Its a lever, not separate knobs. It is loose and wiggles. I have to play with it to get the faucet to stop dripping.
I tried an allen wrench. The one that fits in the whole doesn’t turn. It just gets stuck. What should I do?
The handle it not tight, that is the problem. I tried an allen wrench after reading Earl’s answer and it didn’t work. The allen wrench gets stuck and the handle doesn’t tighten. What else should I try? Could I need a new screw?

Need help ASAP….We have a Delta Single Lever faucet in our kitchen that as of yesterday lost water pressure. It has an aerator built into our PUR filter which I removed to check if that was the problem. There was some sediment built up, but with the entire filter and aerator removed there is still no pressure. Every other line in the house, including the bathroom toilet and sink in the next room over function perfectly. Can anyone suggest where I can look next to possibly fix this problem?
Checked the valves under the sink….doesn’t seem to be a problem there.
As far as a cartridge is concerned, I am not quite sure there is one….when I removed the housing I found the metal ball beneath the cam and the support springs (which all seemed fine). I am in the middle of trying to run a thin plumber’s snake through each side (hot and cold) but it makes little sense that I should lose water pressure on both lines, right?
Okay….under last suggestion pulled up spout and found diverter…how do I know if it is stuck and if stuck how do I make it unstuck? It does look like there is a build up of sorts so should I use a cleansing agent (like CLR) to brush it up?
New development…
Checked diverter….found some strange black stuff (rocks? rubber?) blocking its movement. Removed the blockage. Went back and reassembled faucet by the letter…springs and all…turned water back to full open on both valves and used the top of the faucet ball to turn on water…water came out full blast and let it run for two minutes to be sure…reattached lever handle (had some trouble here) but turned water on again and the pressure went for about ten seconds before disappearing altogether…barely a dribble. Went back and checked for blockage at diverter again and none found. Followed steps back to reassemply and got pressure for ten seconds before it seemed as though lever (or something inside it/beneath it) came loose again and pressure left. I know I have tightened everything properly so where could the problem be? The lever AND the diverter maybe?

The faucet at the kitchen sink is a single lever type where you move it left or right to change temp and up and down for on/off. When using the hot water side it randomly goes to 1/2 pressure and there is a simultaneous water hammer bump from the back of the house. Is there a water blending valve in the faucet that may be going bad or should I look elsewhere? I have drained the water pipes througtout the house already by turning off the main valve and openning all the faucets in the house. I then closed all the faucets and turned the water back on. At that point I then turned on all of the faucets to bleed them. Make sense?

My water pressure was perfect a month ago. All of a sudden it just lost pressure. Over the course of the month, I have lost all water flowing through my kitchen sink and almost all my other faucets. My kitchen sink, with both levers turned completely open, only drips. My bathtub now, looks like my kitchen sink should. I have looked online and cleaned every aerator. None of these were solutions to the problem. WHAT HAPPENED?!? I’m clueless. I also drained my water heater. While there was sediment, after I finished, there seemed to be no difference.

Today I hooked up a reverse osmosis filter to my sink. I only use it occasionally to fill up my aquarium so I unscrewed the spray hose, and screwed in the input hose for the filter to receive water. When I disconnected it and put the normal attachment back on, I noticed that water was streaming from the back of my faucet through a tiny hole that would appear to be a relief outlet or something (it has the letters C-L below it).

The faucet is a Kohler, the type where you have one lever that controls both temperature and force of water. What is causing this leakage and how do I get it to stop? I have tried to run the water to see if it was pressure related, I have tried turning the faucet and nothing seems to make it stop. HELP!

It is my kitchen sink. There is a constant drip coming from the spout. It has just one lever that is pulled up to turn the faucet on… and then swiveled to adjust temperature. Here is a picture of the style. Mine is much older.

http://www.ritz-craft.com/Images/67425_single_lever.gif

I have tried purging the air bubble several times by shutting the water main and then letting all faucets run for 15 minutes. I still get "knocking" thereafter when I quickly shut the kitchen one-lever style faucet (hot water-side only). I installed 2 screw-on mini hammer arrestors to the washing machine, but they aren’t doing the trick.

price fister single lever faucet control is loose and have to move it around to stop dripping or running. How do you take the lever control off the top of the faucet?

I have a Moen single lever faucet in the kitchen. It has had a steady drip for a while now, so I figure it may need a new cartridge. I removed the handle just to get an idea of what I’d be working on and then put the handle back on. The handle will now move up as normal to turn water on, but it won’t move back down. I have to press down at the base above the valve to shut water off. I’m sure I put the handle back on correctly because it only fits over the valve one way and has a single screw. Any ideas what’s wrong?