Third Level Spray Arm

The lower spray arm unscrews. From inside the dishwahser, put a screwdriver through the tab slots and unscrew the tower from the floor. It's pretty tight for plastic.
The upper spray arm has screws on the top of the dishwasher. You must slide the dishwasher out from underneath the countertop to get to the screws. Normally that's just the two screws above the door that screw into the countertop. Pull the insulation back and unscrew the arm from the top of the dishwasher. Reverse to reinstall.
Piston and nut assembly for check valve: Inside the dishwasher at the back there are 2 screws that hold a screen down. Remove the screen. Take out the check valve and replace it. It was still functional in mine, it looked like food gunk had built up on it and impeded the check valve action.
The flapper chec is a rubber flap in the drain tube that connects to your sink drain. You have to pull the dishwasher out from under the sink to get to the end of the drain tube that connects to the dishwasher. Take the hose clamp loose and remove the drain tube from the dishwasher. Then unscrew the plastic fitting that you just took the drain tube off of. The flapper chec is there. It had turned brittle and didn't flap anymore. It is a similar setup to the rubber seal at the end of your garden hose.

As suggested. Pull washer, remove screws from top and replace with new part. Very simple and easy if you follow steps furnished by this site.

Pulled unit out of cabinet took two top screws out of spinner spray arm and put back together.Old sprayer was plugged up not letting wash go through.Thanks for helping me fix and not replace unit.Saved at least 400.

Turn off power at breaker box.
Remove lower covers and 2 screws into counter top.
Verify sufficient length on water and electrical connection to allow sliding dishwasher out approx. 2/3. I disconnected the electrical at the j box on the dishwasher. If you must disconnect the water line, shut off supply, usually located under nearby sink, and provide a rag or sponge for small amounts of water left in supply line.
Carefully pull back the insulation to expose two screws on top where water line runs into the center.
Pull the top tray part way out and reach in to hold the spray arm while removing the screws. The spray arm will easily drop out.
Hold the new spray arm in place making sure the raised screw posts push into the holes, then reinstall the two screws. Done. Pull insulation back into place, retape if necessary. Reconnect electrical and water if necessary.
Slide unit back in, checking alinement. Rescrew to counter top and reinstall lower covers. Task complete. 15 mins if prepared. 30 mins if both elect. & water are disconnected and you are somewhat hesitant.

Without any specific directions with the part (which would had been nice. If it wasn't for my husband I wouldn't have known where to start.) I had to carfully pull the dishwasher out of the cabinet (it wasn't heavy) to unplug the power supply. Then we unscrewed 2 screws on the top and the upper arm connection came off. We replaced it with the new one, screwed it back on, reconnected the power supply and pushed the dishwasher back where it belonged. It worked out very well.
Also I want to say I am very happy with the length of time it took to get my part to me. (1 day) I was washing dishes it no time.

Thank You
Debbie Bradford
Hookstown, Pa.

Used a nutdriver to remove the two screws attaching the third level spray arm and a pliers to release the clamp holding the power shower hose. Reversed the process on the new hose and spray arm. Dishwasher works great now!

replaced hose and upper sparay arm