HELP - toilet flush makes noises like jackhammer

Nestor_Kelebay · 09-09-2009, 08:34 PM

Normally you shouldn't need plumber's putty anywhere.

Normally, the new rubber grommet that comes with the new flush valve will seal against the bottom of the toilet well. If you tighten the plastic nut, it will pull the fill valve down and the rubber grommet will create a water tight seal at the base of the fill valve.

What often happens is that if you have a plastic tube (called a "flexitube") between the water shut off valve and the fill valve, then when you replace the fill valve, the plastic end of the flexitube won't conform to the new fill valve right away, and it'll leak.

You can generally solve that problem by replacing that plastic tube with one of those braided stainless steel supply hoses. They cost about 7 or 8 dollars, but they work well and are re-usable many times over.

Exactly where is the water leaking from?

Redwood · 09-10-2009, 06:27 AM

Have a look at this link especially the pic at the bottom of the post.

How to Replace your Toilet Fill Valve with a Fluidmaster 400A

Make sure that the rubber washer is installed on the fill valve shank as pictured.

Speedbump · 09-10-2009, 09:25 AM

Quote:

t is crazy -- the noise only happens late at night -- and it doesn't happen every time -- and it doesn't happen at the start of the fill cycle, it happens when you're on the other side of the room washing hands a good 15-20 seconds after making the flush... Any thoughts?

Sounds like the valve trying to shut off and the seat itself is hammering from too much pressure in your lines. This same thing can happen to an Autotrol Water Softener head if you raise the pressure beyond 70 psi. The valve tries to close and it gets to pulsating back and forth very fast and causes an awful noise. Since water cannot be compressed (which sort of disputes Nestors theory of the people in the bus going forward) it hammers to a stop, backs up and comes forward again at a high rate of speed.

Nestor_Kelebay · 09-10-2009, 10:45 PM

Just cuz water is incompressible, don't mean it doesn't have momentum. When you shut a valve quickly, the momentum of the water upstream of that valve has to go somewhere. It can't just disappear cuz energy can't be destroyed. It just gets converted to another form.

Speedbump · 09-11-2009, 06:42 AM

Quote:

It just gets converted to another form.

Steam maybe???

JALEXED2 · 09-11-2009, 07:53 AM

Jennebelle - since your last posting after you replaced the ballcock, you did not indicate if the noise continued. You indicated a leak from the bottom of the tank but didn't comment on the noise. Could you please update your findings?

Also, you indicated the noise was a good 15-20 seconds after the valve shutoff. That's interesting since I have generally only noticed water hammer once the valves are shutoff and the noise happens immediately.

jennebelle · 09-11-2009, 08:08 AM

We installed the fill valve in accordance w/ the instructions, including placement of the rubber washer, and it is functioning appropriately. We also understand that we should not have to use plumbers putty; however, we have a slow drip where the valve shank connects to the water supply. When we disconnected the original fill valve it was clear that when the toilet was installed our developer used plumbers putty to connect the water supply to the fill valve. We had not considered replacing the water supply tube w/ the braided stainless steal closet supply tube.

which do you recommend? replacing the supply tube? using plumbers putty? both? or something all together different

jennebelle · 09-11-2009, 08:11 AM

we replaced the ballcock mid-day, when the noise doesn't typically occur. due to the leak, we started using other toilets and have not tried during evening. actually, last three times we had noise before replacement the sound started as late as 40 seconds post-flush.

inspectorD · 09-11-2009, 02:54 PM

If you have a 40 second delay...you have water hammer in the pipe. The toilet tank finishes filling and shuts off the water to the tank. The abrubt stop of water causes a bang on the pipes which is the cause of the noise.
Go the the local plumbing supplu house and tell them what you have, and the size of the piping to the shutoff valve.
Or call a plumber.