Thank you for your question, and I am sorry to hear that you are experiencing low flow from your Delta faucet. You may need to flush out the valve body. To flush out the valve body, first turn off the water supply to the faucet.
1. Remove the handle. On the lever handle, you should find a small hex screw that can be loosened with a 3/32" Allen wrench. The handle will lift off when this screw is loose enough.
2. Once the handle has been removed, unscrew the dome-shaped cap. The domed shaped cap will unscrew counter-clockwise.
3. Unscrew the bonnet nut under the cap.
4. After these parts have been removed, you can then pull the valve cartridge assembly straight out.
5. Now, with the valve completely disassembled, place a bucket upside down over the top of the empty brass valve body. Turn the hot and cold water supplies back on and let the water run for about 10 to 15 seconds. The water will come directly up out of the valve and should mostly be deflected back into the sink by the bucket. You might have a little bit of water to clean up, though!
6. Shut off the water supplies. Make sure that the valve cartridge assembly does not have any debris stuck to them and reinstall them. Reinstall the valve cartridge assembly. Reinstall all parts. At this point, you can test the faucet again.
If this does not fix the issue, please contact our Delta Customer Service line at (800)345-3358. We are available Monday-Friday, 7am-7pm, CST and Saturday, 8am-5pm, CST. You may also email at firstname.lastname@example.org.
Date published: 2018-04-04