If you’re like me, you don’t even know what the parts inside a toilet are called. All you know is that it is taking all your strength to push that little handle that flushes the toilet. What’s up with that?
If your toilet has suddenly become really hard to flush and it feels like the plunger is “sticking” at the bottom, then chances are the flush valve seal needs to be replaced.
What Is the Flush Valve Seal?
The flush valve is the contraption that controls how much water flows from the tank into the toilet bowl. Sometimes it looks like a flapper with a chain coming out of the top. Sometimes (as in Mansfield toilets) the flush valve looks like a tower that lifts up to let the water flow or settles down to stop it. The seal on the flush valve is a rubber ring, and over time it can deteriorate. When it does, it gets harder to break the suction and let the water flow through the valve.
Flush valve seals are usually available at hardware or home improvement stores. Make sure you know who manufactured your toilet before heading out to the store to buy a new one.
Note: If you’re picky about the way your hands look, make sure to put on a pair of latex or close-fitting rubber gloves before starting your toilet repair. The water in the tank is clean, so there’s really nothing nasty about this repair. But if the deteriorated seal was black, sometimes your fingers can get smudged with an inky residue.
How to Replace a Flush Valve Seal
In order to replace the flush valve seal on a Mansfield toilet, all you need to do is follow these simple directions.
Step #1: Turn Off the Water
Turn off the toilet water supply behind the toilet where the pipes run into the wall. Flush the toilet so the water empties out.
Step #2: Disconnect the Water Refill Tube
Disconnect the water refill tube. This is a little bendy tube that goes into the top of the whole tower assembly. Just pull it out gently.
Step #3: Unscrew the Cap
Unscrew the cap that the refill tube goes into. It looks like a little flat donut, and it’s wider than the flush valve tower.
Step #4: Lift the Flush Valve Tower
Simply lift off the flush valve tower as shown in the picture above.
Step #5: Remove the Old Seal
Take off the old seal. It’s rubber, so you can pinch it and pull it out like a rubber band. (This is where you might get that inky black stuff on your hands.)
Step #6: Put on the New Seal
Put new seal into space between top two grooves. When it’s fitted in properly, you can gently turn it.
Step #7: Put Everything Back Together
Now that you have the new seal on, all you have to do is put everything back together. Slide the tower back on, screw on the cap, slide the refill tube back in place, and turn on the water again. You're done!
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Question: The flapper in a toilet I took a look at seals too well. It makes pushing the lever down extremely difficult. How do I get it to loosen up a bit? There is no chain to shorten.
Answer: That's exactly what my article is about -- that problem of "sealing too well." The solution is to replace the flapper, or whatever seal connects the two parts, because the rubber seal has deteriorated.
In a Mansfield toilet, there's a rubber ring between the two plastic parts of the tower assembly. That's the part that can be replaced. I don't know what kind of toilet you're referring to, so you'll have to look closely and see if there's some piece with a rubber part that is causing the problem.
Question: I have done this repair several times over the years but this time after replacing the seal with a new one it is still EXTREMELY hard to raise the flush tower with the handle. Also the tower sometimes stays up after emptying the tank. Any ideas?
Answer: Hmm. That's a puzzler! I'm not a plumber, just a DIY person, so my advice is: 1) Check to see if anything's rusted or broken around the handle or the connection with the flush tower, and if you don't see any easily fixable problems in those areas, then 2) call a licensed plumber. We should all be capable of fixing simple repairs, but when the problem isn't simple, it's time to call in the experts!
Question: What size ring do I purchase for my Mansfield toilet?
Answer: It depends on the model of the toilet's flushing assembly. I only found one size rubber replacement ring that was designed for a Mansfield toilet. I believe it's called a Mansfield Flush Valve Seal.
If you're finding more than one option, the easiest way to be sure that you have the right one is to remove the old one and take it with you to the store.
Question: What do you do if the tower doesn't seal on a new seal washer?
Answer: I haven't had that happen to me -- in that case, I'd suggest trying the following:
1. Take the flush valve seal off and then re-install it to make sure it's properly placed, or
2. Inspect the tower assembly to make sure it's not broken or otherwise damaged so it won't seal to the new flush valve seal. Replace that if necessary.
If neither of those procedures work, then it's probably time to call in a professional, because the problem may not be a simple matter of replacing the rubber flush valve seal.
Question: Does the handle lever go thru the loop on the side flush valve tower before you connect the small chain?
Answer: The lever does go through the loop on the side of the tower, but our Mansfield toilets don’t have a small chain. Still, you do need to make sure the lever goes through that loop, or it won’t lift the tower.
Question: The tower part keeps sticking to the gasket, why?
