Faucet is loose where it attaches to the counter

Brand of faucet or picture?

For a dual-handle Aquasource kitchen faucet with spray hose, the following instructions will afford replacement of the diverter. These instructions specifically refer to the faucet illustrated at http://pdf.lowes.com/installationguides/6953123900358_install.pdf, and the diverter identified as part RP70007 (item 14). Note the position of notches at the top of the diverter and around the rim of the base of the diverter, either of which can be used to leverage a tool to rotate the diverter out of position. Caution: The diverters on older faucets may be exceptionally brittle and thus very difficult to remove.

1. Using a pipe wrench or similar large-mouth wrench, unscrew the base of the faucet. Wrap the base with a cloth or other protective material to prevent scratching during the process of unscrewing. The base unscrews in a counter-clockwise direction.
2. With the base removed, remove the faucet. Note that a small amount of water may drain from the faucet when removed.
3. Removal of the base reveals the top of the diverter, which is a white, plastic cylinder approximately two inches long with copper stopper in the bottom. Insert a wide, flat-blade screwdriver across the notches in the top of the diverter - but be *extremely* careful. A faucet that has been installed for some length of time may have an exceptionally brittle diverter. If the upper shaft of the diverter breaks, a pair of needle-nose pliers may be used in the notches around the *base* of the diverter. Carefully rotate the diverter counter-clockwise to remove it.
4. Insert the new diverter and screw it into place in a clockwise direction. Apply a wide, flat blade across the notches in the top of the diverter to apply slight additional pressure to tighten the diverter just beyond hand-tightness.
5. Re-insert the faucet.
6. Screw the base back into position, tightening as necessary.
7. Test the operation of the diverter by operating the cold and/or hot water faucets, then the spray handle.

There should be screws that when tightened, will push against the metal flange that rests against the underside of the sink thereby pulling the faucet down and tightening it. Good luck!

On base of handle where it attaches to top of faucet, there is an access hole. It may be open or have a plug in it. If it has plug in it it just pops out with a little screwdriver. Under hole is either a allen head set screw or philips head. Loosen set screw then handle lifts upward. Try to tighten base of faucet if it is tight, you probably need faucet rebuild kit. Just make note of manufacturer. When at Home Depot,Lowes or other hardware or plumbing store compare price of kit to price of new faucet. Your decision which is less money or grief for you to buy or do.

http://www.needplumbingsupplies.com/Grohe-Kitchen-Sink-Faucets.asp?id=13758

This link has a spec sheet that will give you an view of under neath counter top. There should be a nut that you can tighten it up with.

Pull out sprayer has a plastic nut to tighten under countertop. You should be able to reach underneath and hold the top while tighting the bottom.

It designed to be tighten by hand to avoid damaging.

under the sink where faucet is unless lot of clearance use channel lock [adjustable pliers] or if like 99% only enough room for a couple of fingers you will need a basin wrench most hardware/home improvement stores carry it usually under $15 or ask around to borrow one that will get u up to faucet hold down nuts

there is a couple of plates with a little screw in the center that tightens up the plate got to tighten it up

I believe there is a cartrige that has some washers in the unit. There may be some debris caught in there since it was a little loose. I would turn the water off and disassymble the unit and replace any obvious washers and clean everthing up. Replace it all and try it again. If it still leaks, contact Grohe for more trouble shooting. Faucets have fantastic warranties and companies usually will send replacement parts free of charge at times. Hope this helps.

Here is the manufactures web where you may request the information you desire concerning your faucet.
http://www.groheamerica.com/s/25_4060/page/modules/iframe/index.php?if_url=http://12.130.64.173/litrequest2.htm