Finally! The differences between the 528 and the 528T !

Discussion in 'Toilet Forum discussions' started by lee_leses, Jan 6, 2009.

  1. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Replace the "cap" part of the fill valve.

    I had a detailed talk with technical support at Lavelle / Korky today because i'm still having trouble with the 528T fill valve in this Ultramax. Although it is barely audible, the valve seems to shut off 1/2" below the overflow tube, but then over about 20 minutes the water level climbs the 1/2" to the top of the overflow. You can see in the tank the water line has been rising up to the top of the overflow for a while.

    I replaced the cap with a new one, but the slow leak continues. So I called Korky for a question and answer session. I found out a lot and wanted to share it.

    The standard "quiet fill" 528 available at Lowes is NOT the proper fill valve for the Toto toilet! If you use it, the fill ratio between the tank and the bowl is not correct, and will result in low bowl fill levels.

    The part of the valve that is different in the 528T, if I understand, is something in the main black body that screws to the bottom of the tank. The special part is NOT any of the parts that the red part of the valve seats to or the black filter stack that has the filter in it that pulls out. The cap is the same for both the 528 and the 528T, as stated on the package the cap comes in.

    I then asked why the 528T is so much more expensive than the standard 528. I was told it's because the modifications to the 528T are done by HAND at the factory resulting in much greater labor costs. Per the rep, the part that is modified is called a "flow restricter."

    I asked if Korky / Lavelle valves are used in brand new Toto toilets, and I was told yes, that Korky makes some, but not all of the fill valves that Toto either did use, or does use. I'm not sure if Toto is still using Korky parts or not, but they were. I asked if Korky plans to continue to make the 528T and the rep said as far as she knows, yes.

    Lastly, the rep told me that there is a black rubber part in the float assembly that I should try to pry out and turn over to use the other side of it. If that doesn't stop the slow leak then I am to try replacing the entire assembly or at least the float part from a new valve. She said the float part is the same and I could use a float from a standard 528 from Lowes which is what I will try next.

    It's SO much easier having this information available 24/7 rather than having to catch the company during the day when they're open. I hope this helps someone!

    Lastly, the cheapest price by far that I found online for the 528T was at Ace Hardware Outlet for $16.09 + shipping.

    http://www.acehardwareoutlet.com/(4yitedfdtsv405ixpg1b53mo)/ProductDetails.aspx?SKU=4284162&
    Last edited by a moderator: Jan 9, 2009
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    This is interesting. I wonder if the problem is that the "regular" 528 is for non-1.6 toilets? It seems like if the toilet flushes 1.6 gallons, then it needs to refill 1.6 gallons, no matter what brand. Possibly the Toto toilet bowls hold more water ( bigger spot) and hence take longer to refill. Makes me wonder if they are really using MORE than 1.6 gallons per flush!
  3. CarlH

    CarlH New Member

    Messages:
    175
    Location:
    Northern VA
    I doubt that they use more than 1.6GPF. I think I did see in some testing that they indicated how much the various toilets actually used per flush. It may have been the MaP testing. They probably make up for the difference by dropping less from the tank when flushed. If I rember correctly, the pressure assist toilets may have used slightly more at 1.7GPF. I don't remember if they indicated what the water pressure was.

    As for the Korky fill valves, I think that this higher manufacturing cost may be the reason why Toto went with the WDI fill valves. I looked at the WDI web site and some of the fill valves have different flow restrictors available to adjust the amount of water for the bowl fill.
  4. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Carl, thats interesting.

    Is WDI the "Vortech" fill valve Toto is using now, the one that supposedly had all the full shut off problems? I found WDI's website and I see what you mean about adjustable refill rates. There's also an optional flow restrictor of some kind, is that to compensate for high water pressures? Wow this is complicated! LOL Which of WDI's fill valves is Toto using, or do they use several different ones?

    As for the 528 valves, I'm trying to figure out too why the "universal" valve works in most toilets except the Toto. I'm wondering if it has something to do with the way the Toto 3" flush valve empties the tank so much quicker that the refill tube runs for a shorter time (because it takes less time for the tank to empty and fill again maybe?) to fill the bowl and therefore has to run faster to fill the bowl before it shuts off. Also, I think the "spot" might be bigger than many toilets, I think I heard that about Toto and you can see it too maybe?
    Last edited: Jan 7, 2009
  5. Probedude

    Probedude New Member

    Messages:
    137
    Location:
    CA
    To me it seems that my EcoDrake just empties more completely, so there's more water to replace vs the old toilet where the water would backwash into the bowl once the siphon is broken.

    Regarding " hand modified" to make a 528 into a 528t, I'm guessing it's just reaming out an orifice bigger or replacing a pressure compensating rubber restrictor with a different sized one.

    Lee, the center tube sliding mechanism of your Korky could be leaking too. The stem telescopes up and down in something and that seal there could have a pinhole or tear in it.

