I have the AS 4251 Standard Collection Kitchen faucet. The water barely trickles out. It has been getting worse and worse. The aeretor is not dirty, I have the same flow with the aeretor removed. I removed a supply line and ran it into a bucket and I have great flow there. The rest of the house has normal good pressure and flow.

mixing valve and ceramic washers are defective. American Standard is not what it used to be. Parts are substandard and imported from china. Get yourself a Glacier Bay, and contact American Standard and demand your money back or a credit.

There are several of things that could cause that but the first thing I would do is unscrew the little screen thing at the tip of the faucet.
If you then get good flow, clean it and put it back on.

water flow on my kitchen faucet is very low YouTube

Contact A/S via web site they will probably send you a new diverter free if you raise enough stink about having this problem and you would just buy another brand faucet.

Hello
Here is a link to american standard,I could not find your model.Most lowes or home depot stores have a replacement cartridge.


http://www.americanstandard-us.com/assets/documents/amstd/parts/Parts_1395.pdf

Just shut off your incoming water before you take it apart.Usually you will need a pair of pliers a phillips screw driver and a set of allen wrenches.

I f like most faucets it will have a aerator its at the end of the spout unscrew & clean...that should do the trick ';';';

If you have properly replaced the diverter assembly, there is either a problem with valve or debris was left in the valve from old diverter when new diverter was installed. Disassemble diverter by pulling spout back off. remove new diverter and check valve. Cup your hand over faucet and turn cold water handle on to attempt to flush any debris left behind. Try several times then reassemble. If this doesn't do the trick then replace. Get a quality filtering system and take care of your new faucet by making sure it's dry and polished after use. You won't be replacing your fixtures as often from calcium and corrosion.

I had the same problem. You need a "diverter" (044264-0070A). It's available directly from American Standard at no charge. Lifetime guarantee! Phone: 1-800-442-1902.

I would check take apart the cold flex connector and check the flow when running water into a bucket, if it is wimpy then there is a blockage in the angle stop or the flex connector. If it is good you will need to take the cartridge out, check for signs of debris and possibly replace it

Usually debris is blocking the way. Turn off valves, remove lines and clear the way.

Shut off the water. Use an allen wernch to remove the control lever. If there's a cartridge, remove the clip at the top. If there's a ball, unscrew the ring that holds it in place.