Does your toilet valve shudder when adding water?

[Snowman9000]

Our Dometic 310 porcelain toilets foot pedal fill valve has always been finicky when we added water to the bowl. It shudders and is jumpy. Read on for the fix.

Apparently from the factory the valve is only held in place by its two clips. The replacement valves come with two screws which make it more secure. The screws eliminated the shuddering, and now it works smoothly. I could only get the top screw in place, but that did the trick.

You don't need a new valve, just the screws.

You can see the upper left screw at the 55 second mark in this video. The other screw in the lower right is not visible.
https://youtu.be/JSrHyIRRG50
You might use a mirror to see the empty slots and holes on yours.

Best guess, the screw is a #6 sheet metal screw. It measures 1/8 od including threads. Length 9/16, but 1/2 will be plenty long.

[Snowman9000]

The clips keep it fixed well enough that it doesn't leak, but can wiggle. The wiggle causes the shudder. The screws stop that. I only installed one screw, the top one.

[Dave_H_M]

thanks for the update Snowman.

I got the info printed out and will get it done before next hook up.

[Snowman9000]

No, I am saying to install one or both of the missing screws. Keep the existing valve.

I just added that to the first post. Sorry for the confusion.

[Dave_H_M]

Mine shudders like crazy in the fill mode.

So are you indicating that ordering a replacement valve from any source will fix it?

oops, OP indicates that will do the trick. :C

[Snowman9000]

Also, I suspect this toilet uses more water than the older designs. Maybe a cup per flush, just guessing. Only a problem for dry campers. But it does flush well, so....

[Snowman9000]

If you add one or both screws, let us know if it fixes it. For all I know it may have been the cause of the run-on pulses we discussed in the other thread. I put in a new valve so I can't be sure. But the first two valves were not screwed down, and they both shuddered. (I had to replace the first one due to freezing damage.)

[2oldman]

Thanks.. yes mine shudders.