I recently heard about a GS3 retrofit kit for the vacuum breaker valve and ordered it from LM. The vacuum breaker has caused some people major problems, including failure, with water entering the electronic brain box (not a cheap repair). I have had to take my vacuum breaker off a few times because of intermittent hissing when it is up to temperature. I have soaked it in vinegar and it has continued to function properly. The new kit can be seen on the GS3 parts list on the LM site. Its interesting looking at all the pages. There have been a number of parts changes and the catalog indicates when new parts started to be used according to machine serial number. For example there is an antivibration adaptor kit for the pump starting with S/N 831.
Interesting stuff.
Rob

I installed the new-style vacuum breaker a couple of weeks ago. I'm not completely sure, but I believe the valve seat has a teflon coating to resist mineral buildup, which should reduce the frequency of maintenance. The breaker also has a 90-degree hose barb from which a tube can be run to the drain box. This prevents any water or steam exiting from the valve from getting inside the machine and possibly dripping into the brain box.

The parts diagram shows a barbed termination fitting for the tube that passes through a hole in the frame above the brain box near the drains for the steam and coffee boiler OPVs. Rather than drilling a hole in the frame for the fitting, a T-fitting can be used to connect the tube running from the vacuum breaker to the tube running from the steam boiler OPV.

The retrofit is relatively easy if you have the proper metric tools. I took photos of the installation and will post them soon.

I highly recommend this update to owners of GS/3s with serial number 1169 and earlier. You should be able to order the kit from your dealer.

As for the anti-vibration kit, it's my understanding that it can't be retrofitted to older machines because the pump won't clear the left side panel. Evidently, the chassis cutout for the motor was relocated to accommodate addition of the bushing.

I "outboarded" my pump and motor to completely eliminate noise and vibration. I also added a motor on/off switch for manual line-pressure preinfusion. Removing the motor from the GS/3 is a major undertaking, so I bought a spare motor and just relocated the pump. I have photos of that project as well, and will post them when I get a chance.

Dick,
Thanks for the info. I agree, I think this is an important mod.
As for vibration, I have been able to get rid of just about all the vibrations. I used the longer hose from the pump which helped, a little dampening material in a few locations, and custom glass side panels. I think some of the vibrations were caused by the stock side panels, which I think are ugly anyway.
Rob

Yes, the stock side panels contribute to noise and vibration. It can vary depending on how much you torque the brass nuts under the decorative nuts.

I've removed the brass nuts altogether. My understanding is that they're there only because lab certification dictates that a tool be required to remove the panels. The noise level may be lower without the nuts and you'll be able to quickly remove the side panels for inspection and maintenance without getting out the socket wrench.

It's interesting that glass side panels reduce the noise level. LM is now selling branded glass side panels for the GS/3. It would be interesting to know if they reduce noise as much as your custom panels. The glass panels are expensive, though ($500 for LM panels, $400 for aftermarket panels.) It was much cheaper for me to buy a second motor ($169) and outboard the pump.

My custom panels were expensive (in the $500 range), but they are so cool and worth every penny. Smoked glass with etched GS3 logo. Don't know why LM doesn't make any this nice? IMO, their glass panels are kinda ugly.
Rob