Answer: The gasket, or rubber ring, has deteriorated and needs to be replaced. If you’re asking why that happens, maybe you need to ask someone more knowledgeable about science than I am.
Question: I changed the seal and now there are air bubbles coming in at the bottom. The tank doesn’t fill up. What should I try next?
Answer: Although I'm not a plumber, just a DIY person, it sounds like the seal isn't in the right place. Take out the rubber ring (the seal) and feel along the edge of the tower to find the ridges within which the seal is meant to be fitted. Then try re-inserting the rubber seal so that there's one set of ridges on either side of the seal.
If that's not the solution, then it's time to call in a professional.
© 2011 SaraleeEtter
Kylie on August 24, 2020:
Worked like a charm! Thanks so much for sharing these simple directions!
Barbara Z on November 03, 2019:
The step by step instructions are like text-book for elementary kids, i followed it words by words, it worked like a charm that ended my month long struggle, thank you so much Sara for sharing this wonderful article with us!
Barb on July 04, 2019:
Thanks so much for these clear instructions! I was able to do this repair myself rather than waiting for my handy brother-in-law or spending money on a repairman.
mdd on June 25, 2019:
Very easy & cheap fix. Thanks!
Tommy on March 29, 2019:
I did that. Still hard to flush.
Kelli on October 21, 2018:
Thank you! Just the info I was looking for.
mmgm on September 30, 2018:
Perfect! These instructions are exactly what I needed! I suffered forever with the hard to flush handle and literally it took 4 minutes to replace and couldn't have been easier. At the hardware/plumbing store (I found the part at Lowe's), the Flush Valve Seal package will be light blue and the seal is red; the package will say 2" For Mansfield #210. ITEM #247876. UPC is 4622404895. It only cost $2. Made by the Keeney Manufacturing Co. One tip: The bottom of the tower may have some rubber gunk on it which transferred from the deteriorating seal, so take some toilet paper and clean off the gunk to ensure you get a nice tight seal. Oh, and if you have more than one Mansfield toilet, you might as well replace all of the seals at the same time while the process is fresh in your mind. All 3 of my toilets' seals were starting to go bad and make the toilet hard to flush.
Paul on July 31, 2018:
Just tried this yesterday and I worked perfect, thank you for the clear instructions with pictures!
hal on July 17, 2018:
short fix: Remove the "tower", coat seal with axle grease, replace tower, Good until you can get to a new seal.Side bar: these are the bottom to the line in water closets. Convoluted discharge path & small diameter discharge. I would suggest owners of these water closets have stoppage issues also. If you choose to replace, use an American Standard or Kohler elongated toilet. You will not be sorry.
Kathleen May on March 17, 2018:
I don't believe it, it's fixed in minutes with a $2.99 washer. I've been lifting the lid for months to flush in fear of breaking the handle. Thanks
Sue on December 20, 2017:
Bless you! I am a woman who now feels grrrreat!
David on November 12, 2017:
Thank you so much. I know it had to be something simple but just wasn't sure. You and your pictures made it as easy as 1,2,3. Thanks again
Sundaram on October 30, 2017:
i am out of words to thank you!
The steps are so simple. You saved me a lot of time and money. Thanks again for your big heartedness!
Rob van horn on September 30, 2017:
THANKS, EXACT PROBLEM I'M HAVING
Matt on September 23, 2017:
Larry on September 11, 2017:
I can not believe I have put up with this problem for years.
Excellent write up and pics. Thanks
Fred on August 22, 2017:
Turned out to be an easy fix, thanks for the great pics
tjwilliamsphotography.org on May 04, 2017:
Thank you so much, SaraLeeEtter!! My flapper is easy to unseal, again;)))
chabias on March 16, 2016:
Nice, clear instructions. Thanks!
hoodman on July 19, 2014:
awesome article.... solved my problem.!!!
Rob on May 28, 2014:
Here's a tip to save some cash and/or a trip to the Home Depot. Take out the tower as described. Rather than removing the seal, just use ~120 grit sand paper to lightly sand the bottom of the tower, along the edge where it connects to the seal. Not sure how long this lasts, but it fixed mine just now. If the seal is too tight, making the plastic slightly skinnier seems like an easier fix than a replacement.
Nita8 on May 27, 2014:
I used the red ones on two toilets, and it's been almost two years ago, and they're still working fine for me. One of them is for a guest bedroom bath, so that wouldn't make a good example since it's not used that much. But the other is in the main bath and is used daily, and it's good, too. Anyway, that's been my experience, but the off brands may have more than one manufacturer. Maybe I just got a good one!
You can see my prior comment under Nita8 above.
