My bathroom faucet is dripping, and I would like to change the washers in it. The problem I am running into is the placement of the nuts holding the faucet valves in place:

underside of sink

This is the underside of the sink, the hot and cold valves are on either side. The nuts holding the valves in are quite large, and they are inside a small recessed space that I can barely fit a small pliers into, much less one large enough to actually get around those nuts. Does anyone have any suggestions for how I might get those nuts off?

Update: Always make sure you are asking the right question first, see answer below. Though if anyone is in a similar situation to mine and actually needs to remove a valve, some of the other suggestions here look helpful.

  • 1
    Did you try using your fingers? Sometimes these are simply finger tight, with possibly a thin layer of sealant acting as a compression washer. A bit of wiggling may be all that is required.
    – Criggie
    Commented Dec 9, 2019 at 10:53
  • Far as I can see, it IS on flexibles. See the silver thing halfway down the RHS of the photo? That's a flexible connecting to a 6-inch copper stub. The two valves are blind -- they take in on the copper stubs and out through the plastic. Two plastics feed into the central fitting, which is probably a swivel mixer outlet with a waste remote lever running through it. In which case, the copper tails are welded into the valves, but the securing nuts are bit enough to go over the tails completely. Commented Dec 10, 2019 at 13:32

4 Answers 4


Maybe I'm missing something here but why are you trying to take off those nuts? The washers for the valves are topside. You just have to remove the valve stems to expose and change the washers. If you wanted to replace the faucet, then you'd need to get these nuts off.

  • If there's a way to get to the washers without removing these, great. The valve handles don't seem to be removable from the top though. Commented Dec 8, 2019 at 21:18
  • On closer inspection, you are correct. The valve handles are removable, just in a non-obvious way. I think I still need to get a basin wrench or similar though, because the nut on the top of the valve assembly is rusted on, and turning it just turns the whole valve, so I still need a way to hold it from the bottom. Commented Dec 8, 2019 at 21:32
  • 7
    Try grabbing the valve body with your channel locks and use an adjustable wench for the nut.
    – JACK
    Commented Dec 8, 2019 at 21:39
  • 3
    That is exactly what I needed to do. Thank you @JACK for saving me a lot of unnecessary effort! Commented Dec 8, 2019 at 21:54
  • Actually, one good reason to remove the whole faucet to change the washer assembly is that it is usually corroded in, or cranked way too tight by some previous repair. Undoing it in situ risks turning the faucet (which often has a square section) in the hole in the sink, which can crack the sink or kink the copper below. I prefer to get the whole faucet clamped in a workbench before I get heavy-handed. It means you don't have to work in a confined space, or drop small parts down the drainage, and you can use heat on the beast or soak it in paraffin overnight. Commented Dec 9, 2019 at 17:36

This is exactly the purpose of a basin wrench

basin wrench

Here's a picture from familyhandyman.com that shows a basin wrench in action:

basin wrench

Note that as mentioned in another answer, you usually don't need to remove the faucet to replace the washers; but if you do need to remove the faucet for whatever reason - this is the tool.

  • 1
    I almost had the opportunity to post my first picture (of a basin wrench) on StackExchange, but batsplatsterson beat me to it.
    – user116960
    Commented Dec 9, 2019 at 23:09
  • I think that this answer could be improved with an explanation of how to use it to do so, because I'm looking at the picture and I'm not sure how it works.
    – nick012000
    Commented Dec 10, 2019 at 5:34
  • The chrome bit goes vertically up behind the sink. The black jaws are self-tightening (like a Stillson wrench) and go either side of the nut. The joint between the two part swivels, so the jaws can face either clockwish or anti-clockwise on the nut, so you can both loosen and tighten with it. You can hold the top part in place with one hand to get it started, and put a box spanner or similar tube over the lower handle to get extra leverage. Commented Dec 10, 2019 at 13:16
  • 1
    There are also specific socket wrenches that performs this task well (the size of the nut is standard, so you only need the one - usually) - google "faucet socket wrench" for a variety of examples.
    – Stian
    Commented Dec 10, 2019 at 15:02
  • 1
    Just be sure to refresh your supply of expletives before you start using the wrench.
    – Hot Licks
    Commented Dec 11, 2019 at 20:28

I usually remove both of the supply pipes then make a socket to fit from a suitable sized metal pipe.

Even found a copper pipe hammered on was sufficient in some cases.

  • Yes, if you can remove the supply pipes in situ. From the picture it looks as if one of them is copper, not a flexible connector, and as if somebody has sealed them into place on the faucet with silicone or putty. The right way to do these is to make sure there are service valves, flexible connectors from the service valve up to the monobloc faucet, and absolutely nothing except the little o-ring sealing the flexible connector onto the faucet. You just do it up finger-tight, the o-ring is the seal, and it can't come un-done once the flexible connector is attached to the service valve.
    – nigel222
    Commented Dec 10, 2019 at 10:58
  • @nigel222 those o-rings usually go into the body to give a good seal, the threads are set a bit lower to give the o-ring a sealing surface.
    – Solar Mike
    Commented Dec 10, 2019 at 11:03
  • Yes, that's my point. I recently spent a long time in an under-sink cupboard re-plumbing and replacing a faucet, made far harder because whoever first installed it had "glued" the connectors into the faucet body, and had used neither flexible connectors nor service valves (so I had to shut off hot and cold water to the entire house). Sigh. Done right you just unscrew the flexi connectors from the service valves, then from the faucet, and then it's easy to unscrew the big nut holding the faucet to the work-top.
    – nigel222
    Commented Dec 10, 2019 at 11:08
  • @nigel222 I always fit service valves... but the question from the OP was not about service valves - it was about how to get the large nut undone and that was what I answered in my answer. If you want to post a new question about plumbing and good practice then you should do so.
    – Solar Mike
    Commented Dec 10, 2019 at 11:45
  • I commented, because while the OP had the faucet removed (if he needed to) he should remediate that plumbing. Also because if I'm right and those connectors are glued in, and if it's not a simple matter of replacing rubber washers from the top, then he's quite likely going to have to replace the faucet (as I did).
    – nigel222
    Commented Dec 10, 2019 at 11:54

A crowfoot wrench might do it, if you can find one that's the right size to fit those nuts.

Another option (much more work) is to disconnect the pipes lower down (where they join the hard lines), disconnect the drain, and pull up the whole sink.

enter image description here

  • 2
    Also, are you sure you have to remove these nuts? Usually, when a faucet is dripping, the first thing to do is remove the faucet core, which is normally done from the top, not the bottom. Commented Dec 8, 2019 at 20:58
  • 3
    Mike, the first thing I like to do is shut off the water pressure under the sink (or at the mains for a larger job).
    – user109695
    Commented Dec 8, 2019 at 22:00

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