??
2) if i have the main turned on so there is full pressure and the washer off would it fill the tub IF the valve is bad or is it only do it under low pressure ??
3) if the valve does need replacing how do I geth the top off the washer to get at it ??
4) and I probably should replace the washer in the main house shutoff or should I just install a ball shut off above this 50 yr old screw type shut off ?

pls help...thx