Need help cleaning piston and group

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#1: Post by Jmalpica »

Hello friends, I'm the guy with the mexican-made lever machine. Right now I'm with almost everything in an citric acid bath for heavy descaling but I have some questions regarding the piston cleaning. It has some old grease stuck in there but right now I don't have any new gaskets so removing them is a NO NO. I already bought some Molykote 111 but well, what advice can you give me??

The group is already off the machine body and piston out. Should I put them also in the citric acid or maybe some dishwasher soap??? (old pics attached)

Thank you so very much in advance!!!


#2: Post by zfeldman »

Am I missing something?
That looks REALLY clean already.
Wipe it with a rag, put on fresh grease, call it a day?

Jmalpica (original poster)

#3: Post by Jmalpica (original poster) replying to zfeldman »

The piston has some brown-ish grease, also the piston on the inside, like really old stuff, maybe not seen on the pics =(


#4: Post by miab »

Soap , old toothbrush, scrub, rinse. Regrease. Don't use acid bath when you don't have to. Keep acid wash away from chrome.

That machine needs heater cartridges in group. It's a remote dipper. Needs constant use for proper group temperature as it is. It's ok if in busy cafe.

Jmalpica (original poster)

#5: Post by Jmalpica (original poster) replying to miab »

Thanks, I will do that!! Regarding the temperature, I saw in other post some way to add a PID controlled silicon heater band to the bottom section of the group, what do you think??

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#6: Post by beer&mathematics »

You can soak the entire group in JoGlo and it can soak overnight and you'll do a lot of good with a toothbrush. If seals feel fine you can re-apply Dow111 and give it a whirl
LMWDP #431


#7: Post by miab »

Yes, the PID with your choice of heating the group electrically is the right choice. There are advantages to the remote dipper. You need a fine balance of heating the group and temperature rise with hot water entering the group though. Through trial you can get there.

BTW, there nothing wrong and even beneficial to have a coating on your brass exposed to hot water. There is lead in your brass. As long as the 'grime' doesn't impart a taste to your coffee, your good.