Dishwashers have hoses, and after time, if the connections get loose or become brittle or cracked, they can leak. The rubber gasket around the dishwasher door also may become worn out and loose, and then it has to be replaced. When there’s a leak, first look at the rubber gasket. It could simply be out of place. If it’s not, then make certain that all the hoses are clamped tightly and aren’t damaged. If you find one that’s brittle or cracked, replace it.
Pumps on older dishwashers require you to rinse and scrap plates and utensils before washing them; otherwise you’d gum up the pump. Pumps on some recently manufactured dishwashers need those scraps and grease to lubricate them. If you have one of these dishwashers and still clean everything before you load it, your pump will burn out. So read the owner's manual before you do great harm.
Some dishwashers have an air gap (a valve) on the drain line at the back of the sink between the faucet and dishwasher. It can get clogged, and that affects the performance of the dishwasher. To clear it, you need a screwdriver and tweezers. Air gaps aren't used much in new dishwashers.
To maintain your dishwasher, you may need to clean your air gap valve, the spray arm, and filter. Here’s what to do:
Pull off the drain tube air gap cover and unscrew the plastic cover underneath.
You can identify the air gap because it has a chrome cover.
Use your tweezers to clean out the tube.
Clean the cap and cover if they’re dirty.
Replace the cap and cover and then remove the lower rack by sliding it out.
If you see a plastic hubcap (cover) on top of the arm, unscrew it by hand. If there isn’t one, go to the next step.
Take the arm off.
If your dishwasher has a removable strainer and filter, take it out.
Poke the wire through the holes in the spray arm to clear them.
If the dishwasher doesn’t drain, the screen in the bottom, inside the dishwasher usually needs to be cleaned. If that doesn’t end the problem, call for service.
Wash the strainer and filter with a brush.
When you run the dishwasher, be sure to use hot water; otherwise you won’t get clean dishes. Your water heater should be set at 120 degrees. And before starting the dishwasher, run the hot water faucet for a couple minutes. That will get hot water to the dishwasher right away.
Rinse the arm strainer and filter and reinstall them.
Many dishwasher parts are replaceable, including the pump, hoses, and motor. But you have to pull out the dishwasher and tip it over to get at them, so call for service.
Use the wire to remove debris from the holes in the spray arm at the top of the dishwasher.
This may call for a contortionist, but don’t try to remove the arm.