Still restoring this older VFA Expres and have finally manage to disasemble most of the group head. All of my research, the group head tear downs have 2-3 cams. One in the mushroom and one in the pressure drain release below.

This machine I'm working on has neither. I'm not able to remove the solenoid yet for the lower drain, I was able to remove the bottom spout. There is a spring in there, but no cam.

Prior to tear down, the buttons did operate normally. No leaking at all.

Is it only lever machines that have cams, or maybe some machines don't need them?

A photo would help, but there's E61 espresso machines with just a solenoid instead of the preinfusion chamber (e.g., La Valentina, Wega Mininova). Is that what you mean?

I think there is a nomenclature problem. Manual E-61 machines have three valves (brew, infusion, and 'drain' or 'exhaust' if you want to call it that which acts as the 3-way) and just one cam operated by the manual lever on the side of the group. The E-61 groups with a solenoid operate very differently. I can only guess as I have never had one (nor would I), but there is no cam and I do not know if there there is an infusion function built in.

What I thought was an unremovable piece was threaded lightly (thankfully).

Quite different from the replacement mushroom I just purchased as recommended. I think it may be time to find another shop/'technician' group.

Thanks for anyone's help for finding a replacement!

FYI Images are posted, but in Chrome I'm not seeing them.

humantopus wrote:FYI Images are posted, but in Chrome I'm not seeing them.

Do you have an ad blocker installed? I've heard from another member (JohnB.) that it is preventing HB from showing post images on Chrome.

Gotcha. That was it. Whitelisted!

humantopus wrote:Still restoring this older VFA Expres and have finally manage to disasemble most of the group head. All of my research, the group head tear downs have 2-3 cams. One in the mushroom and one in the pressure drain release below.

It's the same cam inside the head. In the E61 heads with a control lever, raising the lever moves the cam upward and it opens the brew valve. Lowering the cam moves it down where it pushes the pre-infusion valve open (And that valve's extension pushes the drain valve open).

In an E61 without a control lever (Automatics that dose out the water) there is a solenoid valve that replaces this movement.

The back end of the control lever is also in a cam so that when raised that end presses the pump button on the face of the machine.

Does that explain it? And/or have you solved your issue?

Absolutely an excellent explanation! Thanks for letting me know. Will definitely be looking for a lever group in the future. Love the analog feel it must have.

Although no, unfortunately it doesn't solve my issue as the new mushroom isn't threaded. I'll have to return it look for a replacement, or match the thread and tap. Hopefully the loss of chrome after tap won't compromise the structure.

Any suggestions for part number or item stock?

Edit: Ignore this first paragraph, I wasn't looking carefully at the photo of the new mushroom.

Sorry, can you post a photo of what you're trying to do?
Are you talking about the "Bell section" of the mushroom and how it threads on to the top section, basically the larger hex-nut section? Or just how the gicleur (Little brass precision sized jet/hole) threads into the larger hex-nut section below the mesh and smaller hex-nut section of the head?

EDIT:

Wait a minute, I get it. I revisited your photos.

You're saying that your old Gicleur won't thread into your new mushroom...
Can you contact the retailer of your new mushroom with photos of the old one?

And my final question, do you need to replace the mushroom? It doesn't look damaged to me. Am I missing something?

Correct the old Gicleur can not be placed into the new mushroom, as there are no threads. I can tap new threads into it no sweat, but won't bother if I can find an appropriate replacement.

The o-ring that I removed from this old mushroom is too small. The size to place it was fine, but the rubber tickness was too thin to fill the entire placement gap. Will order a thicker one online after I take the precision callipers to it.

The old mushroom is chrome-pitted and corroded enough to warrant replacement... or not? I've put it into cafizza (Puro here in Canada?), scrubbed and removed most of the surface mess with a plastic brush. Haven't put it into a descale solution yet though.