    Lastly, have you checked your water pressure?
  6. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Thank you very much Probed for your thoughts!

    Since at this point I MUST know, I ordered both a 528 and a 528T to take apart and inspect. LOL

    Since I didn't touch the fill valve for 6-7 years, I am wondering if when I touched it to work on it I made a small crack in the tube body or disturbed a now brittle seal. That is on my list to check but i'm going to try the less invasive things first before I try replacing the entire valve.

    Lastly, forgive my ignorance, but are you thinking pressure that is too high as opposed to too low? I assume only too high could be a problem? How do you check that anyway?

    Also, I figured out that ever since new my Toto only flushes right if you hold the flush lever down until the tank empties completely. How do adjustable flappers work? Would an adjustable flapper of some kind keep the flapper open until the tank drained completely, or is there some kind of adjustment for the "stock" flapper that I don't know about?

    Replace the "cap" part of the fill valve.
    Last edited by a moderator: Jan 9, 2009
  7. CarlH

    CarlH New Member

    Messages:
    175
    Location:
    Northern VA
    I did not see a fill valve on the WDI web site that was an exact match to the one used by Toto. The B3800 looks close except for the cap and the shape of the float. The B3900 looks close too but the position of the adjusting screw is different and there looks like there is an additional lever or linkage involved with the float.
  8. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Hmmmm.

    I was also wondering why they need so many different fill valves to get the job done!

    Lee
  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,059
    Location:
    New England
    Before water conservation was mandated, it didn't matter much...most filled the bowl maybe twice before the tank was full and it shut off - the valve is in the tank, not the bowl. Now, with varying designs, some have a big water spot and require more water for the bowl verses the tank, and vice-versa. To get both the tank and bowl to fill at the same time would vary by the specific implementation. THus, the valves must be tailored to the application or you will end up using more water than you should or the bowl won't be refilled by the time the tank is and performance would suffer.
  10. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Thank you. That makes a lot of sense.

    I must say, I wish I was in New England right now, maybe on one of the islands there. Certainly not in PA like I am... LOL
  11. Redwood

    Redwood Master Plumber

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  12. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Finally!

    The valve stem on the left is the universal 528.

    The valve stem on the right is the 528T. As you can see there is a blue flow restricter. As far as I figure, it either slows the water flow into the tank, or forces more water into the refill tubing, i'm unsure which. But there's the main difference. There's also some minor differences in the part that contains the float. The holes that allow water in and out of the float chamber are a little different.

    In the other pic, it shows the parts that bring the water up from the supply line to the valve. There is an "O" ring and the smaller tube in the picture slides into the larger tube. The white piece, the strainer, slides into the smaller tube.

    If the valve still leaks after I replace the float, then I think the "O" ring is worn and has a slow leak. Then the whole valve will have to be R & R'ed.

    That's assuming the "O" ring is there to provide a water tight seal and not just to make the two tubes glide over each other smoothly, i'm still not sure about that if the "O" ring has to be right to keep the valve from having a slow leak into the tank - or not.

    http://home.earthlink.net/~lee_leses/528
    Last edited: Jan 10, 2009
  13. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
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    Location:
    Cave Creek, Arizona
    flow

    Kohler has been using a "flow restrictor" in their Fluidmaster 400A fill valves for years, and the Fluidmaster "Pro" series also has it. The restrictor is also the reason Kohler toilets eventually take forever to refill until a rod is pushed down the fill valve to remove it. And it would take all of 5 seconds to place it in the fill valve's inlet and shove it up into place. Sort of like a hemorhoid treatment.
  14. Probedude

    Probedude New Member

    Messages:
    137
    Location:
    CA
    The o-ring is to make a water tight seal since the water supply is fed through this tube.
  15. Terry

    Terry Administrator Staff Member

    Messages:
    15,053
    Location:
    Bothell, Washington
    Jamie can talk a housewife through the replacement of the cap over the phone in about a minute.

    We don't recommend replacing the fill valve, only the quick and easy cap replacement.

    www.terrylove.com/korky
  16. providence

    providence New Member

    Messages:
    9
    Location:
    Ohio
    Can you tell me why you don't recommend replacing the fill valve? I was planning on doing that today.
  17. Probedude

    Probedude New Member

    Messages:
    137
    Location:
    CA
    but the original guy already said

  18. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Terry and others:

    This may be premature, because I'm just going up now (10:30pm) to try messing with the "pilot" seal in the float and the top of what I'll call the fill tube, the top tube in the "O" ring assembly. But I wanted to ask for tips and tricks if I have to replace the fill valve. We'll know pretty fast if that's what I need to do if the slow leak is still there after I put it back together.

    I've seen people or heard of people having three issues.

    1) Can't get the fill valve to seal at the tank.

    2) Can't get the steel supply line with the head on it to seal right.

    3) Tighten it too much and crack the tank!!! I'm most worried about this one!

