I saw a few older threads on this, but the forum software wouldn't let me add to those threads saying that they were "too old."

I have '99 La Pavoni Romantica, a somewhat jazzed-up (all brass, wood handles, dome covering boiler fill, etc) version of a La Pavoni Pro.

Since purchasing it, the steam wand has dripped. Not really a big deal, but annoying for sure. I've been keeping a shot glass there to catch the drips, but I'd really like to fix it. I've read various threads and suggestions for fixing it. I descaled the entire machine, then specifically descaled the entire steam valve assembly. I also cleaned the tapered male part of the steam valve shaft (end of the shaft where it seals against the steam valve body metal-to-metal) none of that fixed the problem. Upon further inspection, I can see where the female portion of the steam valve assembly is worn, with a little ridge of brass all around the opening where the male end of the shaft tightens (probably from over-tightening the steam valve shaft). So, I feel that ridge is preventing the male tip of the shaft from fully seating against the steam valve body and it allows steam/water/pressure to escape via the steam wand.

I've read a couple of threads about using a dremel tool to fix the problem, but given the depth of the steam valve body this would require some sort of shaft extension, or, a grinding bit with an extra long shaft--not sure if either of these exist.

I tried putting a small o-ring on the end of the tapered male shaft hoping the rubber could make a better seal, but it just slid down the shaft and did not make a tight seal. Then yesterday at the hardware store I was looking for a few rubber washers for our kitchen faucet, and I came across a type of washer that is flat on the one side, and has a small "shaft" of rubber on the other side with a hole in the middle. The hole just so happens to be the same size as the tapered end of the steam adjustment shaft. The flat side had a little lip on it that I trimmed off with a razor blade, then I stuck the washer onto the end the steam adjustment shaft with some high temperature silicone, and let it dry overnight. In effect, instead of metal on metal, the end of the shaft now has this rubber washer on it, and that it what makes contact with the female part of the steam valve body thus preventing steam from passing through. I installed it this morning, and pulled several shots, and so far it is working! I have no idea how long it will last, but even if I have to change it out once a month, it's better than the cost of a replacement steam valve body and the labor to change it out, and/or taking a dremel tool to the inside of the valve body. If it only last a few days, well........

One last thing, stopping the drip made a noticeable difference in my group temps! I suppose that they steam/water/pressure leaking out fooled the pressurestat into thinking that the unit needed more steam. After stopping the leak, my group held pretty steady at 185-195F even after being turned on for 30+ minutes. Before stopping the steam wand leak, my group (measured at the bell) would get up to 215F pretty quickly.

You must not be bleeding the system properly if this would change group temperatures. Trapped air in the boiler and in the space above the piston in these La Pavoni machines will result in a manifestaton of Dalton's law. (Each component of a mixture will exert its vapour pressure separately so that the total pressure is the sum of the partial pressures of all components.) Unless one properly bleed these machines temperatures will be erratic, and one will have to wait a LONG time for the group to warm sufficiently for the first shot. You can test for completeness of bleeding by the "olive jar" technique:

Bleeding Pressurestat lever machines. (Especially 2nd gen La Pavonis)

If you turn on a 2nd generation La Pavoni machine of any kind that group (unless it is leaking) will be no warmer than about 35C when the machine comes "up to pressure". If you touch it, it will only be warm. Essentially instantly after bleeding the boiler and group the temperature will shoot up so you will burn your fingers if you touch it!

You should be able to pull the first shot within two or three minutes of the machine's coming back up to temperature after the bleed.

You might think that not bleeding will result in better temperature control. However, there are always slight leaks and also the volume of vapour above the water in the boiler increases with each shot resulting in lack of control over the whole system when absolute control is essential.

I always bleed the system before pulling a shot both by opening the steam wand, and raising the handle and allowing a couple ounces of water to flow through the empty portafilter. It usually only takes my machine about 8-10 minutes to get up to temp and pressure to pull my first shot.

Back to your steam drip fix, do you have photos of the type of rubber washer you used? Awhile back I struggled with the same drip problem and had been trying unsuccessfully to create a gasket to metal solution. I've never liked the metal-to-metal steam wand arrangement in La Pavoni machines compared to gasketed versions on many others, including the Elektra Microcasa and the Olympia Express Cremina.

The vast majority of steam stop valves with any flow regulating characteristics when partially open are metal to metal tapered plug valves. Excessive crunching on them cuts the plug and then they leak. This wear/damage can be fixed with stem and seat replacement in the worst conditions or just stem replacement in the case of minor wear. It is a bit counter intuitive but steam is highly abrasive so once the valve leaks it slightly past maintenance time.

Gary, I grabbed the last one at the hardware store on the outside chance that I could make it work. Now that it seems to be a viable option, I'll go back to the hardware store and see if I can get some more of them, and I'll take some pics and post them here.

drgary wrote:Back to your steam drip fix, do you have photos of the type of rubber washer you used? Awhile back I struggled with the same drip problem and had been trying unsuccessfully to create a gasket to metal solution. I've never liked the metal-to-metal steam wand arrangement in La Pavoni machines compared to gasketed versions on many others, including the Elektra Microcasa and the Olympia Express Cremina.

Any time I'm in need of an O ring, gasket, washer, bolt, screw or whatever-other than piston seals-I check out the hardware stores first. I am usually able to find what I need or modify something to work. Much more handy and inexpensive than the specialty shops.

Glad you got it to work for you!

The only problem with hardware store O-ring is they may not be food safe/rated and often they are not rated for the high temperature meaning they will work for a while then disintegrate or turn rock hard.

I'll be interested to see the shape of that gasket. Perhaps one can be found or made of the appropriate high temperature food grade material.

High temp you can do, food grade will be H-1 at best which is incidental contact, but finding both in an elastomeric material that has an acceptable durometer value will be the hard part. Finding an acceptable material that is not NSF will be relatively easy though.