FRCN Espresso "HOW TO" Pages
by Randy Glass - All text, images, and layout are Copyright 2011 - All rights reserved
For personal, home use only. Any other use, distribution, or any method of reproduction without expressed written permission is forbidden
DISCLAIMER-As with any such procedure, do not attempt to do this unless you accept all responsibility for the procedure and its consequences. By following these instructions and reading any further you accept full responsibility.

HOW-TO 19
Overhauling and Lubricating the E-61 Group

      The E-61 group has been around for over fifty years and for good reason. It is simple to work on and it makes great espresso for a lot of reasons. But that's not why we are here. I am going to detail the steps it takes to overhaul an E-61 group.
      Be aware that there are some difference between manufacturers when it comes to this group so yours may not look exactly like this one. I am showing the manual (lever) group from the Vibiemme Domobar line. If your has an electrical activation for brewing then there will be differences which you will have to investigate before beginning. On the other hand, for the manual group, internally the general layout is the same regardless of the brand. I suggest getting a parts breakdown for your group before beginning to disassemble your machine, and compare the parts as shown on your diagram to what you read here.
      If your group may just need a quick lubrication of the cam, check out the sister article I wrote, Simple Lubrication of the E-61. If the group has been in service for a while (say, more than one year), or seen heavy use, it is a good idea to check the valve seals, and while it is apart, give everything a thorough cleaning. This article will guide you though that complete disassembly and cleaning.

PREPARATION
      The day before disassembling the group, and before shutting down, do a chemical backflush. This will help clean up some of the parts, and will also clean the exhaust portion of the brew path. You don't want to do a chemical backflush after an overhaul because it will wash away the lubricant and cause wear to internal parts of the group. Much the same can be said for a descaling. If the machine is about due for that task, schedule it ahead of time as well, although it certainly does not have to be done the night before.

TOOLS
      Most E-61 groups can be completely disassembled some simple tools:

  • One medium (10") adjustable wrench
  • One large (12") adjustable wrench
    NOTE: the large nuts and other fittings on the groups have different sizes depending on the manufacturer. For that reason I will not be discussing what size wrench you need. For example, my Craftsman 12" adjustable wrench is too small to fit the infusion housing.
  • A 5mm hex key (for groups with socket-head bolts)
  • Socket or nut driver for removal of the Gicleur (if necessary)
  • A pair of long tweezers
  • A nylon scrub pad

    PARTS
          It is a good idea to have some spare parts on hand to eliminate down time. These might include:

  • Shower Screen
  • Group gasket
  • Valve seals (3)
  • Shaft seals (2)
  • Possibly other seals for the body assembly as needed.
  • A source for replacement valves (see step 19 for details)

    OTHER

  • Descaler if scaled parts are found
  • Espresso machine Cleaner (TSP or equivalent)
  • Dow 111 or equivalent food-safe lubricant suitable for water exposure and high temperatures.
  • Two towels. One to dry and clean parts, and another one to place on the counter top to hold parts. Both should be relatively lint-free.
  • Q-tips to apply lube
  • Electrical tape (handy to put on the jaws of tools to protect chrome)
  • Paper towels to wipe lube off your hands.
  • Nitrile gloves (recommended to keep lube off your skin).
  • Flashlight
  • Eye protection

    BASIC DISASSEMBLY PREPARATION

  • Mix some espresso machine cleaner (backflush detergent) in hot water in a large measuring cup and set it off to the side. This can be used to clean parts as they are disassembled. If you have been going chemical backflushes regularly this may not be necessary.
  • Turn off machine, unplug its power cord (it's a good habit), and allow the machine to cool to room temperature.
  • If plumbed, turn off water supply!
  • Remove the drip tray cover and drip tray
  • Remove the shower screen and group gasket.
    • NAVIGATION TIP : All of the small, thumbnail images below can be clicked to view a larger image.
    UPPER GROUP DISASSEMBLY - Brew Valve
    1

