1976 La San Marco Tipo 75 two group - Page 3

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IamOiman (original poster)
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#21: Post by IamOiman (original poster) »

truemagellen wrote:If you need to borrow please let me know
I decided to just buy the tool because of what I'll explain below.

I got my frame back from my Metal guy. It was powdercoated a black with 80% gloss, really shiny and nice looking. I also had him clean up the lower stainless steel panels that slip on the bottom of the frame, the boiler lid, and the corroded feet. The o ring I am trying out fit extremelly well, and it is a perfect snug fit inside. I am really optimistic it will work with this boiler lid style. Please don't mind the Marte missing its body panels in the back, that is how I found it best to move it without assistance.

I assembled the two groups when I received my Eevad order containing the last parts needed to begin. I first started with the lower groups and installed the preinfusion valve + one way valve. The former is a little difficult to install due to the strong springs necessary to keep water from escaping from the boiler when pressurized. I had to push down while turning the threads to get them to engage. The one way valve was easy enough to install, and they tightened perfectly in the correct position.

The upper group starts with the lever fork and rod assembly. I was able to reuse the original bearings after cleaning and regreasing them. The roller pins will stick to the bushing when the tacky grease is applied. There is a lever fork pin that is pressed through the bushing and pins. My ball bearings were made in the USSR, and this is not the first time I've seen that on espresso machines.

The felt washer is stuffed in a recess in the upper group housing and the piston rod can be inserted then secured with the bearing bolts. The springs can be installed after, and I had to compress the big spring about 0.5 inches to allow the spring nut to thread on. At this point the upper group is inserted without the piston into the lower group because the fat piston v gasket flares out too much to be inserted from above. Thus it needed to be screwed in below, and is why I decided to just buy the tool for future maintenance. I was able to hand tighten the pistons enough they are when the groups are standing upright for the short term.

With that they are both assembled minus the portafilter gasket and showerscreen. The preinfusion lever had the roller pins replaced but they are otherwise in good shape. There is a tiny bit of play with the left group due to wear but it should not impede function. I did however need to use loctite instead of a rod pin for the same group because it screws tighter than the pin hole can align properly.

Using a spice grinder violates the Geneva Convention
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#22: Post by truemagellen »

USSR bearings, a gentle reminder of time :lol: