How To Repair A Leaking Mansfield Toilet

How To Repair A Leaking Mansfield Toilet is a simple task that many people will not undertake because the design of the Mansfield flush valve is so different than many other toilets. In reality it is no more difficult than changing a flapper in a conventional toilet.

Most of the Mansfield toilets in service today utilize a unique flush tower design that many people just look at and cannot quite figure out how to work on. There are four basic designs but, all are very similar and just two easily identifiable seals are used on the model 208, 209, 210, and 211 flush valves. The Mansfield flush valves all are secured through the tank with a nut and rubber seal holding it in place. There is a horn shaped tower that has the bell of the horn on top of one of the two seals, the narrow part of the horn goes up above the water line and is held in place by a guide rod with a stop bumper on the top. The tank lever causes the toilet to flush by either going through a loop on the upper end of the horn or, a chain that runs from the bell end of the horn up to the handle. Ether way the tank lever lifts the horn up against the stop bumper, allowing water to flow under the bell end into the toilet bowl, causing the toilet to flush. After flushing, the horn drops back down in place with the bell again sealing against the base of the valve stopping the water flow into the bowl. While the tank is refilling a tube from the fill valve secured into the center of the stop bumper runs water down through the center of the horn into the bowl to refill the bowl to the proper level.

Identifying Which Mansfield Flush Valve Seal To Use

Identifying which seal is use is simple there are only two to pick from.

  • Toilets that have the Mansfield 208 and 209 flush valves use a black rubber seal that secures to the bell und of the horn and the seal raise and lower with the horn when the toilet flushes. Toilets that use the Mansfield 208 and 209 flush valve use the Mansfield # 630-4837 flush valve seal but you may also use a Korky # 426BP flush valve seal. This seal snaps in place over the bell end of the horn similar to putting the lid on a Tupperware container.
  • Toilets that have the Mansfield 210 and 211 flush valves use a rubber seal that is usually but not always red in color and secures in a groove located on the stationary base of the flush valve on the section that doesn’t move up and down with the horn when the toilet flushes. The bell end rises off the seal when the toilet flushes and comes back down on it on the completion of the flush. Toilets that use the Mansfield 210 and 211 flush valves use the Mansfield # 630-0030 flush valve seal but you may also use the Korky # 427BP flush valve seal.

Replacing Mansfield Flush Valve Seal

The replacement of the Mansfield flush valve seal is very similar on all four of the flush valve models. When replacing the black rubber flush valve seal I encourage you to wear latex or, nitrile gloves as the deteriorating black rubber will stain your hands badly and once it is removed I usually hold it in my palm and pull the glove off from the wrist bagging the old seal in the glove. Turn off the water supply to the toilet usually at the stop valve under the left side of the tank. Remove the tank lid and place it on the floor out of the way, placing the lid on the floor is something you should do to prevent the lid from getting broken. (Buying a replacement tank lid can be quite expensive costing up to $150 plus shipping.) Flush the toilet and verify the water is off, then pull the bowl refill tube out of the stop bumper on the on the top of the flush valve. Unscrew the stop bumper of the top of the flush tower and set the stop bumper aside. Raise the horn straight up off the guide rod, turning the loop off the tank lever as you raise it if that is type of valve you have. The chain type just lifts off and the chain does not have to be unfastened. Once the horn is off the procedure varies.

  • If you have the Mansfield 208 or, 209 flush valve with the Mansfield # 630-4837 flush valve seal make sure you use gloves like I stated earlier. Peel the seal off the bottom of the horn and palm it while wrapping it in the glove as you take off the glove to avoid messes. Then take the new Mansfield # 630-4837 or, Korky # 426BP flush valve seal and place the tube in the center of the horn through the hole in the center of the flush valve seal while snapping the outside of it over the bell. Make sure that the seal is flat and not rippled anywhere or, cocked on the center hole. You are now ready for reassembly.
  • If you have the Mansfield 210 or, 211 flush valve with the Mansfield # 630-0030 flush valve seal set the horn aside. The seal fits into a groove on the flush valve, simply grab the seal and pull it outwards stretching the seal out of the groove somewhat like undoing a button and remove the old seal. Take the new Mansfield # 630-0030 or, Korky # 427BP flush valve seal and place it in the thin upper groove on the flush valve working around the entire valve then stretch it getting it into the groove on the last section. Inspect it making sure it is in the upper thin groove all the way around. The seal is thin and probably rippled from not seating correctly. Take the seal and rotate it around in the seal and back and forth. The seal will seat properly and rest flat. You are now ready for reassembly.

Reassembly of the Mansfield Flush Valve

Place the horn bell end down over the guide rod sliding it down into the position rotating the tank lever into the loop as you guide it down if that is the type you have. Lower the horn to the closed position, then screw the stop bumper back on. Place the bowl refill tube all the way back into the center of the stop bumper. You are now ready to turn the water supply back on and test the operation of the toilet. Your Mansfield toilet should flush properly and not leak water from the tank into the bowl. Replace to tank lid and cleanup you have replaced the flush valve seal.

Posted in How To Plumbing Tips, Toilet Repairs, Water Conservation Tagged with: , , , , , , , , , , , , , , , , ,
120 comments on “How To Repair A Leaking Mansfield Toilet
  1. Sandi says:

    Ahoy, I have 2, yes 2 Mansfield toilets that have all of the above problems. Yes I have tried all and I do mean all of the above solutions to my “hard to flush” “leaks into bowl” “bad gaskets” etc. etc. To all that attempt to repair a “Mansfield” toilet, my prayers go out to you. Be smarter than me and just take a large sludge hammer, or any large object and start swinging at your toilet. It will cost you more in gas, and all those little parts. universal or otherwise. The stress alone might just cost you thousands in therapy!! Mansfield toilets should be outlawed, banned, or just maybe blown-up. This has to be the worst of the worst ever invented. I am now plowing the small strip of land next to my house so I can construct a small building with a small half-moon on the door. Yes I will gladly use an OUT-HOUSE before plopping my fanny on a Mansfield.

