Reason why the lever of (commercial) lever espresso machines dont remain down

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Lincoln

#1: Post by Lincoln » Jul 09, 2019, 5:15 pm

Hi, I am regularly repairing, servicing and restoring commercial espresso machines, I come across quite a common problem with the lever machines, where a lever just doesnt sit in the down (pre-infusion) position anymore, the lever will release and want to pull up straight away without resting in its down position securely, nobody wants to work on lever which is like this, its pretty risky for safety reasons too
If somebody out there has some experience or knows the reason why, knows which part of the lever group head set up should usually be replaced then shoot I tried to do a process of elimination type trial but taking these things apart and re-assembling them aint easy, the spring is difficult to compress and perfectly align the rod through the housing to the thread on the ... bottom line it builds forearm muscles.
Lincoln

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truemagellen

#2: Post by truemagellen » Jul 09, 2019, 5:36 pm

are you saying the machine is doing this without coffee in the portafilter?

Because on most spring lever machines the down preinfusion state you must hold the lever down. There is very few machines were there is a locking mechnism on the machine for the down state which is more common in older machines or very new machines (La Marzocco Leva ie) where it is built into the handle.

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truemagellen

#3: Post by truemagellen » Jul 09, 2019, 5:37 pm

if you have a machine that you believe has the locking mechanism but it is not working like the the spring that controls it is missing or has failed

Lincoln

#4: Post by Lincoln » Jul 09, 2019, 5:50 pm

Hi, thanks for your interest, these are older machines, its not a lock as such, just once in the down position (with a loaded portafilter) it sits quite securely and can be left to preinfuse, but some clients complain because one leer will slowly stop being able to be left in the down position, without it wanting to spring up, to decompress the spring, its these old ones with the two bearings on either side with the pin through, commonly astoria and wega, the newer ones have a different housing and have two bolts that support the cam

samuellaw178
Team HB

#5: Post by samuellaw178 » Jul 09, 2019, 6:23 pm

Do you have a photo of the said group or the model of the lever? Without more detail, my first suspicion would that the rolling/moving mechanism (either the seat or the lever fork itself) has worn out. Short of replacing that there's probably not much you can do.

For diagnosis you just have to remove the group cap (if there is one) and inspect visually. Spring removal won't be required.

This is just an example of the moving mechanism on a Cimbali lever. In this design, the curvature on the fork is responsible for keeping the lever down in preinfusion position. Your customer's might be different.
Image

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dominico
Team HB

#6: Post by dominico » Jul 09, 2019, 10:14 pm

All commercial lever machines will have a mechanism to allow the lever to stay down on its own, whether a hook like the Gaggias or a cam like the Faemas, the first culprit for a failure would be mechanical wear. Do you have a source for spare parts?
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Il caffè è un piacere, se non è buono che piacere è?

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Paul_Pratt

#7: Post by Paul_Pratt » Jul 09, 2019, 10:16 pm

truemagellen wrote:are you saying the machine is doing this without coffee in the portafilter?

Because on most spring lever machines the down preinfusion state you must hold the lever down. There is very few machines were there is a locking mechnism on the machine for the down state which is more common in older machines or very new machines (La Marzocco Leva ie) where it is built into the handle.

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I do not think I have ever seen a commercial lever machine that does not have a rest position at the bottom. They all do. Some small home levers such as the Elektra do not have a rest position.

If a lever machine is not resting by itself at the bottom, i.e. the barista must hold it all the time, it must be severely worn out at the forks. A remote chance would be the spring is incorrect, broken or rusted inside, preventing the lever from going all the way down to the rest position.

Edit: The first ever Gaggia levers had no locking mechanism, the flint lock style lock was then added.
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truemagellen

#8: Post by truemagellen » Jul 09, 2019, 10:32 pm

I guess I've only worked on really old machines or ones without the lock working. There is a dual cam on one of my machines but it is protection recoil in case you release the lever with nothing in it. It does not function as a lock. Late 70s Carimali.

As for home machines to confirm My FEAR and Faema Famina (not baby of course) also have no lock/or hold mechanics cam or other type lock.

Lincoln

#9: Post by Lincoln » Jul 10, 2019, 12:23 pm

Image

These kind are the ones I come across. So im hearing its wear. Im sure one of the parts is responsible, can somebody hazzard an edcated guess and say the nuber of the part they think is the culprit?
Thanks for all input, and thanks in advance. great input

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truemagellen

#10: Post by truemagellen » Jul 10, 2019, 12:40 pm

Lincoln wrote:
These kind are the ones I come across. So im hearing its wear. Im sure one of the parts is responsible, can somebody hazzard an edcated guess and say the nuber of the part they think is the culprit?
Thanks for all input, and thanks in advance. great input
Ok so that doesn't have a spring lock. When you pull the lever the cam rocks into the bed position on item 15 which should hold it I think. So perhaps spring fatigue?