I had the valve replaced about 4 yrs ago - the plummer put one with a clear knob on it-its leaking terrible - losing about a gallon of water every 2 hrs or so - I don't know how to get the clear knob off to tighten it - don't want to chance breaking something.:mad:

Also, SO glad to find this site - this is a three generation - female household! We lost my Dad a year ago February 27th and he was out "I'll tell you how - you do it"! Man.

First SHUT OFF THE WATER so you don't have any water damage to your floors.

If that particular shut off valve is leaking and you're a female may I suggest that you invest in a Mrs. Fix It Yourself book as well? I have 4 different ones all from the 1980's and 1990's. Nothing much has changed since then in plumbing or appliance repair. I bought mine on Amazon for about $1 each plus shipping. Well worth it as I consult them regularly. One is a Reader's Digest and another is Time Life. Those two are like GOLD, believe me.

In the meantime, here is a link that should help you out. Just be sure you use white plumbers Teflon tape (about $2 a roll) and wrap the pipe threads twice around with it before connecting back up.

Fix A Leaking Shutoff Valve | Electrical & Plumbing | Reader's Digest

I tried that. I think the screw in the end at the knob to turn it on and off needs to be tightened. However on the valve the plummber put on there is a clear plastic cover with no hole to get a screw driver through - I don't know how to get it off for fear of breaking something. Searched the net and couldn't find any mention of the knob cover.

Barbie... the clear handle should have nothing to do with leak. The leak is at the packing nut just behind the clear handle. Look closely and you will see that the metal stem goes through the nut and into the valve. This packing nut is meant to be tightened.

Here, hold the valve body in 1 hand and tighten packing nut with a pair of pliers... start with a 1/4 turn... no more to start. Look at picture. That should do it... let me know.

If it does not do it then you may need to wrap teflon tape around stem.. OR graphite rope (sold at supply stores) and then retighten packing nut.

Worst case... time to replace... but that is a last resort , of course.