La Marzocco GS3 Maintenance, Issues, and Upgrades - Page 2

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
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Jake_G
Team HB

#11: Post by Jake_G »

Looking great!

Make sure you bleed the coffee boiler through the group cap and get all the air out before playing with the valve. It is very non-linear and "spongy" when you've got any air in the system at all.

Cheers!

- Jake
LMWDP #704

Milligan (original poster)

#12: Post by Milligan (original poster) »

Thanks for the tip. I'll be sure to do that once I get it all back together.

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Jake_G
Team HB

#13: Post by Jake_G »

Also bear in mind that the clippard valve shaft has #5-40 threads through a soft brass bonnet. Trying to close the valve with force, even with a 50mm plastic wheel (I used a copy of the temperature wheel on the tea water mixing valve), results in those soft brass threads pulling right out of the bonnet.

Cheers!

- Jake
LMWDP #704

Milligan (original poster)

#14: Post by Milligan (original poster) »

With that in mind, I'll likely add a positive stop to the knob so it never bottoms out. I can't see a situation where I would want to completely close the valve anyway.

Milligan (original poster)

#15: Post by Milligan (original poster) »

Something I learned about going through a used espresso machine... if you crack a seal then good luck sealing it again! :D

I ended up having to replace the copper crush washer on the group head bleed bolt. The crush washer on the vac breaker needed what seemed like excessive torque to seal even after fine sanding the mating surfaces. The teflon tube going into the steam wand needed to be cut back to seal again. Finally, don't get me started on sealing the compression fittings. The weird and tight angles made getting the ferral to align properly quite a chore. I need children's hands to work on it. The OPV didn't give me any fuss though.

It is back in business. The milk frothing was my main concern and it is much better now. Swapping the tip out for the L178 made a huge difference. I can finally get texture to my milk. The first one I did actually came out more like a cappuccino so I don't have to stretch nearly as much as I used to.

I'm getting used to the Jake valve. I keep having to remind myself it is flow control, not pressure control. I feel like it opens up a ton of possibilities but want to make sure I don't use it as a crutch for a poor dial in. I can easily extend the time to hit 2:1 @ 30s on the dot by working the valve to control the flow rate but that does not mean it will be a good cup. I have to rethink my dial in from the ground up with this new control in mind. Not quite sure what to make of it yet. I'm thinking I'll set my machine to 6bar at the bypass to set a baseline and play with it from there.

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Jake_G
Team HB

#16: Post by Jake_G »

How's it going after spending a few weeks getting to know the new valve?
Milligan wrote:I'm getting used to the Jake valve.
LMWDP #704

Milligan (original poster)

#17: Post by Milligan (original poster) replying to Jake_G »

Thanks for checking in. I haven't spent a lot of time experimenting yet. I've been doing traditional shots lately because we've had a lot of friends and family come through the past few weeks (probably went through 3-4 gallons of milk making lattes/caps.) I also had an Amazon BSPP to NPT fitting give me trouble. The included oring leaks once a week. I think I'll have it repaired and then it will start again out of no where. I'm swapping to a crush washer now.

Hopefully I'll have a better chance once I get some light roasts finished and the fitting sorted.

Honestly, if I had to do it again I would have just ordered your parts and be done with it. It seems a lot of the "hardware store" quality small compression and adapter fittings are hit or miss at pressures higher than a water main.