Lelit Mara X: Adjusting The Pump Pressure at the Expansion Valve

On vibratory pump equipped machines, like the Mara X, the pressure at the group head is regulated by the expansion valve. Follow these instructions to adjust the set pressure on your machine.

Tools Needed:

Portafilter with back flush disc installed
Phillips head screwdriver
12mm crescent wrench
Pliers/tweezers (if removing the gasket seat for service)

1. Remove the top panel from your machine and locate the expansion valve.



2. Lock your portafilter (with the backflush disk) into the group head and lift the brew lever. 

3. Watch the pump gauge rise, and see what it settles at, if it is over 9 bars, you will need to loosen the valve by turning counterclockwise, and if it is lower than 9 bars, you will need to tighten this part by turning clockwise until it reaches the desires pressure. 
(Do not allow the pump to run for longer than 35 seconds at a time while setting your expansion valve)

- Please use caution when using the wrench to adjust the valve while the machine is hot and receiving live voltage - 





4. If you need to fully remove the top portion of the expansion valve for service, you will want to turn the machine off, and unplug it before reaching it to pull off the silicon tubing. 



5. You can use the same size 12mm crescent wrench to unscrew it by turning counterclockwise until the spring pops the top off. 



6. Use the pliers/tweezers to remove the spring and gasket seat from inside of the valve for inspection (the one pictured below should be cleaned up a but with a scouring pad or sand paper on the metal, and add some food safe lubricant before reassembling to test).