My sink trap is leaking and I need to buy a new sink trap and/or washers.

But I’m not sure which one to buy, I’ve looked around and found the SA10 and SC10 but don’t know how to tell which one I have currently to replace it.

There is nothing on the pipe to indicate which one it is.

Can anyone help me with which one I need to buy to fix the leak?

Edit: there is a photo below with where the leak is coming from highlighted in red.

enter image description here

  • Forgive me I’m not the best at this sort of stuff, I suspect it’s the washers as there’s no crack or rust as the pipe is plastic. Is there anything I can do to help give more information?
    – UIO
    Nov 12, 2018 at 20:26
  • @isherwood I’ve also added a photo if this helps in anyway.
    – UIO
    Nov 12, 2018 at 20:35
  • @isherwood ah! I’ll try that! What if it doesn’t work? Just incase I need a back up plan. Washer replacement maybe?
    – UIO
    Nov 12, 2018 at 20:44

3 Answers 3


I'd just put a large pliers (channel lock) on that nut and snug it up. Clockwise from the top, assuming that the threads for that fitting are on the U-bend segment. Support the rest of the plumbing as you do so to prevent damage.

If that doesn't work, it looks like you have standard 1-1/2" (i.d.) plumbing there. Virtually any parts with the same configuration should be interchangeable.

  • I’ve looked around at a few replacement parts and there are 1 1/4” and 1 1/2” ones, how will I know which is right should I have to buy a replacement?
    – UIO
    Nov 12, 2018 at 20:47
  • A tape measure is a good starting point. Since your trap appears to be the same size as the welded PVC behind it, it's a safe bet that it's not 1-1/4". That almost always terminates in a reducer at the welded plumbing. It's also typically only used for bath sinks.
    – isherwood
    Nov 12, 2018 at 20:49
  • Which part do I measure the pipe width or joint part width?
    – UIO
    Nov 12, 2018 at 20:52
  • The diameter of a typical pipe section, not a wider bell end.
    – isherwood
    Nov 12, 2018 at 20:55
  • 7
    A very good piece of advice would be to take part of the existing piping with you to the store if you are uncertain as to details of its size, thread, nut and washer compatibility.
    – Michael Karas
    Nov 12, 2018 at 21:16

I would unscrew the nut and put a little silicone caulking on the plastic washer that will be exposed. Then re-tighten the nut and let sit for a few hours. AS for drain sizes; Most kitchen sinks and laundry sinks, use 1 1/2" drains and bathroom sinks usually use 1 1/4" drains. Yours is 1 1/2".You can buy replacements at any big box store or hardware store, home centers etc.

  • 2
    I'd avoid the silicone. It's a quick/easy fix but when I've discovered this and needed to do any kind of repair it becomes a hassle. A course "little" is the key term. Seems I always run into the "little" equals "a lot" scenarios. Nov 13, 2018 at 13:57

Can't see what's going on to the right of the trap?...The whole set up looks like it needs repiped...just saying. That trap isn't bad, I mean it serves its purpose but changing it to a slip nut type would mean redoing the coontinous waste and other pieces...take some good, complete pics, maybe be even take a pic that shows nside bottom of sink...underside, get from both sides and show outlet side where it all ends up...trust me, you can do this. Take the pocs into a Lowes or mennards and they will hook you up. Grab an extra slip nut or 2, extra washers, tailpiece washer for each basket strainer. Can't tell wheteher you have disposal or not...if so you might as well grab long tailpiece or buy a disposal drain kit? Heck, for a buck or to buy an extra tailpiec (all plastic parts and pieces here)...they sell a double ended tailpiece that may give you some extra insurance? Either way, clean all that stuff up or you'll be chasing leaks all the time...

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.