Ponte Vecchio Export problems - Page 3

A haven dedicated to manual espresso machine aficionados.
User avatar
Eastsideloco
Posts: 1657
Joined: 13 years ago

#21: Post by Eastsideloco »

wintoid wrote:After trashing a second set of seals, my friend has made me this device...
That's a good friend. Looks like just the tool for the task.

No doubt the manufacturer has a custom tool like this.

User avatar
peacecup
Posts: 3649
Joined: 19 years ago

#22: Post by peacecup »

Enjoy the 'spro!

PC
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#23: Post by wintoid (original poster) »

Eastsideloco wrote:That's a good friend. Looks like just the tool for the task.
Yes, really. I was on the verge of selling the machine and going for the MCAL instead (which looks like it's a bit easier to get to the piston). Picking my machine up tomorrow and looking forward to trying it out again.

:twisted: :twisted: :twisted:
Simon
LMWDP #486

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#24: Post by wintoid (original poster) »

Woohoo changed my piston with no problems, and my leaking issue has gone since the seals were changed. Brilliant!
Simon
LMWDP #486

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#25: Post by wintoid (original poster) »

I've had this before but never understood it... what does it mean when the piston slips just after you take the pressure off the lever? What should I do?
Simon
LMWDP #486

User avatar
peacecup
Posts: 3649
Joined: 19 years ago

#26: Post by peacecup »

It means that there is little pressure between the bottom seal and the coffee puck. This could be due to a few causes:

1. Low boiler pressure, resulting in low pressure in the group when the lever is pulled down. It is boiler pressure that forces water into the group when the little port is opened. This happens when the lever is pulled down. If you have not released false pressure, or if you operate the group before the boiler is up to pressure, the lever can jump upon release.

2. A bad or misplaced/dry bottom seal: Possibly when you changed the seals the bottom one was slightly damaged. Or it could just be dry, and will seal better when it is in constant use.

3. The puck is not creating enough pressure- grind too coarse, portafilter not locked in all the way, portafilter gasket damaged, etc. Anything that would let pressure bypass the puck too quickly will allow the lever to jump.

I've noticed this on occasion - if you notice it directly you can simply pull the lever down again immediately. The next time it will usually catch as normal. This would indicate number 2 above was the reason. Let's hope it is a dry, and not damaged seal, and that it will dissapear soon.
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#27: Post by wintoid (original poster) »

Thanks Jack, again I am in your debt, you're always helping me!

You're right, if I pull the lever down again immediately, it catches fine.

I also tried one other thing. Normally I pull the lever down until just before the water comes out, and then I fit the portafilter. This time I tried pulling the lever until water came out, then backed off, then fitted the portafilter, and that caught straight away (might be a fluke).

I've temporarily moved back to the Caravel whilst I decide what to do next :D Nice to have that option.

Would it be worth me lubing the inside of the piston chamber with Molykote do you think, on the basis that perhaps the bottom piston seal is dry? Alternatively, the one seal I didn't change was the one on the main gasket, which looks pretty easy to change. I could do that.
Simon
LMWDP #486

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#28: Post by wintoid (original poster) »

Sorry Jack, one more thing... assuming your suggestion (2) is correct, does this mean that hot water (and coffee) has made it past the piston, and into the cavity behind the piston where the spring is?

Thanks...

Simon
Simon
LMWDP #486

wintoid (original poster)
Posts: 86
Joined: 12 years ago

#29: Post by wintoid (original poster) »

I took the piston out again and lubed it quite a lot with Molykote 111. Piston back in, and no slippage. Yay!
Simon
LMWDP #486

User avatar
peacecup
Posts: 3649
Joined: 19 years ago

#30: Post by peacecup »

Great - glad to hear it's back in action. Lets hope that cures it for good. My AM cappa on the Lusso was mouth-watering today...

PC
LMWDP #049
Hand-ground, hand-pulled: "hands down.."

Post Reply