    		On top of the group there will be either two large hex heads or one hex and a fitting attached by two socket-head bolts. First loosen the top hex fitting while holding the lower hex fitting if necessary.
    2 Now loosen and remove the two socket head bolts, or completely loosen the lower hex fitting.
    3 Lift the entire assembly out of the machine, dry it, and set it aside.
    4 Looking down inside of the group's bore you will see two parts: a spring and a long, narrow, brass shaft. Pull out the spring first,
    5 Then remove the brass part which it the brew valve itself. The tweezers come in handy for that. Set these aside.
    LOWER GROUP PARTS
          The lower extension of the group is made of two or three parts. If three, the part at the very bottom of the group is an extension to more accurately direct waste water into the drip tray. The Portion closest to the group is the infusion chamber which holds the infusion valve. The middle section (or lowest one depending on the group) functions in a way that you might refer to as a 3-way valve. It is called the exhaust valve.
    6 Remove The Group Extension - Loosen the group extension by holding the exhaust assembly (middle section) with an appropriate tool and unscrew the lower extension.
    Remove the extension.
    7 Remove Exhaust Housing and Valve - Hold the infusion chamber (upper section) and unscrew the exhaust assembly (middle section). Inside will be the exhaust valve, which is the shortest of the three, and the shortest spring of the three.
    Here are the parts of the Exhaust valve. Set these aside together.
    8 Remove Infusion Chamber and Valve - Now unscrew the infusion chamber (upper section of the lower-three). Inside will be the infusion valve which is the longest of the three valves, and the infusion spring which is the longest spring of these three as well. Set these aside together.
    Here are the parts of the infusion valve. Set these aside together.
    Here are all the parts which reside below the brewhead, laid out in order. Left to right they are:
  • Infusion valve
  • Infusion valve spring
  • Infusion chamber
  • Exhaust valve
  • Exhaust valve spring
  • Exhaust chamber
  • Group extension
    • REMOVAL of OPERATING LEVER ASSEMBLY
          With all three valves out of the group, all that remains is the operating cam and related parts. To remove these:
    9 Move the lever to the "middle" position. To find that, move the lever upwards towards the brew position until the first resistance is felt.
    10 Remove the nut or screw that holds the lever to the shaft. Remove the operating lever from the shaft (not shown).
    Loosen the outer nut (shown here).
    Remove the two socket head bolts (or the larger, inner hex bolt if your machine is so equipped).
    Pull the entire lever assembly straight out. You may need to slide the lever back onto the shaft and give the shaft a wiggle back and forth to get the assembly to slide out.

    Operating Lever Disassembly

    11 Unscrew the outer nut (which you loosened earlier on) and remove the spring and bushing from the shaft. The shaft can now be pulled out from the cam end.
    12 Inside the larger lever body you will find two rubber washer seals. You can see the division between them in this photo.
    13 If you have a dental pick or any similar tool which isn't too pointed or sharp, you can use it to get between the two washers and pull the outer one out first (I used the tip of these tweezers). Repeat to get the inner seal out. These are identical, by the way. Use care not to score the inner wall of the housing.
    Here are all the part of the lever assembly and the order in which they fit. Note the orientation of the brass bushing and the spring's location.
    MUSHROOM INSPECTION
    14 First thing to do is check the mushroom for scale. If scale is found here it is a good indicator that scale also exists in other parts of the system, particularly the steam boiler. A light, thin coat of scale is to be expected. Heavy deposits are in indication that a descaling is required, and you should reassess your descaling technique, chemicals used, and the frequency of descaling scheduling.
    15 Inspect the top of the mushroom. Here you will find a series of little holes. The entire volume of brewing water passes through these holes, and only these holes, when you start an extraction. It is important that these are not restricted or clogged with debris.
    16 Remove the top nut from the mushroom. Inside you will find a filter screen and the Gicleur. Look for scale bits, teflon tape, or any other foreign matter. The tweezers can be used to carefully wiggle and remove the screen. Note that one end will be formed to fit around the gicleur. Be sure it goes back in the same way.
    17 If you thought that the little holes (red arrow) that carry all the brew water were remarkable, check this out. This little brass part is the gicleur (in French, it means "jet." Anyone who has ever rebuilt a carburetor knows what that is. That little hole in top (green arrow) is what regulates all the water that brews your espresso. Yes, all the water to make an espresso has to pass through that tiny hole. Now you know the importance of that filter screen.
    18 Finally, look down inside the top of the group. There should be a seal down in there (the white part at the bottom of the bore in this photo). That is the mushroom seal (it is possible that yours came out with the mushroom. This seal is important because it makes sure that all the brew water passes through the gicleur.
    For reference, here are all the parts which reside at the top of the group and are related to the mushroom assembly: From left to right:
  • Top nut and gasket
  • Filter screen
  • Mushroom (with Gicleur installed in the top of the mushroom)
  • Brew valve spring
  • Brew valve
    • VALVE INSPECTION
        With the entire group disassembled, it is time to inspect the valves. Each valve (brew, infusion, and exhaust) has a rubber seal in the fat, round portion of the valve. Inspect the seals. Indentations are normal, but if the seal gets too worn it can leak or cause other operational problems.
    VALVE SEAL REPLACEMENT
    19     This is likely the one step in which damage may occur. The tip of the seal assembly can be unscrewed, but it has not been previously disassembled, it is likely held in place with a thread locking compound (like a type of Locktite). It is recommended that the tip be heated with a heat gun or equivalent before attempting to unscrew it.
        Hold the wide part of the valve's body. A pair of slip joint pliers and a rag to protect the valve are shown here. Unscrew the brass tip of the valve above the seal. A bit of a wiggle to begin with helps loosen it.
    20 Remove the small brass washer that is in top of the seal and you are left with the seal totally exposed. Take note of how small the threaded potion of the valve is and how fine the threads are. Work carefully! The replacement valves are not terribly expensive, but awaiting replacements will create an extended downtime.
    21

    		    The seal can be removed working a fingernail or suitable tool between the rubber seal and the brass body and lifting it just a little. After that, work your way around, lifting the seal out as you go.
        With the seal out it can be replaced. Forgot to get spares? Desperate for an espresso? While you wait for a replacement in the mail because you did not order parts ahead of time, you can flip the existing seal over and get a little more use out of it.
    22 INSPECT THE GROUP CASTING
          Use the flashlight and inspect the inside of the group. If it shows signs of coffee residue you may want to scrub it with some espresso machine cleaner. A tooth brush or bottle brush is an effective tool when used with the cleaning agent. Protect the rest of the machine by wrapping it with a towel, and insert the drip tray during this cleaning process to catch the dripping cleaner. Rinse thoroughly when done.
    BEGIN ASSEMBLY

    A few tips to get started
          All seals and gaskets should be inspected. Be sure all seating areas for these parts are clean and free of debris and are undamaged. Keep in mind that the majority of the threaded parts only have to be tight enough to keep them together and to keep them from leaking. You aren't putting lug nuts on a '63 Chevy. Over-tightening makes disassembly more difficult, increases the chance of damaging parts, can shorten the life of the gaskets, and increases the risk of leaving knuckle skin on the machine.
          Before even beginning with this, let me say that the lubricant (most use Dow 111), should be used sparingly. The little white packets which are available will be a lifetime supply for most users. Where I mention using a "thin coat," that would be enough to feel if you rubbed it with a finger but not enough to see. A "dab," is smaller than the size of one side of the head of a paper match. Yes, really.
          One way to assure yourself that all the valves point the correct way is to look into the place where they will go:

    This is a valve seat. The rubber portion of each valve will sit on a raised "edge" as seen around the circumference of the internal opening of this part.
    This is a spring seat. Notice that inside this part there is a flat surface at the bottom. The spring sits in there for support.
    Finally, no spring is oriented so that it would rest on the rubber seal of a valve.
    EXHAUST VALVE ASSEMBLY
    All the parts used in the following section of these instructions are shown in this photograph above.
    23 First assemble the exhaust valve parts and screw that into the infusion chamber. The exhaust spring is the shortest of the three valve springs, but it is the stiffest and is more easily installed with these parts in hand rather then on the machine.
    24 Drop the spring into the exhaust housing and balance the exhaust valve on top of that with the rubber sealing washer away from the spring as seen here the seals always point towards group parts and never towards its spring).
    25 Guide that assembly up into the small-diameter end of the infusion chamber.
    26 To start the threads, line the two parts up, compress them together and turn it as if you are unscrewing it. When you feel the "click" of the threads aligning, that is the time to tighten (that is a trick that works for all threaded fasteners and just about guarantees that you will not cross-thread any parts). Pushing the exhaust housing towards the infusion chamber as you turn it will help overcome the friction in the threads caused by the force of the spring. Tighten it by hand. Final tightening can be done on the group.
    27 Next, assemble the infusion valve parts by first dropping the infusion spring down into the infusion chamber. If you mixed them up, the infusion spring is the longest of the springs. Next, put the infusion valve into the spring. Once again, the rubber seal washer of the valve points away from the spring and will positioned towards you.
    28 Align this completed assembly under the group and lift it up. You may have to jiggle it around a bit to get the cam follower on the end of the infusion valve to go through the hole in the group, up into the cam's chamber. The green arrow indicates that infusion valve's end. Look into the hole left by the removal of the lever and cam assembly and you will see the tip of the infusion valve come through the hole when it when it is in place. Once there, tighten the lower assembly onto the group by hand.
    29 Use a wrench and tighten the infusion chamber to the group.
    30 While holding the infusion chamber from moving, tighten the exhaust housing onto the infusion chamber.
    31 Finally, screw the extension onto the exhaust chamber and tighten just a bit. It isn't going anywhere.
    Assembling the Components on Top of the Group
    For reference, here are all the parts related to the top of the group
    32 Make sure that the gicleur screen is properly seated around the gicleur. If the screen is sticking up it might be damaged when tightening the top bolt on the group. Install the top bolt by hand.
    33 Using the tweezers, place the brew valve into the top of the group. Look into the cam chamber and be sure that the cam follower at the end of the brew valve is properly extended through the hole (the red arrow in the photo above).
    34 Drop the brew spring (the second longest of the four) over the brew valve making sure it drops onto the recess on the valve.
    35 Lower the mushroom into the group and tighten into place. If you have socket-head bolts, tighten them until they seat, then tighten them evenly, a little at a time.
    36 Tighten the top nut
    Lever Assembly and Installation
    Here are all the parts of the lever assembly and the order in which they fit. Note the orientation of the bushing and the spring's location.
    37 Install the two shaft seals into the lever housing. Use a cotton swab with one of the cotton buds broken off as an applicator and apply a coat of silicone on the surface of the seals' bore where the lever will go through. Also lubricate the shaft portion of the of the cam's shaft with a very thin coat, rubbed well onto the surface.
    38 Slide the shaft into the housing and slide it through the seals, in the direction shown in the above photo.
    39 After examining that the seals are still in place, drop the bushing over the shaft, wide portion first.
    40 Slide the spring over the bushing.
    41 Install and hand-tighten the retaining nut.
    42 Before installing the lever assembly, use the cotton swab's stick again and place a SMALL dab of silicone on the flat end of each of the valves when they protrude into the cam's chamber (indicated by the red arrow and the green arrow).
    Also distribute a dab into the hole in the center of the far-side of the cam chamber where the end of the shaft will rest (the area indicated by the yellow arrow). You can also put a thin coat on the cam's operational surface as well
    43 Align the cam so that it is towards the front of the machine as shown here.
    44 Slide the assembly into the group. If it does not seat, do not force it, Gently wiggle it a bit and it will go in once the cam is in the correct position. Screw in the socket-head bolts (or the large hex on the housing) by hand and tighten, then tighten the outer nut. If your assembly screws into the group, put the lever onto the shaft temporarily and use it the push and turn the shaft to get the cam into place.
    45       Slide the lever handle onto the shaft, aligning the lever so that it points at about 8:30 (the "middle " position of the lever when in operation) when looking at the lever-side of the machine. Operate the lever to assure that it moves smoothly and extends to the upper and lower positions correctly. Install and tighten the screw or nut that holds the lever in place on the shaft.
    46 Replace the shower head, shower screen, and group gasket if removed earlier. Replace the drip tray.
    47 Turn the water back on if necessary, then plug the machine back in. Turn the machine on and lift the brew lever to the brew position and flush some water through. Insert a blind filter in a portafilter and do a few clear-water backflushes to check for leaks.
    48 If everything looks good, allow the machine to come to operating temperature and do a few more blind backflushes to help clean out any stray lubricant.
    Time To Make Some Espresso!
    Coffee Cup
    Home