Refeathering the Peacock - Pavoni head gasket replacement

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

Postby srobinson » May 15, 2005, 10:12 am

DISCLAIMER: ELECTRICITY CAN KILL YOU. IF YOU UNCERTAIN ABOUT WHAT YOU ARE DOING, STOP HERE. YOU ALONE ARE RESPONSIBLE FOR YOUR OWN SAFETY. IF YOU CHOOSE TO CONTINUE, YOU ASSUME ALL RISK AND RESPONSIBILITY. REMEMBER TO DISCONNECT THE APPLIANCE FROM ITS POWER SOURCE BEFORE WORKING ON IT.


One of the true joys of owning a Pavoni machine is the manual nature of it. Pulling that big handle every morning becomes part of your daily coffee ritual and with the simple nature of the machine you form a tight bond with it. With the simplicity of the machine you not only get to control almost every facet of the espresso process, but it also makes the machine very accessible to the owner when repairs are needed. In this short report, we will cover the most common maintenance on the machine which is replacing the head gaskets.

The suggested interval on this service is annual, but I had severely lapsed on this service until I started noticing slipping during the pull and difficulty in raising the handle. Also some infrequent hissing where the group head mates the boiler also was a clear indication that it was time to break out the tools.

All replacement parts are orderable from http://www.espressoparts.com and for this procedure on a Euro piccolo, the parts needed are:

36, 39, 40, 41, 43(2), 46 from the following diagram:

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Steve Robinson

LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:17 am

The first step in replacing the head gaskets is to find a willing victim for the procedure. In this set of posts, I will be using my trusty 9 year old Euro piccolo

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Step 1
The first step that you want to do is to remove the lock nuts on the core plunger stem. 14mm wrench will do. It is advised to do this step first before removing the handle or you will find that the plunger stem will rotate.

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Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:19 am

With the lock nuts removed it is now time to remove the handle. With pliers, carefully remove the lock washers and the two pins should easily push out. Please note the position of the two holes on the handle since it is possible to install them upside down which will result in water not entering the group head. Higher hole in the back and lower in the front.

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Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:21 am

With the handle removed it is now time to remove the group head from the boiler. For this step a 10mm wrench will do to remove both screws. At this point you should be able to pull the whole group head off of the machine.

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Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:24 am

With the group head now off, it is time to remove the plunger and the group head screen. Please note...DO NOT USE A SCREWDRIVER! Damage can occur. The best way to do this is to invert the group head and carefully press the threaded stem until the basket breaks free of the group head gasket.

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At this point you should have all the parts free to begin the gasket replacement process...and some messy parts that will need cleaning before you begin to wrestle them. Time for a little elbow grease to clean everything up. A good inexpensive cleaner is undiluted dishwashing detergent. Cleans fast and rinses with no residue.

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Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:29 am

The first parts to replace are the upper seal and brass retainer ring in the group head.

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Special tool needed here are spring clip pliers, but they are readily available at any auto parts store or at Sears. A great diagram from The Unofficial Pavoni Page that shows how these three parts go together

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(Image courtesy of David Jenkins)
Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:33 am

Now the fun begins on replacing the piston gaskets. These are the two major gaskets on the piston head. To remove the old ones, cut with a razor and please note the position of the Vs in the gaskets. Vs... Always point away from center. Here are two pictures of the old gaskets.

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Note the V grooves

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Now to insert the new ones. I found it best to heat both with warm water and to start with V grooves facing in the right direction and then slowly working around the piston. This is the hardest part of the process since the gaskets want to turn, but get them hot and take your time and they will pop into place. When done it should look like this:

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This is also a good time to make sure that your piston is firmly screwed into the piston shaft. If loose then this will hamper water flow as well.
Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:35 am

In this step you put the group head back together. If your gaskets were really worn, you will notice that you may have a bit of a challenge on your hands getting the piston back in the group head. I have found that water and slowly turning the piston will get it started. You can also try a light coat of food grade lithium grease as well. The piston in the Pavoni does not need grease to operate, so only apply enough to get the seals past the opening. Once the first one begins, then the second is easy.

Once the piston is inserted it can be fully pulled up using the lock washer on the piston shaft. Once in proper position, put the screen head in place and then insert the new head gasket. Carefully push into place with either the tips of your pliers or with a dull knife. Once in place you may want to test locking the portafilter to ensure that everything fits.

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Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:37 am

The final gasket to replace on the group head is the one where it meets the boiler

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This gasket easily pops out with the tip of your razor and the new one slides on.
Steve Robinson



LMWDP #001

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srobinson

Postby srobinson » May 15, 2005, 10:38 am

Everything should install easily in reverse order:

° Group to boiler. Do not over torque the screws
° Pins into handle...remember position
° Lock washers on pins
° Cap screw on piston.

At this point you are ready to give it a test. The handle should be easier to lift, there should be no slipping on pulls with very finely ground coffee and the action should really feel like a new machine.

Now polish the peacock and pull a great shot in celebration of your handiwork. Enjoy.
Steve Robinson



LMWDP #001