Bent piston -- can it be fixed?

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beer&mathematics

#1: Post by beer&mathematics »

Sad news for my old Sama Export piston...

today, I tried to do some routine maintenance by taking out the piston and adding silicone grease to the seals (which are only a year old) and I messed up putting the piston back in.




I do have the PV piston removal tool to aid me, but somehow I didn't notice that the upside down v seal got jammed as I tried to force the piston with the tool. This made the piston stuck and I had to hammer it out with a rubber mallet. Here's the damage :cry:



I did a quick search and don't see any of the Ponte Vecchio distributors selling a piston, so my question is can this be saved?
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IamOiman
Team HB

#2: Post by IamOiman »

Ouch! I've never seen a piston damaged like that before! However if you are unable to save it a new one can be purchased at lamacchinadelcaffe (scroll down a bit to find it)

https://www.lamacchinadelcaffe.com/rica ... cchio.html#
-Ryan
Using a spice grinder violates the Geneva Convention
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beer&mathematics (original poster)

#3: Post by beer&mathematics (original poster) »

Thanks Ryan, I checked them first and somehow in my sadness I totally missed it! I dunno if I can fix it, but I will replace the seals and see if it works with the bent piston. I will probably just order the new one tho.

Is there an espresso equivalent of the opposite of "green thumb" :?: Well, it'd be me...
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LuckyMark

#4: Post by LuckyMark »

I would just wait for the new piston. Hard to tell how out of round it is from the photo but there is a chance you could score the bore and wreck it too.

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beer&mathematics (original poster)

#5: Post by beer&mathematics (original poster) replying to LuckyMark »

New piston it is. This is what it was like after removing the seals:


Thankfully I can buy a replacement (and just placed the order) but it does sadden me that a little less of the original machine is left.
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IamOiman
Team HB

#6: Post by IamOiman »

As sad as it is, it is very fortunate the part is still available new!

That piston definitely sheared a bit! Lamacchinadelcaffe is super quick, they shipped my order yesterday from Italy for my Bezzera Family and it should be here tomorrow! They used DHL in the past but this time it is UPS
-Ryan
Using a spice grinder violates the Geneva Convention
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truemagellen

#7: Post by truemagellen »

So did u end up damaging the cylinder? Sorry I didn't fully understand how it happened. If so please hone it.

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beer&mathematics (original poster)

#8: Post by beer&mathematics (original poster) »

Ryan, after the initial tears I am indeed very happy to have a new piston available :wink: Also, LaMacchinaDelCaffe is awesome! Used them last year to get a bunch of parts when I rebuilt my Export (remember it was in a box in pieces when I moved from NYC to CA). What I really like about them is that you pay 25 euro for shipping but they will refund you a certain amount after they process your order. This time I got a 18 euro refund so shipping was only 7 euros-crazy!

About the cylinder, it does look a little wonky by eye but not too bad. I'll just have to wait and see if it works after the new piston arrives.
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XS750AU

#9: Post by XS750AU »

Run your finger over the cylinder. If you can feel a burr then it will destroy your seals.
The best way to fix it is to use a cheap cylinder hone in a drill. Wet and dry abrasive sheet can also work but you risk making a groove in the cylinder.


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beer&mathematics (original poster)

#10: Post by beer&mathematics (original poster) »

Thanks Jason and Tim-I learned a new technique "hone a cylinder". Will read up on this a bit before I try it and thanks Tim for the image so I know what to look for.
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