Cold pressure changes in Moen cartridge faucet

[chatko]

Hi,

I've got a single handle "Cartridge" Moen kitchen faucet (unsure of model number, its been installed for two years.)

For awhile now we've had problems with the cold water. When i turn it on full it flows fine for 20sec and after that it slows down to 1/2-1/3 of the full flow rate.

Hot water doesn't seem effected. Cold water in other parts of the home works just fine. Additionally, the shutoff valve for the cold is open to full.

I've opened the faucet up, taken out all parts, lubricated and reassembled (there was no obvious warn part to my untrained eye).

Any ideas?

Thanks

[Herk]

It's hard to say what the problem might be. But it could be something like a rock or small metal part in the body of the faucet. It seems unlikely that the diverter (assuming there is one) would be closing with the spray not being used, but the body of Moen kitchens can be plugged easily - there are inner chambers with very small passageways and it's impossible to clean them. In that case, a new faucet would be in order.

[jadnashua]

It could be in the supply shutoff valve at the wall if it is a multi-turn one with a washer rather than a 1/4-turn ball valve. Sometimes when the washer gets older, it can swell, or crack, or other things that can restrict the flow. Try removing the hose and then running the output to a pail or something.