La Marzocco GS3 vacuum breaker cleaning?

Need help with equipment usage or want to share your latest discovery?
CelliniEVO

#1: Post by CelliniEVO »

Hey guys,
I've recently noticed constant steam coming out of the drip tray on the right side of the machine (under the side with the hot water dispenser) I've done some reading and it sounds like the vacuum breaker is most likely stuck open.
I'm wondering if there's a video or a detailed post documenting how to clean it? All I've came across so far is someone who was updating his vacuum breaker: Updating the La Marzocco GS/3 vacuum breaker
I'm assuming since mine is draining into the drip tray I have the updated design? It has a 1900 serial number and a manufacture date of 01/12.

I'm yet to open the machine, so before I do for the 1st time I want to have a real good idea what exactly I'm doing....if my wife can't have her 2 morning lattes, I'm gonna be dealing with some bitchin.

Thanks guys

DaveC

#2: Post by DaveC »

CelliniEVO wrote:Hey guys,
I've recently noticed constant steam coming out of the drip tray on the right side of the machine (under the side with the hot water dispenser) I've done some reading and it sounds like the vacuum breaker is most likely stuck open.
I'm wondering if there's a video or a detailed post documenting how to clean it?
Thanks guys
It's probably better to simply replace it, they are only a few dollars. With a machine of that value, it would be worth doing. I also think the steam boiler is on all the time (can't be switched off)? If so even more reason to just replace.

CelliniEVO (original poster)

#3: Post by CelliniEVO (original poster) »

It appears I have the updated vacuum breaker as there is clear hose attached to the top to feed off the condensation.
How do I safely go about removing it? Do I remove the hose and just loosen the connector above that brass washer in the photo?
I've read of people soaking in vinegar and salt....does the ratio or dilution matter?

Thanks guys!


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Peppersass
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#4: Post by Peppersass »

Before you attempt to clean the vacuum breaker, contact your dealer or La Marzocco USA and purchase one or more vacuum breaker rebuild kits. The kit consists of a replacement valve stem, a replacement teflon bushing and a replacement O-ring. It only costs a few dollars. Here's what you get:



While you may be able to disassemble your valve and clean the parts, this won't do you any good if the O-ring is worn out. Depending on how long it's been in service, you may be able to get away with cleaning the O-ring for a while, but eventually it will disintegrate. So at the very least you should get some replacement O-rings. It's less likely that the valve stem or bushing will be worn out, and you can usually clean any gunk off of them, but just in case it's good to have a full rebuild kit on hand.

Of course, before removing the valve you must turn off the machine, unplug it and let it cool completely.

You can pull the clear hose off the nipple of the valve. In theory, you can unscrew the valve just above the brass washer, as you suggest, but the fitting is screwed on tight and it's tough to get a 17mm wrench in there. I always disconnect the elbow fitting at the boiler and remove the entire assembly (also 17mm, but you may have to use a 19mm wrench to hold the plated adapter to keep it from turning too.) Either way, if you can't get your wrench or wrenches into the space, just remove the rear cover. It's held in place by two phillips screws at the lower corners. Take them out and pull the rear cover straight up. Be careful not to pull the brain box out after removing the rear cover.

I use a vice to hold the valve/elbow assembly to get it apart, but you may be able to do it with two 17mm wrenches. Once you remove the valve from the elbow, you must remove the brass adapter from the valve body in order to get the valve parts out (you can't do that by removing the fitting at the top of the valve, so don't try.) Once disassembled, the valve assembly looks like this:



Here's how the stem, bushing and O-ring go together:



Put it all back together by following the above steps in reverse order.

In addition to buying one or more rebuild kits, you can buy a replacement valve assembly. That way, you can swap in a new/clean one and take your time cleaning or rebuilding the old one. I believe the valve itself goes for about $30. I bought a spare elbow, too, so I could do a very quick swap, but that may be overkill for most people. I believe the cost of the entire assembly was around $60.

As for cleaning, I've always used distilled vinegar. Don't know about using salt.

Oh, and I'm the guy who posted the thread on upgrading the vacuum breaker on older GS/3s. :D

CelliniEVO (original poster)

#5: Post by CelliniEVO (original poster) »

Thanks for the photos and in depth explanation! I really appreciate it and it's a great idea to order a spare before I attempt the cleaning. I'm going to contact LM shortly and get one on order. I'll keep you posted on how it goes.


Thanks again!

CelliniEVO (original poster)

#6: Post by CelliniEVO (original poster) »

Just contacted LM USA and was told I can only buy the whole valve assembly for 32 bucks? Were you able to just order the o-ring, bushing, and valve stem?

Thanks

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erics
Supporter ★

#7: Post by erics »

Unfortunately, it seems, as you wrote, that rebuild kits are no longer available. If you wanted to become a vacuum breaker o-ring distributor, see this:

O-rings & Copper Sealing Washers

For sure I agree with Dick's, as usual, excellent writings.
Skål,

Eric S.
http://users.rcn.com/erics/
E-mail: erics at rcn dot com

CelliniEVO (original poster)

#8: Post by CelliniEVO (original poster) »

Well, I'm really glad I took your advice and ordered a valve replacement before starting the repair....my o-ring basically disintegrated to nothing, almost looked like red dental floss!
I don't have a vice, so I used two wrenches to take the old one apart and put the new one on. Couldn't get the elbow and discharge tube connection squared up. I put a ton of force into it and started to round it out so I just assembled it.
As you can see from the photo, it touches the insulation a bit but appears to be working great. Should I be worried about its position? The clear hose isn't impeded at all, but I could easily buy a vice from Home Depot and torque it out if need be.


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Peppersass
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#9: Post by Peppersass »

CelliniEVO wrote:Couldn't get the elbow and discharge tube connection squared up. I put a ton of force into it and started to round it out so I just assembled it.
As you can see from the photo, it touches the insulation a bit but appears to be working great. Should I be worried about its position? The clear hose isn't impeded at all, but I could easily buy a vice from Home Depot and torque it out if need be.
As long as the hose isn't kinked and the steam/water flow isn't impeded, you're OK.

That said, I should have warned you about this problem -- I've run into the same thing. I actually have several valve and elbow sets, and some line up reasonably well (i.e., brass nipple pointing left) and others don't. Sometimes the nipple ends up pointing to the back of the machine, the front of the machine or the right! I've resorted to playing with different thicknesses of copper washers to compensate. I don't know what's going on with this and haven't had time to figure out why some valve-adapter combinations work and others don't. It looks like the elbow and brass valve bodies are custom made, so maybe they cut the threads to match when they assemble machines, but can't do that for spares valves. I'm sure others know a lot more about thread cutting than I do and perhaps could comment.

twolane

#10: Post by twolane »

For what it's worth, this oring (http://www.espressoparts.com/S_28) is a great fit for an vacuum breaker. :D