i have a drain pipe in my basement that services my washing machine and kitchen sink (both upstairs)....I was running a load of laundry when the draining water backed up and came out the drainage pipe. my drain pipe runs across a wall and then attaches to the main drain under my cement basement floor. at approximately 9 feet from the connection of the washing machine and kitchen sink drain there is a seal with a trap at the top...it is here where water came out when the machine backed up. my house was built in the 1900s and has lead or galvinazed piping under the cement floor. I cannot open the trap at that first location of the water spurting out as it is not moving when I try. I used wd40 to try and help lubricate the top but to no avail. I was able to open another trap about 5 feet further down where I have an old soapstone sink. I snaked from there and pulled out a little debris. this trap is at an intersect of the under ground drain which continues on and then picks up the drain pipe from the bathrooms. I have snaked the pipe a few times only getting the debris once; i am assuming the snake is gioing to the left toward the washing machine piping. However I cant be certain. I tried running water through the system again and it again backed up and the first drain trap in the floor filled with water. how do i know if I in fact have a leaking pipe (it is covered in dirt and then cement) or if there is still a blockage causing that water to come out at the seal where the trap is.