Kohler style k12172 fairfax when i use the side spray there is very little pressure & the hose and sprayer are new and the hose has no bends in it.

Under the sink there is a pressure valve

Hi! Yes it sounds like the spray diverter needs replacing. Kohler .com will have this part online or you could try a plumbing supply shop.

yes any bend not made properly will affect the flow also makes a week spot.

Go to kohler web site and request a parts break down of that model they should be able to e-mail you a diagram and provide parts needed at little or no cost if you are firm about not using their product again because of bad experience with this faucet.

Kohler K-79402-CP aerator kit
Kohler K-78250
Kohler 1001100
You might try to replace aerator on end of spout if water is leaking around it, or you might try to replace cartridge. VALVE (CORALAIS AND FAIRFAX)
K-GP77548
$14.80 List Price

Call Kohler if you need more info.

First thing to check is if it has a strainer on the spout that has debris. The second thing is if you have a sprayer attachment the diverter valve is a chronic problem with kitchen faucets.

I had the same problem and had to take apart the handle portion and found that there was something in the line at that point. After cleaning it I had the same pressurse as when it was new.

Are you sure it's not just that the shower heads are getting dirty from calcium build up, thus reducing the diameter of the holes in the head, which will in turn cause spray to come out at higher pressure. ( same idea as holding your thumb over the end of a garden hose) Try removing and either replacing head, or soak it overnight in C.L.R (available at any hardware store.) and clean it good and try it again.

Verify the cold water outlet has equal pressure as the hot side outlet at the wall. Check the inlet screen on the cold side water line where it attatches to cold water pipe. The screen could be plugged. Then check the cold side hose for any restrictions. Also check if there is a screen on the outlet side of the cold water hose and see if it is plugged. Otherwise the faucet valve is mis-aligned and will need to be rotated and re-tightened to align the valve to the center so both sides have equal water flow.

it sounds like it's cloged with sedement or somthing. try disconnecting it and cleaning it