Fluidmaster 400A Perfomax leaking a bit - replaced the O-ring

[y_p_w]

I had an issue with one that wouldn't stop hissing and filling even when the float was at the top and I was sure it was fine. Once it got to the top it slowed down but still hissed. Looked inside, and there's this little O-ring that seals off the inside of the shank where it slides to adjusts height. It broke (might have just been old or I previously adjusted it where I broke it). I might have been able to reuse the O-ring from an older 400A but have since tossed the old ones that I replaced.

My wife was hoping I could fix it quickly and got to a hardware store before it closed. I showed them the shank with the broken O-ring and they first went to a box behind the front counter where they kept various O-rings. One looked like it might fit but was too small. They advised to look for the packaged O-rings in some sliding displays and the closest I could find was a Danco #5 (3/8" O.D., 1/4" I.D.) O-ring that seemed to be close enough for 69 cents. When I got home I tried slipping it on, where it did take a bit of effort. It didn't seem like a perfect fit, but good enough to seal the surface. After a bit of adjustment and a few issues where the valve wasn't filling the tank, it seems to fill now and stop immediately when the float reaches the set height.

Is this likely to be a long-term fix? It doesn't seem quite as wide as the old one I replaced, but I'm thinking that it might have been compressed from its original shape from being there for several years.

 

[y_p_w]

Just looked up the O-ring and Danco sells them to replace faucet seals. But if it works, it works.

https://www.danco.com/product/5-o-ring-10-per-card/​

• Designed for use on Price Pfister, Kohler, Wallaceburg and Waltec faucets
• #5 O-Ring (AS568B# 010)
• 3/8 in. OD x 1/4 in. x ID x 1/16 in. wall thickness

 

[CarLuver]

For $8 i don't even bother to fix. replace one in 15 mins . the clorine in my area eats the rubber after a few years

 

[Lubener]

Just buy and install a new 400A and be done with it. It's not worth messing with the seal.

 

[y_p_w]

Just buy and install a new 400A and be done with it. It's not worth messing with the seal.

They sell the 242 seal although the price varies. I think the last time I got one for less than $2 and some plumbing supply houses sell them really cheap in bulk. But in this case I was in a hurry and the local hardware store was the closest. A new Performax is $15.

https://www.homedepot.com/p/Fluidma...ance-Toilet-Fill-Valve-400H-002-P10/305719514

 

[y_p_w]

For $8 i don't even bother to fix. replace one in 15 mins . the clorine in my area eats the rubber after a few years

I'm OK with the 400A, but I know a lot of plumbers prefer the Korky QuietFill Platinum. If I had to replace it I would probably just get that since it's cheaper than the PerforMAX equivalent and works about as well. Also a fair bit easier to install although replacing the seal is a bit different than on a 400A. It doesn't have a knob microadjustment, but it's easier to adjust the height in place if the locking clip isn't inserted.

I replaced a malfunctioning 400A in a rental house a few months ago. Wasn't sure what the issue was, but it was a factory installed 400A (with a restrictor plug in the tank fill outlet) and the tenant just shut it off and took it apart. I did have a bear of a time removing the hex nut at the bottom. Got a QuietFill Platinum to place it and when I came back later the tenant said that it made less noise and filled the tank a lot faster.

I do prefer the wing nuts on aftermarket replacements. Not sure what's the deal with OEM fill valves using hex nuts.

 

[Wireman1987]

You could replace a fluid master fill valve easy in as little as 2-3 mins. Turn off supply, slide up height adjustment lock collar, pull the valve straight off drop the top half of the new valve on, adjust your height and lock the collar down. Working hotel maintenance you learn to work quick get in and get out even faster.

 

[Nessism1]

Korky QuietFill Platinum is $10 shipped from Amazon. When one part is failing on a toilet valve, others are likely close behind. It's not worth the hassle to do a piecemeal repair.

 

[Wireman1987]

Wolverine brass makes a nice fill valve

 

[y_p_w]

You could replace a fluid master fill valve easy in as little as 2-3 mins. Turn off supply, slide up height adjustment lock collar, pull the valve straight off drop the top half of the new valve on, adjust your height and lock the collar down. Working hotel maintenance you learn to work quick get in and get out even faster.

I’ve researched this where some plumbers and handymen do just keep the shank in place and then have a supply of shanks and washers as spares. Didn’t think about it it before.

So I suppose hotels like the 400A because of this. And the PerforMAX should have the same shank.

Ever installed a restrictor? I placed pinch roller tube once, but I didn’t notice the fixed restrictor plug that was sized for the toilet.

 

[Wireman1987]

About a month ago replaced a 400A for my father with the performax kit swapped exactly the same. No never messed with fixed restrictors just the one like you mentioned roller and the performax

 

[CarLuver]

the restrictor slow down the flow thus quiets the filling . i actually did a noise test with 2 fill valves . one with the restrictor and one removed . the non restrictor was noticably more louder.

whenever i do these now i use the korky one . they seem to last longer and quieter

 

[y_p_w]

the restrictor slow down the flow thus quiets the filling . i actually did a noise test with 2 fill valves . one with the restrictor and one removed . the non restrictor was noticably more louder.

whenever i do these now i use the korky one . they seem to last longer and quieter

I'm rather agnostic about brand. They have their strengths and weaknesses. Some like Korky because they're still American made. Some love Fluidmaster because they're easier to fix rather than replace completely. I totally get how replacing the innards of the Fluidmaster 400A is much easier, especially just keeping the shank (which rarely fails) in place and replacing the rest. But Korky is cheaper.

I like the Korky QuietFill because the fill line is right there on the top of the valve. For the 400A it's mounted with the cap set about 3 inches over the top of the fill line, but then a fine adjustment can be made.

And there are so many different versions of the 400A including some OEM versions made for Kohler. I've heard some pros prefer the brass shank versions because they're less likely to break.