Hey Folks
Trying to diagnose this before the inevitable dismantling. Dismantling is a real pain in the @$$ as it's plumbed in and my bench is narrow. Very limited working space...will need to move the microwave...

So....
The lever has been sticking only on the return (down) path. The stroke up is lovely. The stroke down is nasty.

I suppose this is one of the pistons?

Any advice what to look for?

The most likely cause is friction between the external cam on the brew lever and the brew switch.
Next is the seals on the lever's shaft and the interface between the lever's internal cam and the brew/infusion valve.
For more detail on the E-61 group, see these two articles on my website:
How-To 18 - Simple Lubrication of the E-61 Group
How-To 19 - Overhauling and Lubricating the E-61 Group
The only thing to watch out for is not confusing the two longer springs in the group. Also be sure each spring and valve is fully seated when assembling.

EDIT: Disassembling the group on the Vibiemme is actually quite easy. It does take a large wrench to get the infusion chamber off. A smooth-jaw pipe wrench will do it. You can put electrical tape on the jaws to protect the chrome. A strap wrench might even do it. The rest is quite straight forward.

Time to visit RandyG's page. #18 in the How To section will be of importance to you. #19 covers a full rebuild, so hopefully you are not there yet.

Randy G. wrote:The most likely cause is friction between the external cam on the brew lever and the brew switch.
Next is the seals on the lever's shaft and the interface between the lever's internal cam and the brew/infusion valve.
For more detail on the E-61 group, see these two articles on my website:
How-To 18 - Simple Lubrication of the E-61 Group
How-To 19 - Overhauling and Lubricating the E-61 Group
The only thing to watch out for is not confusing the two longer springs in the group. Also be sure each spring and valve is fully seated when assembling.

EDIT: Disassembling the group on the Vibiemme is actually quite easy. It does take a large wrench to get the infusion chamber off. A smooth-jaw pipe wrench will do it. You can put electrical tape on the jaws to protect the chrome. A strap wrench might even do it. The rest is quite straight forward.

Awesome resource Randy.
Cheers!

Hi Randy
I took some pics. Looks like the cam has some wear. Is this normal after 3-4 years?
Silly question - does it need to be replaced?
I guess this scouring explains the rough return...



The lower piston looks to be in good shape with minimal wear.

I lubricated with some olive oil (no food grade silicone on hand)

That is very excessive wear. I would guess that this machine is backflushed with detergent far too often. Mine has been in daily use for 4 years and the chrome on the cam is barely worn at all. I would replace that cam immediately. Remove and examine the ends of the brew and infusion valves. the edges should be slightly rounded. If they show signs of wear, replace those as well. Might as well see if all the tips of the valves can be unscrewed. If yes, order new valve seals. If no, replace the valves. Also get replacement seals for the cam lever (there are two in there). Also get some Dow silicone grease with the order. One little envelope will last years. Put a tiny coat of it on the valve's threads as well so they come apart easier next time when the seals need replacing.

I do not know your use of the machine nor cleaning regime, but if someone just showed me those images I would say, stop using detergent to backflush. There is no need to do that. If the group needs cleaning, disassemble it, clean the group casting and all parts with a proper cleaning agent, and lube all friction points during assembly.

When I order I get a two sets of valve seals so I can replace them all and have a spare set on hand. I seal them in a vacuum bag to keep them fresh. If you don't have that, coat them with a little talcum powder and squeeze the air out of a zip lock bag.

Randy G. wrote:That is very excessive wear. I would guess that this machine is backflushed with detergent far too often.

Randy G. wrote: I do not know your use of the machine nor cleaning regime, but if someone just showed me those images I would say, stop using detergent to backflush. There is no need to do that. If the group needs cleaning, disassemble it, clean the group casting and all parts with a proper cleaning agent, and lube all friction points during assembly.

Thanks Randy. I'll source replacements.
I perform a detergent backflush literally once a year, but I do water backflush after each use (1-2 shots).
Is this ok? (I kinda thought you could water flush to your heart's content...)

I have had issues with the lever in the past however.
When it was under warrantee, the shop replaced the cam after I complained of stiffness. This didn't really improve the situation so eventually they replaced the valve pistons.
Its been good for a couple of years so I guess the water backflush is stripping the natural oil lubricant

Hi Randy
Another silly question.

Your page shows orientation of the cam to the front of the machine

But the group head diagram shows it to the back

Does it matter?

If they are using genuine VBM parts I cannot tell you why the cam looks like that. I do a plain water backflush (blind filter extraction - no coffee) after every time I use the machine before shutting it off. Maybe when the shop replaced the cam the first time but did not replace the valves, the old valves wore the new cam a little, and then when the valves were replaced the wear on the replacement cam had already started...? Maybe the water you have is also a part of the problem. Bad PH or something. Maybe the 3-way spring (which is the strongest of the three) is not properly seated and putting too much force on the cam when lowering the lever...?

The cam will only go back in one way and still work. If put in wrong then it will not rotate fully because of part #23 (the stop screw), so that is an easy one to figure out. Watch the video: