O-Ring

Remove sides, back, top and front control panel following video on eReplacementparts.com web site. Remove clips where tubes connect to generator and other interior machine parts, remove tube, remove old o-ring, replace with new o-ring, replace clips. Reassemble.

I unplugged the machine and removed the water tank and water tank cover. Then, I unscrewed the two screws on top of the machine holding the main covers in place, and carefully pried the steam knob off. After that, taking the cover off the unit is a little tricky. There's a tab in the back that locks it into place and takes some finesse to not break while trying to take the cover off.

Once it's off however, I located the tube running from the water pump to the heating element, removed the alligator clip holding it in place, and carefully pulled the tube free from the connector. I had to fish the o ring out from the connector with a toothpick, but it was relatively easy. I then slipped the new o ring over the tube, re-inserted the tube very firmly into the connector, locked it in place with the alligator clip, and tested the machine for leaks. Once confident that the leaks were solved, I replaced the cover, steam knob, etc and screwed everything back into place.

Overall a very simple repair, just take your time and make sure to use common sense.

Identified section leaking
Tried several combinations of gaskets and O rings and finally stopped the leak

Remove screws on the back of the espresso machine
Remove the rear cover panel
Slide the side cover panels to remove
Remove screws and the top cover
Remove the tube ends and replace each washer, refer to the part drawing from the website
Put the top over back and test for any leaking
Put the side and then rear panels back

Done

The hardest part was reaching three screws which secure the top of the machine. It requires a star drive. All of the other screws are small Phillips heads. After you remove those and two on the back, the top will lift right off.

I promise, everything is very intuitive. Unplug the hoses by simply pulling on them, remove the pump by wiggling it off its rubber mounts and unscrew the water valve connected to the pump the pump. Replace those with the new ones and reverse the process.

I chose to change a few of the other little pieces of tubing, simply because I was under the covers - super simple and cheap.

I also replaced the spring and valve on the head (where the water comes out) to ensure that the new pump didn't overwhelm an old valve.

This pump works perfectly in our Delonghi EC702, it actually is an improvement over the original one. With these parts changed, we have a completely new machine!

Thanks eReplacement for the super fast service and clear parts catalog!

1 Removed back and L side of coffee maker, Removed coffee press capsule via port behind water reservoir. Lift top off
2 Remove 4 screws holding press capsule together, take pix so levers on bottom can be put in exactly same position. Then remove piston, the remove O-rings, clean grooves thoroughly, grease new rings, and replace them
3 Remove center phillips screw on screen on piston top, clean thoroughly w soap/water and replace
3A. Reassemble piston into press capsule, take care to insert the spring under the top level lever, and refer to your picture to reassemble to press capsule.
4. Examine tube location, remove and replace. DO not disassemble steam generator unless A. there is evidence of leakage or your unit is not producing adequate steam on steam setting.
5. Re-assemble tops side and back.

1. Removed cover with 4 screws.
2. Removed the old valve and the hose. (We needed to use a flat blade screw driver to loosen the hose.)
3. Installed the new valve and the hose.
4. Closed the cover.
5. Ready to go.

Remove the screws from outside and take of back panel
Remove screws at top of each side panel and remove sides
Remove top cover to expose the generator under the cup warming rack
Remove the retaining clips on the top tube and remove tube and o-rings
Replace tube and o-rings with new and reassemble

Disassembled replaced o ring in boiler and removed/replaced water pump
Reassemble
Works like new

Took the top off. Removed the clip. Dislodged the hose. Needle nose to pull out the old o-ring that was left in connection. Put on the new one. Put the tube back. Clipped. Done.