    • Redwood says:

      Hi Sandi,

      You’ve summed up the frustrations of those who haven’t mastered the Fine Art of Mansfield Toilet Repair pretty well, they aren’t an easy one to repair. Thanks for today’s belly laugh. What brand are you going to try next?


  2. Gabriel says:

    I have also had issues with the leaking gaskets, hard to flush, etc. after going over several times, I realize that I was simply pushing the gasket down too far. It is only supposed to go in the first groove. Shouldn’t require any pressure. It takes less than 30 seconds to fix.

    Now my issue ist that it is leaking around the ball cock design which attaches to the water supply. I’m about to toss mine out as well if I can’t fix this. Just too much time invested. But at least I have a better understanding. :-)

  3. Gwen says:

    This is great. You couldn’t have explained the procedure better. I have also been reading the comments which have helped a lot. I have a Mansfield 208/209 model toilet. It “trickles” and sounds like a babbling brook. I replaced the flush valve seal and it still trickled. I took it apart and realized I didn’t seat it properly on the center hole and thought that would surely fix it. It still trickles. Do I need to replace the flush valve? If so, do they still make them because I can only find the 210 flush valve. Thank you for the help.

    • Redwood says:

      Hi Gwen,
      The 210 Flush Valve is the current replacement. Did you use a Mansfield OEM Replacement Part? I had tried some off brand parts in the past from a big blue store that I had a lot of problems with getting them to seal. I suspect the rubber was harder and causing the problem.

      Another thing to look at is the bowl refill tube coming from the fill valve over to the flush valve. If the fill valve has been replaced some fill valves have a thinner tube and it may be possible to insert this tube too far into the flush valve. If the refill tube goes below the water level in the tank it can siphon water from the tank into the bowl bypassing the flush valve seal.

      Hope this helps,

  4. Gwen says:

    Thank you Redwood. I did use a Fluidmaster part from HD. The fill valve has not been replaced recently (and possibly never). I did locate the Mansfield website for parts because I don’t believe I will find the part locally. Thank you. I will let you know how it turns out.

  5. Cathy says:

    I am trying to replace a seal on a Marshfield 210 toilet. You say to “simply grab the old seal and pull it out.” Seems easier said than done. It is tight to the bottom of the tank and I can’t get a grip on it as only a little bit sticks out from the flush valve. Do I need to remove the tank from the bowl? I’m frustrated to the point that I’m debating whether I should give in and call a plumber or just replace the whole toilet…

    Am I missing something?

    • Redwood says:

      Hi Cathy,
      What color is the seal you are trying to remove? If it is black, you are trying to remove the flush valve gasket, which is the wrong one! Look at the picture of the Mansfield Toilet Tank Parts on the above left side of the page, in particular the bottom 2 pictures in that picture, the part you need to be removing is shown in red. This seal may be red, white, or, a light blue/grey and it should be something you can grab. It may also have broken and come off or loosened and come off. If it is still in place you might try using a pair of needle-nose pliers to grasp it.

      If the seal has come off look down inside the hole the water goes into when the toilet is flushed and see if the old seal is in there. Remove it if at all possible. The old seal if lodged in the internal water passages of the toilet may block the water flow and cause a weak flush or, it may have no effect at all. If it is still in the tank somewhere remove it.

      Hope this helps,

  6. Miss Lopez says:

    I have a 210 flush valve and the blue plastic stopper at the top is broken so now every time I flush it hits the refill hose and knocks it out. Is there anyway I can buy just that piece or do I have to buy a whole new flush valve?

    • Redwood says:

      Hi Miss Lopez,
      The part you are looking for is sold separately and can probably easily be found On-Line. I’d suggest searching for a “Mansfield #225-5907” and the stop cap should come up in your search. The color may vary but all of the caps are the same.

      Hope this takes care of your problem,

  7. Bob says:

    thank you google! this is great info on this old toilet part. What about 208 209 does it use the same stop cap, my broke too. it’s not like everyone carry this little stopcap.

  8. Steve says:

    My two Mansfields would always trickle after changing the gasket. I found if you use two of the red gaskets it works. One in the upper groove and one in the groove below. No where is this instructed in anything I have seen but it works. If I use one it doesn’t..

  9. Tom says:

    I have a Mansfield 160 that continues to run after flushing. The only thing that makes it stop is to pull up on the float ball lever and that cuts the water off. What is the best way to fix this problem?

  10. Esten Jefferson says:

    Hello. I have 3 Mansfield 160 toilets. All of the red seals were bad. I looked at this site before and you said to use the 210/211 seal. I have replaced them all. Two of them work perfectly now, thanks to you.
    Now, though, one of them continues to leak, although at a miniscule level. What seems to be the problem?

    Help is greatly appreciated!

    • Redwood says:

      Hi Esten,
      The first thing I’d try is making sure that the red seal is sealed properly and is in the correct groove. Try rotating it as I have described numerous times on this page and in the comments. Next I’d make sure that the bowl refill tube isn’t inserted too far into the flush valve so that it extends below the water level in the tank, this can cause siphoning of the water into the bowl. I’d also check the bottom of the flush valve horn and make sure that there are no rough areas that will prevent a proper seal.
      Hope this helps,

  11. WinniNH says:

    When changing the flush valve seal on a Mansfield Watersaver 208, is it necessary to change the spud gasket, part # 447-0200?

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