Miss Nancy on May 26, 2014:
Use only original Mansfield black seal. If you use an off brand or the red ones, it will leak again in 3 months. I go to Ace Hardware and get the factory correct seals.
jen on May 03, 2014:
Just did this with your step by step instructions at my side --thanks sooooo much!!!
Jill on April 29, 2014:
Thank you so much for this! After breaking two flush levers from a very hard to flush toilet this seems to have fixed the problem. The pictures were a great help too!
Kenya on April 12, 2014:
It was so easy and fast.
the irony on November 24, 2013:
From one PR gal in Central Ohio to another, this solution worked perfectly. -- M Vroom
wc on November 10, 2013:
thanks a lot for your detailed instructions! step #6 regarding how it should be fitted is the key. i appreciate your help very much!
Jeff on April 16, 2013:
I had a similar problem and was pulling my hair out as I couldn't fix it. I then found this (http://www.toiletrepair.ca) which pointed me towards the float valve. Mine was damaged in the same fashion as what that site depicted. I followed the directions and bam - my toilet was repaired.
liamm1320 on January 03, 2013:
It's always a bummer when you can't figure out why your toilet isn't flushing. We've been having that problem for a while now. Do you have any suggestions? My friend said to go here: http://www.aalertdrain.ca/en/, what do you think?
Golobulus on January 03, 2013:
This worked! Just replaced these on all of our Mansfield toilets and they are easy to flush again. Thanks for the article!
CC on November 24, 2012:
Thanks for making a detailed yet simple guide to follow for the repair. Thank
Josh on October 17, 2012:
The worst toilet money can buy.
Even after changing the guts they don't flush great. They have a flat spot after the trap. Replace the toilet!
Saleem Wani on September 24, 2012:
Thank you for great Instructions. I followed your instructions and my Toilet is working like charm again.. Thanks again....
fixitsister on September 14, 2012:
My husband was zip-tying the handle to the tower as the suction was so intense it broke the original. Thanks for walking me through this! We have company coming and I didn't want a toilet that was difficult to flush. You have a gift for true step by step directions. Thank you, Saralee!
phumla on August 06, 2012:
thank you thank you thank you so much!!!!!!!!!
Nita8 on July 27, 2012:
Thanks! You just fixed my two Mansfield toilets! We've almost broken the handles on both of them trying to flush. Now, we can use one finger. Thank goodness for people like you who are willing to take the time to write these articles. Photos were very helpful.
H on July 10, 2012:
Thanks for the DIY page. Pictures and instruction were great. Two problems I ran into:
1. There are two types of Mansfield valve seals, the tower one here which is a red circle and a second one that is black and looks totally different. Didn't look at the picture closely and bought the wrong one assuming there was only one Mansfield seal.
2. A lot of black gunk filled the toilet reservoir while trying to get the old seal off. It's helpful to turn the water back on to clear it out as it totally obscured the bottom of the tank. Just make sure the refill tube is pointed in the tank.
Carol on May 22, 2012:
I did it!!! Thank you SO MUCH for this helpful article. Our toilet has had this problem for the last few years and I was ready to call in a plumber. This was such a simple fix even I could do it! I especially appreciate the heads us on the black stuff. Would have been real unhappy to get that all over my manicure. :)
Mike on May 03, 2012:
Thanks for the info Saralee. Had the same problem. Thanks also Sanjay for your comments.
Alla on April 17, 2012:
Thank you so much for this tutorial! I have been looking for a solution for our hard to flush Mansfield toilet. Now I can finally fix it!
Strong on February 28, 2012:
Thank you so much for this information:)
sanjay on February 25, 2012:
I had same issue which was fixed after following your instructions,however there were some issues like water leaking in the bowl (inside) so tank keeps filling up sound keeps coming up.
Issue was fixed with seal put in top groove and rotate to see it is moving. There was a black ring from where the color was coming,that should not be removed, only red color seal which sits on top of black seal.
Here is another video which was very helpful.
Thanks a lot.
Dave on February 23, 2012:
Thanks. Great instructions!
Cindy on October 31, 2011:
Wow! Thank you so much for the info.& step by step instructions (& pics)! That is my exact toilet and until now have had a hard time finding the answer to that pesky flushing question in my head! My lever broke and after relpacing is still hard to flush and now I know why and how to fix it! Mucho thanks!
Jodelle Brohard on August 26, 2011:
Great article! I know a lot more about the inside of my toilet tank now than I did before.
SaraleeEtter (author) from Ohio on August 26, 2011:
Thanks so much, Robin!
Robin Edmondson from San Francisco on August 25, 2011:
Thanks for this excellent guide. I loved all of your original photos and the topic is great for those that have that type of toilet! Welcome to HubPages. You are off to a fantastic start with only 2 Hubs. Wow!