I just replaced the o-rings on my Moen 87780, and it still leaks. If I tighten the spout tight enough to not leak, it won't swivel. Just a slight loosening to allow the spout to swivel and the leak returns. What am I doing wrong?

SOURCE: I have a moen pull out kitchen faucet that leaks

You have a bad internal o-ring or the sprayer o-ring is leaking, if you look under the sink turn it off and then turn it back on, if you see it leaking out the center shft where the water pipes go into then the faucet may have a broken pipe or loose pipe. check and tell me where it's leaking at. You can buy kits to repiar them they are inexpensive.

SOURCE: Moen kitchen faucet model 7430 leak

cartridge does not stop that type of leak. If it is leaking from around the base of the spout it is o-rings that are the problem that are onthe valve after you pull the spout all the way off.

SOURCE: moen kitchen faucet spout

there should be a removable "button" on the faucet base below the handle. under there, there should be a set screw. loosen the screw, remove the handle. now u can adjust the base, collar, etc. to ur liking...don't forget to reassemble everything the same way u removed them.

Testimonial: "that was one reason I was looking for a diagram to show EXATLY how everything goes back !! will try your suggestion thanks"

SOURCE: Why would spout leak at the swivel?

The swivel base needs to be tightened. There is a gasket underneath.

SOURCE: How to fix a leaky Moen faucet that leaks at the

These faucets can leak in three different places:

1. Internally at the valve seat
   You'll see water dripping from the spout. This means the rubber washer is worn or damaged. To replace the washer, remove the decorative cap from the handle. Remove the retaining screw and pull off the handle. Remove the decorative cover, called an escutcheon, if there is one. Unscrew the packing nut counterclockwise. Unscrew the valve stem and remove it. Remove the screw that holds the rubber washer in place. Because these washers come in many shapes and sizes, you'll want to take the old one to the hardware store and buy an exact replacement. Be sure to buy two washers so you'll have one for the other valve. Replace the washer and reassemble the faucet.
   
2. Around the handle
   If you see water coming from below the handle, the packing nut is leaking. Older faucets have a string-like graphite packing material wrapped around the stem. Newer faucets use an O-ring. First try tightening the packing nut clockwise... about one-half turn. If this doesn't stop the leak, remove the packing nut and replace the packing or O-ring; then reassemble the faucet. If the valve is using the graphite packing material, it might be a clue that you should shop for a new faucet.
   
   
3. Between a pivoting spout and the body
   The spout might be held in place with a packing nut, similar to the faucet stem, or it might have a nut at the top of the spout. In either case, remove the spout and replace the packing material or the O-ring seal. Then reassemble the faucet.

Single lever faucets also are known as "washerless" faucets. They are easier to repair than compression faucets after you determine what type of faucet you have. There are three types of washerless faucets: ball, ceramic disk and cartridge.
Leaks are evident in two places... dripping from the spout and seeping from around the spout where it joins the body of the faucet.
Leaks from the spout indicate that the ball, disk or cartridge is leaking. To repair, turn off the water to the faucet, then remove the handle. The handles on ball-type faucets are held in place with a setscrew that requires an Allen wrench to loosen. Ceramic disk and cartridge-type handles usually are held in place by a screw hidden beneath a cap.
On ball and ceramic disk-type faucets, remove the ball or disk and replace the seals. You can buy replacement kits for these faucets at the hardware store or home center.
On cartridge-type faucets, remove the spout and pull out the retainer clip that holds the cartridge in place. To remove the cartridge, pull on the cartridge stem with a twisting motion. If it resists, install the handle so you can a better grip on the cartridge to pull it out. Take the cartridge to the hardware store or home center and purchase an exact replacement kit.
Reassemble the faucet according to directions.
Leaks at the spout-to-body joint indicate an O-ring failure. Disassemble the faucet as described above. Remove the spout sleeve and replace the O-rings. It's a good idea to replace these seals if you have the faucet disassembled for repair of the ball, disk or cartridge.