Removing the knob on a La Pavoni steam valve
This post documents how I went about removing the knob from the shaft of the steam valve on my La Pavoni lever coffee machine.
I've had my La Pavoni PL lever espresso coffee machine for just over a year, and I'm extremely happy with it. Recently I ordered some wooden replacement handles for it from a vendor on Etsy and when they finally arrived I set about replacing the factory standard bakelite handles with the wooden ones.
Replacing them was easy except for one item - the knob on the steam valve shaft. The existing one was held in place by a metal split pin and seems to have a reputation of being hard to remove. I couldn't figure out the best way either; while I'd learned how to remove the shaft itself from this video on YouTube: La Pavoni Lever Machines: How to Remove the Steam Valve Shaft I couldn't quite figure out how to remove the knob itself.
So I asked on the r/espresso subreddit and the user Dr_Procrastinator gave some very helpful advice in a reply.
Having obtained a small and inexpensive set of nail punches from a local hardware / DIY store (B&Q Ashton, £5.25) earlier this week, I set about the task this morning, and thought I'd share some photos as it might help someone else.
Removing the shaft
First I removed the shaft, by simultaneously unscrewing it using the knob, and unscrewing the silver threaded nut with a spanner.
I just kept on unscrewing the shaft until it came completely loose and I could pull it out with the last few turns; there was a bit of resistance (from the gasket, I guess) but not much.
This is what it looks like once removed:
Removing the knob
I needed to hammer the split pin out through the hole in the knob, so I used a folded towel to support the shaft, and laid the knob within / on top of the thumb-hole of a heavy-duty chopping board; in this photo you can see the hole marked with the arrow. This gave enough support and stability for the next step, and it also afforded enough gap underneath for the pin to start coming out of the bottom (it wasn't a worry though as the pin came through very slowly with a lot of effort!).
While the shaft and knob were supported, I could then use the appropriately sized punch with a small hammer to gently but firmly tap down on the split pin, driving it out slowly.
It took a while - I was going gently and it took me a few minutes. Once the pin was sticking out enough through the end, I pulled it out with a pair of pliers (it was quite a struggle).
While tapping the pin punch into the hole, the rim cracked a little and a bit of bakelite flaked off, but I think that is not unusual in such conditions.
Here's the final result:
Fitting the new knob
Ironically, all this effort has been somewhat in vain, as the new wooden knob has a tiny hex nut that you are supposed to screw round and down into the shaft to hold it firm. But while I had plenty of Allen keys around the house, not one of them fitted snugly and I couldn't get a decent torque to turn the screw into the shaft. This meant that this securing mechanism - that relies on sheer force into the metal shaft - was useless.
I guess once I find an Allen key that fits, I can try to screw it in tight enough for the knob to hold and not slide around the shaft when I'm using it to open and close the steam valve.
Until then, I've gone back to the bakelite knob ... with the pin pushed back through, but not all the way so I can get it out more easily next time.