To proceed with this repair you must shut off the water source that supply this product. For details see How To Shut Off The Water Supply
Due to the issue you are experiencing, the valve body must be cleaned and flushed before installing the new cartridge.
- Clean the inside of the valve body with a soft bristled nylon brush (e.g. old toothbrush), to remove any mineral buildup.
- Hold a bowl or similar object over the top of the valve to help direct the flow of water in the next step.
- Briefly turn on only the water supply line for the side experiencing a low flow of water issue. This will flush clean water through the open valve of the afflicted side. This will take the debris causing the low flow condition and push it out of the unit. This will send a lot of water through the open valve. Use bowls or similar devices to redirect water from the open valve back to the sink.