How can I fix a toilet that's leaking out the back and side of the tank?

I just moved into a new apartment and I suddenly have a weird problem with my toilet. Whenever I flush the toilet, water starts leaking out the right side of the tank into the floor. It's like too much water is refilling the tank or something. The maintenance people in my apartment take forever and don't seem to be very competent. Is there a way I can fix this myself? Any ideas what might be wrong? Thanks in advance for any help you can give me.

I think I wasn't specific enough with the place of the leak. The water is coming out of the top of the lid of the tank and running down the side into the floor.

Take the lid off the tank and see what is happening. If the amount of water of a refill is actually overflowing the tank, then you need to adjust the device that regulates the level at which the water stops flowing. This could be a ball on the end of a metal arm in which case you may need to ajust a screw that changes the angle of the arm or you may need to bend the arm so the ball engages at a lower water level. If it is a float device that shuts off when it floats to a certain level, you need to adjust the clip that shuts off the flow when the float gets high enough. These are the two most common fixes. It all depends on what is inside your toilet.

If there is something wrong with the refill mechanism other than adjusting the fill level, then you probably shouldn't tackle that yourself. If you have no idea what you are doing, you could break the toilet or cause a flood, which would end up being very expensive problems.

The overflow tube should be allowing the water to flow into the bowl, even if the fill-valve is not shutting off. I would call the landlord and tell him damage is being caused by the leaking water. If you break something, the landlord will have no problem charging you for it.

Sounds like you need a new ballcock.
Video: how to:
http://www.metacafe.com/watch/458128/don...

Sounds like a flush valve that is in need of gut replacement.

Remove the lid & flush. The flush valve on the left side of the tank may shoot a blast of water up - it hits the tank lid & seeks its own level (meaning that your toilet may be just slightly off center & tilted to the right - but not so that you would notice).

If this is what is going on, the repair is a quick fix. The tool you will need is a phillips screw driver.

First, turn the water off at the angle stop & you may want to put a towel under it because it may drip a little - especially if it is old.
Confirm the water is off & drain the tank by flushing the toilet.

Second, unscrew the 3 screws on top of the flush valve & remove the disk like thing with the ball in the middle & the ring. Go down to the hardware store & get the replacement pieces (just a few dollars).

Third, put the pieces back in & put the top on & screw it down.
Be careful not to cross thread the screws & don't tighten one all the way then the others - do some on each till they are all tight.

Very slowly, turn the water back on & allow the tank to fill then flush it.

Hope this helps.

Depending on the mechanism in the back of the toilet it might be as easy as pulling up on the arm. If it's the old kind with a ball on the end of the wire, bend the wire up so the ball is higher. It should stop filling up sooner that way. If it's the new kind, you can adjust the chain where it meets the handle. Play around with it, adjusting it tighter until it stops overflowing.

The water shut off inside the tank is defective. Take the lid off and locate the float. It may be waterlogged. It is sup[posed to turn off the water at a certain height. Remove the float and drain it or replace it. If this doesn't fix it, then you need a new flush valve.