La Marzocco GS3 problem with portafilter fit?

#1: Post by **stuart1927** » June 11th, 2014, 8:00 pm

I've had my gs3 for just over 6 months now and it's a great machine.

I have one problem however. I've always noticed that the portafilter is quite difficult to engage properly and I often have a minor leak during extraction. Part of the problem is it almost feels like a metal to metal seat....the gasket doesn't seem to offer any seating surface or compression.

Is this a common issue or do I just have a defective gasket?

I was previously looking at an E61 group machine and the portafilter seemed to lock in very securely v's the GS3!

Many thanks

sbb

#2: Post by **Marshall** » June 11th, 2014, 8:04 pm

You should have replaced your gasket 3 months ago. They're cheap. Buy a bunch and calendar a replacement schedule.

June 11th, 2014, 8:25 pm

Wow....I would have thought 6 months at least....my machine only gets moderate use. But is seems probable having looked just now.

Many thanks

sbb

#4: Post by **Marshall** » June 11th, 2014, 8:41 pm

It's not use. It's the constant heat baking the rubber.

#5: Post by **caffeinezombie** » June 11th, 2014, 9:42 pm

You may want to give the cafelat silicon gasket a try, they have one designed for LM groupheads. I have using mine for a month or so and it works beautifully.

#6: Post by **rbh1515** » June 11th, 2014, 10:25 pm

Marshall wrote:You should have replaced your gasket 3 months ago. They're cheap. Buy a bunch and calendar a replacement schedule.

What??? I have had my GS3 for about 6 years. I change the gasket out every 9-12 month, and usually they are still fairly pliable. I have never had any leaks. Changing out the gaskets every 3 months is a waste of your time and money.
Rob

#7: Post by **uscfroadie** » June 11th, 2014, 10:53 pm

I think Marshall runs his 24/7 which helps attribute to a shorter life.

Stuart - is your gasket clean? If yours is leaking, you might have some grounds pressed into the rubber. Pretty easy to remove, clean , and re-seat.

Although I have a few extras of the stock LM gasket, I will definitely give the silicone Cafelat gaskets a shot. My Breville DB has a silicone gasket, and after 1.5 years and over 3,000 shots it's still as pliable as it was when brand new, though it's a little stained from the coffee.

#8: Post by **shawndo** » June 11th, 2014, 11:55 pm

Yeah, keep a supply around and change it when it leaks a little. When you take it out, you can feel the difference between it and a new one.

I have an extra Cafelat silicone LM gasket if you want one. Just PM me your address.

Also, just 'cause it took me a while to find the best tool, get one of these hook/pick sets

http://www.amazon.com/Stanley-82-115-Pi ... =pick+hook

The dental pick I first tried to use didn't cut it.

#9: Post by **Peppersass** » June 12th, 2014, 2:08 am

What size gasket are you using?

There are two stock gasket sizes: 6mm and 8mm. The 6mm size should be used on newer machines that don't have much wear on the portafilter ears and grooves in the group. The 8mm size should be used on machines that have worn portafilter ears and/or grooves.

When I install a new stock gasket, I can feel some give (softness) in the gasket when I lock the portafilter. Between sessions I leave the portafilter loosely in the group, and often when the gasket is new the basket will slightly adhere to it. If the basket is ridgeless, it'll come out of the portafilter when I remove it from the group.

After the gasket has been in use for a few months, it gets hard and and I can no longer feel any give when I lock in the portafilter. The basket no longer adheres to the basket between sessions. The gasket is still usable for several months after that, but when I start having to lock the portafilter down with some force to avoid leaks, I know it's time to change the gasket.

I have some silicone gaskets coming. Hopefully they won't dry out like the rubber gaskets.

FWIW, I use the timer to shut off the machine from 8 pm to 6 am.

#10: Post by **shadowfax** » June 12th, 2014, 12:56 pm

Great advice from Dick. One thing:

Peppersass wrote:There are two stock gasket sizes: 6mm and 8mm. The 6mm size should be used on newer machines that don't have much wear on the portafilter ears and grooves in the group. The 8mm size should be used on machines that have worn portafilter ears and/or grooves.

I think the Conical 6/8mm gasket is the best for a new/home use LM (or compatible group). The conical shape makes the gasket compress inwards against the sides of the group when locked down (rather than simply upwards for a flat gasket), reducing the amount of gunk that migrates into the area behind the gasket over its life, which helps keep that hard-to-clean area cleaner. I wish Paul Pratt would do the silicone gaskets in that shape.