My upstairs bathroom sink is backing up and I'm not sure what to do about it. I removed the trap and cleared out a hair clog above the trap, put it back together and ran the water for a moment and the sink filled up and won't drain.

I ran a snake from the wall clear into the main and put it back together and still have no luck. I also got a pipe balloon (not sure the real name) and blasted water through the pipe. I can feel the water getting through, but as soon as I relieve the pressure and pull the balloon, I get about a quart of backwash. I'm sure I still have a partial blockage but I'm not having any luck. Any suggestions at this point would be greatly appreciated.

Thanks, Chris

Most likely when you ran the snake, it went in the horizontal for a few feet and then went up the vent instead of down the drain. If the bathroom sink has a dedicated vent that exits the roof, you can snake from the roof. Same thing with the water blatter, its just pushing water up the vent, then the water comes back out when you remove the blatter. This can be a tricky clog to get at if there are not cleanouts in the appropriate places. A little time with the snake and an extra ear for listinening to where the snake is going(up the vent, or down the drain) is about your best bet to start with.

If you can't get a snake down the drain or down the sink vent from the roof as suggested by MGD77 then you'll want to consider using a DROP HEAD on your cable machine... see image.

These drop heads have a tendency to drop the head so that the head is forced to go down the drain and not up the pipe. They don't always work if the blockage is really dense, but it's the next best bet here!

Otherwise, you need to the wall at the vent/drain junction or work in the attic to cut the vent pipe open and snake the drain from there. You would use shielded clamps to reconnect everything when done.

Good luck!

Mark