# About Flowmaster Quick-Install 400A Fill Valve **URL:** \ **Category:** In My Humble Opinion\ **Created:** [July 1, 2025, 12:06am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323 "2025-07-01T00:06:41Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [July 1, 2025, 12:06am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323/1 "2025-07-01T00:06:41Z")
Many amateur and professional plumbers may be familiar with the Flowmaster (Quick Install) 400A Fill Valve which is like an all-in-one, once and done fill valve sold at Walmart and all hardware stores. It is very common and easy to use, but! Like everything, they changed it for the worse. Before I even start, I notice a white plastic piece just inside the mouth of the gray intake tube (about 1-in up inside) where the supply line connects to the intake tube. This white piece blocks like 99% of the intake tube. The instructions say nothing about it (of course). What is this? Should it come out? Can I take it out? It’s not made for easy access, but one could jam a scratch awl or a screwdriver in there and clear most of it out. Why do companies do such stupid things? (Aside: Honda put a small, plastic filter (like the shape of a target) just inside the mouth of where the oil goes. It blocks the use of a funnel. I could break it, but the shrapnel would drop deep down into the tube to who knows where. 🥵 I’'ve had four of these vehicles…I know it’s there just to piss me off.) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 1, 2025, 12:37am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323/2 "2025-07-01T00:37:12Z")
It’s a flow restrictor, grab it with a pliers and pull it out if you don’t want it. > **[Fluidmaster Flush Valve fill extremely slow (built in flow restrictor).](https://terrylove.com/forums/index.php?threads%2Ffluidmaster-flush-valve-fill-extremely-slow-built-in-flow-restrictor.101372%2F)** > > Just like to pass on some information. Today at my son's house I replaced the diaphragm on a Fluidmaster 400A flush valve. It was taking about 5 minutes to fill the tank for water was barely flowing. The diaphragm was not the issue. I then tried a... [![](https://terrylove.com/forums/index.php?attachments/img_6268-jpg.86409/) ](https://terrylove.com/forums/index.php?attachments/img_6268-jpg.86409/) ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [July 1, 2025, 12:41am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323/3 "2025-07-01T00:41:21Z")
Fluidmaster even gives directions for removing it: > **[How to remove the toilet fill valve flow regulator](https://www.fluidmaster.com/toilet-problems/remove-toilet-fill-valve-flow-regulator/)** > > Fluidmaster shows you the instruction for removing the flow regulator from our PerforMax Fill Valves. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [July 1, 2025, 2:32am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323/4 "2025-07-01T02:32:11Z")
Clicking on your link, the key line is the last line supporting my complpaint: The 400A instructions makes no mention of it. ---
**Author:** ![Jinx](https://avatars.discourse-cdn.com/v4/letter/j/c6cbf5/32.png) [@Jinx](https://boards.straightdope.com/u/Jinx)\ **Post date:** [July 1, 2025, 2:34am UTC](https://boards.straightdope.com/t/about-flowmaster-quick-install-400a-fill-valve/1020323/5 "2025-07-01T02:34:04Z")
So, bottom line? It sounds like I should try it first. The advantage is that it cuts down on a noisy flow and possible water hammer. The drawback is a slow fill. Never had a problem before. If it ain’t broke..