"bkcham85" wrote in message
The sewage
backup seems to happen when the clothes washer is draining and
somebody is flushing the toilet or taking a shower at the same time.
Anybody have any ideas?? Thanks.

Yes, there is still a partial blockage somewhere past the cleanout since
that is leaking also. . Maybe old, maybe new, but it is definitely blocking
up. If not in your line, it is in the main line.