Apparent flow blockage

American Standard has an on-line Repair Parts centre:

http://www.americanstandard-us.com/store/repair-parts/

Hi,
Take the handle off (set screw underneath)
Then turn the top off under the handle....make sure water is off...
then you will find a ball with the handle stem on it....note the position of it and pull it out...
under there are two wets of springs and rubber seats...
pull the right side out and check the hole for a blockage...(dirt or rust)
if none is visible, you may have to unhook the cold water supply hose
and then blow compressed air back through the hole to remove the blockage...
then reassemble...

heatman101

It says you have a problem with the hot water. First thing to do is to turn the hot water supply valve under the sink off, and then remove the line from the valve to the faucet at the valve. Then put a bucket underneath the valve and turn it on (carefully). If you don't get any flow, then the problem is in the valve or the pipes supplying the faucet. If you get flow there, then the problem is in the supply line or possibly at the faucet.

What is likely happening is a small piece of sediment has become lodged in either the mixing valve or in the aerator.

Begin with the easiest part first. The aerator is the threaded attachment from which the water comes out of the faucet. Remove the aerator from the faucet and run the tap without it installed. If the flow rate is good either clean or replace the aerator.

If this was not the problem then the solution becomes much trickier because the obstruction is likely in one of the lines coming into the faucet or in the body of the faucet called the mixing valve. This is where the hot and cold water mix inside the faucet.

Our next step is to create negative pressure inside the faucet in an attempt to remove the buildup restricting the flow.

If you don't have shut off valves under the sink you will need to shut off the water supply to the home, remove the faucet from the vanity/sink and perform the following procedure.

Shut the hot and cold water off underneath the sink and remove the supply lines at the shut off valves but leave them connected to the faucet. You will need to purchase two adapters for the aerator that will allow you to connect a garden hose from your closest water supply (kitchen sink) to the vanity faucet. You can find these at your local hardware store. You will also need a pail under the vanity to catch the water coming out of the vanity faucet supply lines. Connect the garden hose from an active water supply to the vanity faucet. With someones help have them turn the water supply on which will then run backwards through the vanity faucet and into the pail underneath the vanity. Be sure to open the vanity faucet taps to full so that water will run through the faucet. This should dislodge the obstruction.

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

go to home improvement store and buy mixing valve for that model

replace the faucet,sounds like it has gone bad.

if this is the faucet in picture, turn off water, pull out cartridge and inspect for any debris in cartridge or valve body, if not, turn on hot water to see if water is getting through valve body. May have kinked line or debris from or in angle stop line.

Not the aerator at all as this part would act the same if hot or cold.

Have you checked the shut-off valves under the sink? Sometimes just turning them a bit in either direction will solve that problem (will only be the case if it have been shut off at the valve recently).

Also, maybe the supply line on the hot side have been kinked?

Hope this helps

The faucet cartridge is more then likely blocked and the faucet will have to be disassembled in order to unblock it.
While it is disassembled you should slowly turn on the water lines to make sure the water ways in the faucet are clear. And thoroughly check the cartridge for damage. Replace if necessary.
Replacement Cartridges can be purchased at most plumbing supply houses or Big Box Stores such as Lowes or the like.