The little guy - Steam Pin

The steam knob is connected to a pin with a conical end that stops the steam flow to the steam arm.  If this pin isn't seated properly, steam will leak out, which will lower the pressure for the milk and also the pressure for the coffee extraction.

The most common cause of leakage (especially in areas with high mineral content in the water) is calcification from the dried steam that builds up and stops the pin from closing properly.  The first thing to try is closing it three or four times by hand tighter than you normally would. This can often break off the minerals. 

If this doesn't work, then it is possible that the steam pin might have worn and will need replacing.  

To access the steam pin:

1. Insert a Phillips head screwdriver into the end of the Steam Knob and unscrew the screw completely.
2. Slide off the  Steam Knob.
3. You may be able to unscrew the Steam Valve Collar without removing the Steam Collar Insulator first. Attempt to unscrew them both together by hand. If that does not work, then go to steps 4 and 5.
4. Remove the Steam Collar Insulator. This can be done by hand.
5. Unscrew the Steam Valve Collar using your hand by turning it counterclockwise. If your machine is old and has not been cleaned recently, you may need to use some pliers. Do not use pliers directly on the  Steam Valve Collar, as it will scratch the surface.
6. Unscrew the Steam Pin using your hand by turning it counterclockwise.  If your machine is old and has not been cleaned recently, you may need a small spanner.
7. To re-assemble, repeat the process in reverse.