    The red washer on the fill valve looks like "newer technology" than in the past, and i'm wondering if that makes getting a good seal easier.

    Also, how tight roughly is what you want? Are we talking hand tight?

    The steel supply line on mine looks like it's not going into the bottom of the fill valve very straight, it looks "cocked". Yet it still seems to seal great for 6-7 years.

    I know that the flex hose lines are much easier to deal with, but I also know once you get steel right it never bursts or leaks or wears out like flex hoses can.

    I'm going up now for more surgery, but any thoughts on the above will really help. Terry thanks for explaining that you recommend the cap but never the fill valve for an "amateur", I'd love to hear more on why...

    Lee
  19. lee_leses

    lee_leses Member

    Messages:
    54
    Location:
    Pennsylvania
    Well, here's the latest:

    I took the valve apart AGAIN (lol), and this time I put in a new float with a new pilot seal. I also put in a new top part of the fill tube, the part shown in the second picture that the white plastic filter slides up into. As you can see in the third picture, which shows the old float and pilot seal, there is a deep impression in the seal that is not in a new one. So I reassembled the whole thing, and unfortunately it was audibly leaking when it shut off, and filling up to the overflow tube much faster than before. So I had to R & R the whole valve, which I'll talk about below. However, I think it's important to mention that people at Korky said that sometimes it is the pilot seal does cause a slow leak that can be fixed by taking it out and turning it over.

    So I ended up taking out the entire valve and replacing it. When I took out the old valve, I set the old one and the new one side by side, and made sure to adjust the new valve to the same height as the old one, then I locked it with the white tab. The white tab is locked in right when it's in and two holes in the tab are showing. For those who are super anal like I am, I reused the original blue cover that says "G-Max" on it, the blue cover on the replacement valve says "Korky." (Yeah, I know I'm super anal, LOL.) So then I put the whole thing back together again. I found out that they use a new black plastic tank nut that's easier to hand tighten than the old white plastic one that's made to fit a wrench with a hex shape. There wasn't a metal head on the steel supply line like a faucet like I thought, it's a rubber cone seal. So I hand tightened the tank/mounting nut and then the coupling nut that tightens down on the cone seal. I put the fill tube back on and filled the tank, and for two hours so far the water is staying the 1/2" below the fill tube! So far, the hand tightened nuts seem to have sealed perfectly. When I took the old white nut off, I had to grab it with a channel lock pliers and turn it maybe 1/8th of a turn before it would come off by hand.

    So, after taking apart the old valve and inspecting it, I noticed the following things. The tank washer/seal and the cone seal are made of the red color rubber now, the old washers and seals were made of black rubber. Maybe the new red rubber parts are made of the same material as the Toto 3" flapper that's supposed to be more chlorine resistant? The slots/holes in the chamber that holds the float are in different spots on the new valve, this does not seem to make much difference at all. The old flow restrictor was white, not blue like the new one in the first picture. The old flow restrictor is shown in the third picture. I looked closely at the old "O" ring, thinking for sure that was the cause of the slow leak. I can't find anything wrong with the old "O" ring. The black plastic on the valve body seems like it's more brittle than when it was new. When I tried to take it apart to try to find the cause of the leak, the two tabs that hold the bottom of it snapped right off real easy. Note the two red arrows in the third picture that show where the tabs used to be. I'm wondering if it's the chlorine that weakens the plastic over time? I pried on the plastic tabs on both the new 528 and the new 528T, and none of the new tabs broke off easy like that. Since I put in a new top part of the fill tube, and the "O" ring looks okay, I suspect there's a tiny crack somewhere on the bottom part of the fill tube, the part with the tabs, the red washer, and the threads. The only fix for that is a new fill valve.

    So, in the end, I can't find where the leak is in the old valve. I *think* that when I disturbed it maybe the "O" ring refused to seal right again, or it's very possible that the fill tube plastic was so brittle that a tiny crack is in it someplace. I will say for all those having the same problem with the 528 valve should be as gentle as possible when taking the valve apart, and be very gentle when putting the top part of the fill tube/white filter when you try to push it back into the bottom part of the telescoping fill tube. If the valve still has a slow leak, think about if you're up to replacing it yourself! You have to have the natural plumbing gene that you either have or don't have...

    I’m sorry this got so long! But I’m a big believer in maybe this will help someone else, and you always need information and help when it’s NOT Monday – Friday during the day. LOL

    [​IMG]

    http://home.earthlink.net/~lee_leses/528

    Does anyone know why when I try to insert the url so the pictures will show in the post all I get is the little red "X" ?
    Last edited by a moderator: Jan 11, 2009
  20. Probedude

    Probedude New Member

    Messages:
    137
    Location:
    CA
    Terry's forum doesn't allow putting URL's in the text.

    That dimple in the float's rubber disc is expected - if you look at where it touches you'll see a port that is bumped. Over time it deforms the rubber.

    So you're all fixed up now?
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