Changing CMA lever seals

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#1: Post by DonFelipe »

Decided to change the seals and the cylinder liner its pretty dirty (compared to Paul Pratt YT explanation video)
Whats the reason for the dirt accumulation?
How to remove it?

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#2: Post by Chert »

Unless your water source has dirt somehow, you should not have dirt there. Scale is a possibility. You removed the liner or do you see the "dirt" when looking up into the group? Do you have pictures of that too?
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#3: Post by DonFelipe (original poster) »

Didnt remove the liner. I think its only a hit of scale and not dirt..
How to remove the scale from the liner?

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#4: Post by baldheadracing »

Clear seals - never seen those before.

I don't see any dirt, a bit of white scale, but nothing serious.

The black appears to be Copper(II) Oxide. If you can't scrape the black off with your fingernail, then it is Copper(II) Oxide - which you want to keep as it is protective. If you really want to remove it, then Citric Acid works. You'd be exposing the brass, but that's only a small bit of brass and the Copper(II) Oxide should come back fairly quickly (again, a good thing).

As an aside, that doesn't look like a CMA group to me.
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#5: Post by DonFelipe (original poster) »


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#6: Post by espressotime »

Transparent seals.Now I' ve seen it all. :D
It' s a clean machine.

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#7: Post by mrgnomer »

You could use a vinegar soak as well to remove scale with a good rinse. Depending on the machine and whether you use a puck screen grounds and oils can get sucked up into the group. It can look like dirt.

+1 on oxide not being a bad thing.
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