Kohler Part 85406 2" Toilet Flush Valve Kit, Colors may vary

This is the exact part I needed to replace the tank seals on my Kohler toilet. After reading the various reviews, I was concerned that the round sealing washer would not be in my kit although it does show in the diagram photo of parts included in the kit. However, when the kit arrived, it included everything I needed: fill valve with seal, the triangular seal, all bolts, washers, and fasteners, as well as the round large washer and the screw on attached ring. Perfect. The hardest part of the job was unscrewing the old attachment ring as the original plumber installing this toilet had tightened it very firmly. I wound up pulling the old triangular ring off (somewhat in pieces) with the attachment ring still on. Then I was able to more easily access the attachment ring and unscrew it (it came off without too much effort...actually without a tool just by hand.... once the black rubber triangular seal was gone). I was able to install the new black triangular seal, the large washer and then the new locking ring without any problems. I was also able to get the new locking ring snug without too much tightening using a large pair of channel locks. I made sure it was tight, not leaking, but did not make it so tight that it would be impossible to remove if I needed to (aka the previous one). It's been 5 days now and absolutely no leaks, working perfectly. So, this kit does indeed come with everything showing in the diagram photo...everything you need to change out the filler and tank seals.

My toilet was previously repaired using a generic flush valve designed for use in most toilets. It worked fine for years but eventually failed. I struggled with spending money for an OEM replacement at first and then I researched, back to the last time I repaired a toilet using the higher priced OEM parts and, it was a long time ago. In fact, so long ago that, even with the price difference, the OEM part worked out to be the cheaper choice. This part is no exception. It was a straight forward installation with no need to adjust or modify anything as it's exactly what the manufacturer designed for my toilet. Because of that, the replacement was straight forward, quick and, after completion, a quick leak check was all that was required. No time spent or water wasted adjusting things.

This product was the perfect fit and replacement of the flush valve on my Kohler Wellworth 4620 toilet (circa 2000) which had a ghost leak causing the fill valve to periodically cycle. Multiple flapper replacements did not solve the problem, which I now suspect was related to water from the tank bypassing a worn gasket on the flush valve and entering the bowl. Installation involves disassembling the tank from the bowl by removing the three (3) brass bolts (set aside for re-installation). Note the orientation of the flush valve to the tank rear bolt hole before removing, so that the bolt hole is not covered by the new flush valve when installed. A large set of lock-jaw pliers (i.e., Channel Lock) may be needed to remove the large nylon nut securing the old flush valve to the tank. Install the new triangular tank gasket and flush valve to the tank, orienting the flush valve as previously noted (to not cover rear bolt hole) before tightening the large nylon nut. Reattach the tank to the bowl, carefully following instructions to alternate tightening the three (3) bolts a small amount at a time. If the tank gasket leaks at bowl attachment point after installation, remove tank, re-seat and tighten bolts as described above. Other reviewers suggested purchasing replacement bolts, but the flush valve kit that I received included bolt, washer and nut hardware for installation. I decided to use my original brass hardware (old school) which were in good condition, instead of the hardware provided with the kit which included zinc bolts with plastic coated heads. I noted that the replacement flush valve is a lighter gauge plastic than the original part, but that should not affect its operation. It's possibe that I could have just replaced the flush valve rubber washer (Part 53154, replaced by 1145626) and bowl gasket (51487, replaced by GP51487) assuming that the flush valve plastic did not have a crack, but it's probably safer to just buy the entire 85406 assembly which also includes a new Kohler flapper. See Kohler 4620 toilet Parts Diagram on Kohler web site. Also check out videos on the Kohler web site and Youtube for more instructions.

Product works fine once installed correctly, but the instructions are misleading. They say to tighten the flush-valve tank nut “¼ turn past hand-tight,” which wasn’t enough. My tank kept slowly refilling every 20 minutes — classic “flapper leak” symptoms — even after replacing all parts. After considerable frustration, I found a comment on another brand’s product noting the same issue. The fix was simple: tighten the flush-valve tank nut another half-turn with a wrench until firm resistance. Leak stopped instantly. So: solid kit, but the printed guidance should warn that an under-tightened flush valve nut will mimic a leaking flapper. Once fully torqued, everything works perfectly.

