Espresso machines are NOT zero maintenance devices. Failure to maintain results in foul tasting espresso and mechanical problems. This is the full service routine that I have developed during the past five and half years for my 1999 real brass La Pavoni Europiccola and my rather antique 1978 one. This is more comprehensive than merely cleaning and re lubricating seals. The key to keeping lever espresso machines in good condition is periodically doing complete inspection and maintenance. I suggest such a service is needed at least once a year. I realised from the required force to move the handle that it was time for this today for the 1999 La Pavoni Europiccola. Here is my "full inspection" and service routine which performed about an hour ago:
1. Place a white dinner plate or large soup bowl on the work table to be used. Get the following tools and put on the same table: 2 10mm open end, 2 14mm open end, screw driver to fit screw or screws holding base plate. (If one have original lever pins, circlip pliers.)
2. Place the La Pavoni on the work table and remove the screw holding the plastic sub base. Remove the plastic base and inspect inside. (Note that some earlier models have metal sub bases.) Inspect everything inside the base, check for leaks and corrosion. With steel bases, remove any rust, cover are with anti rust paint. When satisfied that all is well, replace plastic base and screw.
3. Remove boiler cap and look inside using a light. The water should be clear and there should be little or no scale on the boiler walls. Act on any problems! Replace boiler cap.
4. Remove the two lever pins. Place them on the white dinner plate. Remove the handle. Put the roller through which one of the lever pins went onto the dinner plate. Remove the acorn nut and flat nut at the top of the piston rod. Place on dinner plate.
5. Push the piston rod downward to remove the piston, dispersion screen, and portafilter sealing O ring. Put a towel under group to prevent piston falling against the base. If the machine were serviced frequently it should be easy to remove. Clean the piston, dispersion screen, and O ring thoroughly. They tend to be covered with black tarry matter. I wash with dish soap and then rinse thoroughly, others use other things. Place these three cleaned items on the plate.
6. Remove the two bolts holding the group to the boiler. (This is a "full service".) Clean the group very thoroughly, I like to polish the bore inside with things like Brasso. Clean the grooves on the bottom where the portafilter attaches. (I have a small stainless steel brush that I use for this.) Be sure to rinse the group with clean tap water, then dry it.
7. Check the group bolts to be sure they are not damaged and reattach the group to the boiler. It is a good idea to lubricate the O ring with silicone grease. If one have good bolts there will be a sudden point where the torque required to turn the bolt increases suddenly. Stop turning just beyond that point. Do not over tighten! Tighten bolts sequentially, a bit on one side then the other.
8. Lubricate the piston seals with silicone grease, do not use a large excess. Lubricate the piston rod with the same grease. Carefully push the piston up into the group, keeping the hole for the lever pins aligned correctly. Be careful as the upper seal enters the bore to be sure it enters properly. Push the Piston all the way up.
9. Using heavy grease, not silicone, lubricate the lever pins and roller. I use a tooth pick to apply. Put the roller in place, put the lever in place and install the two lever pins. (This is much easier if one discard the stock pins and replace them with 6mm brass or bearing bronze rods threaded on the ends.)
10. Put the portafilter O ring gasket over the dispersion screen and push into place. Put the portafilter with an empty basket on it in place and use it to push the dispersion screen and ring into the bottom of the group. Leave them in place, and screw the thin nut that fits on top of the piston rod all the way down until it JUST contacts the stop. Hold it in that position with one of the 14mm tools, and then bring the 14mm "acorn" nut down against it, and tighten it against the thin nut. Be careful NOT to turn the thin nut while doing this.
11. Check all external fittings. It is a good idea to turn all nuts just a bit to be sure that they are not seizing at each servicing, especially the ones on the sight glass. Be sure to check that the threaded rod holding the handle to the portafilter is not corroding.
12. Put the machine in its usual location. Fill it with proper water. Power it up. If you do not have a permanently attached pressure gauge, attach it to the machine. If pressurestat equipped, check the pressure where the heater turns off. With the two switch model, determine where the pressure relief valve releases pressure.
13. Adjust the nut on the steam valve while under pressure so that there is only very slight resistance on turning the nut farther. If everything be in good shape, it should not need to be tightened down more than that.
14. Grind some good espresso beans, and press them into the filter basket. Bleed the machine as required. Enjoy the espresso. Its flavour is why one does all of this!