Spring Lever Piston Seal Life

#1: Post by **AMac** » October 12th, 2019, 10:58 pm

How long do you go before piston seal replacement? I have the cafelat silicone seals in my Pro 800, and it's been about 2 years since I've replaced them.

I'm not sure if it's related to the piston seals, but I have a slow drip coming through the screen, probably 15mLs over a 12 hour period. Could the old seals be the issue? I pulled the piston to grease the seals and the bottom seal was brown, the middle seal was brownish red and the top seal was red.

#2: Post by **DanoM** » October 12th, 2019, 11:57 pm

On my Bezzera Strega I had standard seals that lasted about 5 years. Liberal Dow 111 helped in the last couple of years to keep the leaks to a minimum. Intermittent cleaning of the seals when pulling the piston once a year probably helped extend their life. About 4 shots a day for my machine. (11 months offline due to a move, so 4 years of actual use.)

Recently replaced those seals with the Cafelat silicone seals as one of the old ones had some grooves, and grease wasn't helping stop a leak.
The Strega is an HX, so when the pump isn't activated there's limited leak capability compared to your Pro 800's dipper configuration. A groove on a seal in my Strega wouldn't be nearly as annoying as it would be on a dipper group with constant water pressure.

Get a spare set of seals on standby and clean the grime off your seals with some espresso cleaner to see if that helps. Look for any chips or grooves in your seals and replace damaged ones.

#3: Post by **bettysnephew** » October 13th, 2019, 9:25 am

I have a Bosco with its' original silicon seals still in service after 2+ years. Mine will exhibit extended shot timing when the seals need a relube (about yearly). Pull apart and clean/lube, so far, so good. I suspect your Cafelat seals may have similar lifespan. If the drip continued after relube I would replace the seals.

#4: Post by **samuellaw178** » October 13th, 2019, 3:57 pm

The last set of standard rubber piston seals on my Brugnetti Aurora lasted about 3 years. I've changed them recently. There's no leak or lever slipping, but did become hardened with age. With silicone ones, I suspect they would last much longer.

#5: Post by **espressotime** » October 14th, 2019, 3:05 am

Only one seal on my Pompei piston .Almost 7 years since I replaced it.Still flexible and going strong.

#6: Post by **truemagellen** » October 14th, 2019, 4:09 am

DanoM wrote: The Strega is an HX, so when the pump isn't activated there's limited leak capability compared to your Pro 800's dipper configuration. A groove on a seal in my Strega wouldn't be nearly as annoying as it would be on a dipper group with constant water pressure.
.

The LSM group has a separation preinfusion valve from the piston that is activated with a mechanism on the back of the lever. Izzo Levas are dippers with the LSM group.

And here is Pro 800. If pro 800 were a Thermosyphon it could also experience a leak when the seals are failing,.

October 14th, 2019, 4:13 am

You can adjust the preinfusion timing when the valve opens with the bolt at the valve. That way you can make lower pressure shots.