Noisy Water Pump Fix

Spruce1

Tonight I installed an accumulator tank in an attempt to quiet our noisy water pump in our 2014 S Max.  After the install I tested the system and found the results mixed.  The bummer is that the pump still makes the thumping sound but it does seems to be somewhat quieter now that the tank is installed.  On the plus side, what I'm very pleased with is that the pump no longer makes the loud clanging sound just before it shuts off.  Overall I'm pleased with the outcome.  The tank is a SHURflo model 182-200.  It was about $40.  The photos below show how it connects to the pump and the rest of the system.  About 15 minutes to install.  Only dropped one screw down behind the wall.

Ratkity

Looks good! I read in the insert for the pump in my package of warranty things that the rubber feet are supposed to reduce vibration and they shouldn't be torqued down as tight as the screws can go. I loosened the screws on mine a wee bit (they still tightly hold the pump) and the loud water pump quieted down considerably. 

drazilgod

I was pretty obsessed about the whole noise thing for a while. I too bought and installed that accumulator. I too had mixed results. I eventually realized that most of the sound I was hearing was transmitted through the piping and pipe contact with walls. So I bought 2 20 inch FIP hoses, wrapped them in soft foam insulation, replaced the OEM short white hoses, and I was able to drop the pump and accumulator tank off its mounting, down about a foot into that cavity. Then I gently and very loosely packed about 50 square feet of small bubble wrap around the pump, accumulator and piping, making sure that there are no kinks in the pipes and that there is no contact between the pump system itself or any wall. I finished it off with some closed cell foam which makes a storage shelf in the hatch area, where the pump used to be. According to my noise level app, the sound went from about 50 dB to just below 40 dB. Is it silent, well, almost. But the accumulator stores water pressure for a late night hand wash (with pump switch off) and I have a nice new storage area. I'll put a thermometer on the pump after a shower one day as my method definitely restricts airflow, but other than that concern, I'm very happy with the results. The pump is much quieter. You can't hear it over the faucet.
Footnote: I just noticed in the second photo from @Spruce1, the left pipe is wrapped with black foam insulation. Our 2018 Max did not have that from the factory, but that is what I think is key to noise reduction.

Verna

I slid a 12” section of pool noodle around the left pipe that was touching the shower wall inside the cavity. My noise is now less than half of what it once was....just going by my ear comfort. 

But, if I let the water level go below what the pump can pump out of the fresh water tank, the noise level goes back up to the original until the pump is totally primed, and then the noise level goes back down. 

Just in case, it’s nice to have 5 gallons or so of fresh water in a jug, or jugs, ready to be transferred into the fresh water tank. 

Spruce1

Yes, I first wrapped the pipe with black foam insulation.  That was done to stop the plastic pipe from banging against the wall.  That fixed one noisy problem. I then added the accumulator. As mentioned in my original post that helped somewhat and like drazilgod it's nice to turn off the pump at night and use the accumulated water!   After reading Ratkity's post I loosened the screws that attach the pump to the wood bracket (just enough to give the rubber gasket a bit more "spring") and that helped a bit too... going by ear.  May have to try lowering the pump.  Silence and extra storage!!