Had water leaking into the bowl. Generally, a replacement or thorough cleaning of the flapper will improve this. In my instance, I turned off the water source, flushed the toilet to drain the tank down to the top of the flush assembly. The flush ball was removed to ensure the water was below the top of the flush ball assembly. I then left for a few hours and on my return the tank was totally empty. This pointed to the need to replace the entire flush ball assembly (or maybe just tighten the three tank bolts). The new kit, GP85406, comes with everything you need to ensure the repair is complete. The redesigned rubber gasket is the biggest improvement. The rubber piece no longer interferes with tightening the large retaining nut and you are able to attain a proper seal (Hand tighten until tight and then turn another quarter turn with proper wrench). I reassembled the tank onto the base, and tightened the three new bolts. The new bolts are superior to the old brass screws that required a large flathead screwdriver to hold the bolts in place while tightening the three nuts. The new bolts have caps that allow you to hold them while torquing the nuts on the underside. Like installing a wheel on a car, slightly tighten each bolt and then move across to the next nut and continue slightly tightening each bolt until the tank is secured. Don't fully tighten down one bolt and move to another as this may lead to a cracked tank or bowl. I use a level to ensure the tank remains level as each bolt is slightly tightened. Reattach the water source and fill the tank. I then turn the water source off and monitor the water level to see if it is holding at the fill level. Keeping an eye on the bowl to see if water is trickling in is also advised. However, water will often continue to seep into the bowl for a short while after the tank is filled. Give it time and then check the bowl for water flowing down the interior of the bowl. If the water level in the tank is decreasing, either the flapper is leaking or the tank is not properly seated on the bowl. This is a simple project and the skill level to complete the project is a one or two. Just take your time tightening the three tank bolts and do not rush this part of the project.

This was a genuine Kohler OEM Flush Valve Kit, part 85406. I also purchased the Kohler Genuine Part Gp1138930 Silent Fill Toilet Fill Valve Kit. I figured let me replace all the working parts since I couldn’t figure out where the problem was coming from. If you only have to replace the fill valve, then you’re in luck because the fill valve is pretty easy to install. But replacing the flush valve is a whole other story and that’s because you have to get to the gasket and that requires you to remove the toilet’s tank. So although the working parts are both quite easy to install, removing the tank makes this diy project, a bit more labor intensive. Luckily, I have a lot of room on both sides of my toilet because I can’t imagine having to do this in a tight space bathroom! Considering you have access to parts of the toilet that you don’t normally get to, I took the opportunity to clean everything up with a vinegar and baking soda solution which was supposed to lighten up the water stain in the tank. I think it did lighten up a bit but it certainly did not remove it completely. Also make sure you have the right tool to remove and install the type of screw bolts used to attach the gasket to the toilet tank because these bolts can easily be stripped and you don’t want to have to do this again nor do I believe that Kohler sells the screw bolts separately, at least not OEM. Also, you may not be able to get the screw bolts off the tank if they become stripped. I think removing and installing the gasket and screw bolts was probably the worst part of this diy project. And be careful not to tighten the screw bolts too tightly because you can easily crack the surrounding ceramic opening on the tank! Seriously, be careful with this part of the job, you don’t want to compromise the integrity of the toilet tank.

Worked great. Turned out I replaced the part unnecessarily. I had a mysterious leak that I thought was caused by a faulty fill valve. Problem was not fixed. Then I replace the flush valve system (which I am reviewing here). Still had a minor seep from the tank into the bowl which caused the bowl and tank to sweat more than normal. Finally, I figured out the fill valve post was adjusted too high and the shut off valve was hitting the tank top causing the valve to leak incessantly. Problem solved when I lowered the post. Duh. Parts should have been replaced anyway due to heavy scale build up from my unsoftened hard water. Lesson here: Make sure the fill valve post is adjusted low enough after replacing it.

Who knew it only took $20 and a bit of effort to restore a toilet to like-new condition! This kit was almost exactly what was needed to stop an extremely slow leak into the bowl that caused the tank to re-fill randomly whenever the water level would eventually get low enough. You can easily tell just by looking at the inside of the tank to see how worn out the gasket is (if you can see it worn out, you probably need to replace it). I used this entire kit as-is so all parts would be new. Even the water line isn’t a sticker anymore that eventually just peels off, so that’s great too! I replaced two identical assemblies for each of the tanks and both are working perfectly now! It’s a challenge to remove the old worn parts because you have to drain and remove the water tank too, but the effort was totally worth it, the existing parts were very old and were definitely causing the problem. You won’t have any trouble if your tank is meant for this kit, it will work perfectly, absolutely no leaks now! But the flush valve that comes with this kit was terrible because it didn’t include a tiny pin hole to allow it to fall back down and cover the opening. I had to buy two new flush valves and then return the defective ones. I hope that was just a one off with these kits, because if not, it will be obvious when your toilet double flushes every time. Make sure your flush valve has a small hole in it or it’s definitely not going to work because it will just stay up all the time, no matter how high you adjust the float. It’s a small detail I never even noticed until I bought two new flush valves and could compare the difference side-by-side. With the right flush valve with the hole in it to allow water and air to escape, the float will actually work, I brought the float down closer to the valve because I wanted a stronger flush and no clogs. Hope this helps.