Announcement

Collapse
No announcement yet.

1976 La San Marco Tipo 75 two group

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 1976 La San Marco Tipo 75 two group

    The third and last machine from my most recent shipment is this La San Marco Tipo 75. I intentionally wanted a two group as I like using them in the winter and fall. Perhaps down the road I can fit in an Export version . Initial state looks pretty promising on the outside. As a two group machine it has an additional steam valve and a cup tray valve compared to the 1 group. The only damage I can note is a small dent in the body panels on the top left of the machine when looking from the front. It was already present when I purchased the machine and did not occur during transit. The traffic cone orange panelling really sticks out but it has splotches of random paint on it. I am still debating whether to keep the panels original. The LSM 75 uses the same knobs and portafilters as my earlier LSM 6X machine except for the water inlet knob, which is a button rather than an actual tear drop knob.
    Click image for larger version

Name:	front initial state.jpg
Views:	317
Size:	248.8 KB
ID:	918882 Click image for larger version

Name:	outside back.jpg
Views:	291
Size:	212.4 KB
ID:	918881 Click image for larger version

Name:	outside back detail.jpg
Views:	286
Size:	236.8 KB
ID:	918883 Click image for larger version

Name:	Lion emblem.jpg
Views:	285
Size:	169.9 KB
ID:	918880 Click image for larger version

Name:	San Marco sign.jpg
Views:	425
Size:	103.6 KB
ID:	918879

  • #2
    Click image for larger version

Name:	outside side.jpg
Views:	312
Size:	256.5 KB
ID:	918885 Click image for larger version

Name:	outside corner.jpg
Views:	287
Size:	220.2 KB
ID:	918886 Click image for larger version

Name:	small damage.jpg
Views:	277
Size:	241.4 KB
ID:	918889 Click image for larger version

Name:	detail front.jpg
Views:	273
Size:	220.5 KB
ID:	918887

    To take off the panels you need to start in the front and remove the two panels that cover the group heads. Four screws secure the vertical front panel to the frame, while three screws (one was missing) secure the top panel to the front panel. Taking off these panels reveals two styles of groupheads. The left one has some play in the lever fork so I will be inspecting that one closely when I take it apart fully. Both groups have ID numbers stamped on the lower group piece, 9685 for the left and 7187 for the right.
    Click image for larger version

Name:	cup tray off.jpg
Views:	271
Size:	293.9 KB
ID:	918888

    Comment


    • #3
      Click image for larger version

Name:	front panels off.jpg
Views:	334
Size:	295.3 KB
ID:	918891 Click image for larger version

Name:	front group and valves.jpg
Views:	283
Size:	258.0 KB
ID:	918893

      To take off the rear panels a slotted bolt and two phillips screws need to come off on each side. The phillips screws also secure the backsplash to the machine, and the slide it off the hot cup tray valve knob needs to come off too. Once done the back panels come off by pushing the whole assembly forward a bit then lifting it up because there is a lip on the bottom rear of the assembly that slips into the frame for stability.

      Click image for larger version

Name:	panel screws.jpg
Views:	284
Size:	209.5 KB
ID:	918892 Click image for larger version

Name:	backsplash off.jpg
Views:	283
Size:	274.9 KB
ID:	918895

      Inside I realized the pstat bracket was in two pieces, leaving the pstat hanging just by its pipe. This machine has an ANCC or similar number, but it does not use the same one as the Lombardy brands (like Faema, Gaggia, etc) because each region of Italy had their own ANCC/equivalent number list. This is why even though the machine is from 3 February 1976 the ANCC number is only 55338 (the San Marco ID tag is 26406) when my similarly aged 1979 Gaggia LL's ANCC number was over a million.

      Click image for larger version

Name:	panels off side.jpg
Views:	287
Size:	295.1 KB
ID:	918894

      Comment


      • #4
        Click image for larger version

Name:	panels off back.jpg
Views:	291
Size:	258.9 KB
ID:	918899 Click image for larger version

Name:	panels off top.jpg
Views:	284
Size:	286.8 KB
ID:	918900 Click image for larger version

Name:	Boiler numbers.jpg
Views:	286
Size:	168.4 KB
ID:	918898 Click image for larger version

Name:	ID tag.jpg
Views:	315
Size:	308.6 KB
ID:	918897

        The boiler lid came off without too much hassle. I used my little impact driver to get the bolts loose, and nothing was really stuck even though there was a decent amount of surface rust on the bolts. There was old water in the boiler that drained out after taking the lid off.

        Click image for larger version

Name:	wiring.jpg
Views:	284
Size:	248.4 KB
ID:	918901

        Comment


        • #5
          Click image for larger version

Name:	lid off.jpg
Views:	301
Size:	242.8 KB
ID:	918903 Click image for larger version

Name:	old water in boiler.jpg
Views:	276
Size:	294.7 KB
ID:	918906

          The valves and pipes all came off too without issue. The valves themselves differ a little in how the pipe attaches, allowing the pipes to swivel, but the gaskets inside are the same as my LSM 6X and modern machines today. The groups came off after, and I left the group flanges attached to the boiler due to the amount of scale deposits accumulating from the old leaky gaskets. I will descale first before attempting to take those off.
          Click image for larger version

Name:	valve detail.jpg
Views:	277
Size:	185.9 KB
ID:	918904 Click image for larger version

Name:	groups off.jpg
Views:	282
Size:	338.8 KB
ID:	918907 Click image for larger version

Name:	boiler and flanges.jpg
Views:	275
Size:	259.0 KB
ID:	918905

          Comment


          • #6
            The feet came off, which are the same shape as the LSM 6X. The bolts are horribly rusted so they will likely be replaced. At this point I was satisfied to the progress I made stripping the frame and moved everything into the basement.
            Click image for larger version

Name:	feet.jpg
Views:	280
Size:	262.0 KB
ID:	918912 Click image for larger version

Name:	feet off.jpg
Views:	295
Size:	205.7 KB
ID:	918909 Click image for larger version

Name:	stripped frame.jpg
Views:	282
Size:	292.9 KB
ID:	918913


            Further disassembly will occur soon
            Click image for larger version

Name:	groups and pipes.jpg
Views:	278
Size:	213.7 KB
ID:	918911 Click image for larger version

Name:	panels.jpg
Views:	281
Size:	206.8 KB
ID:	918910

            Comment


            • #7
              I ran into a really, really bad problem for one of the groups during disassembly. First off I was getting the valves apart along with the other grouphead without issues. The valves allow the pipes to swivel, and are compressed by two conical teflon gaskets and a spring to keep the seal. There was a lot of grease on all the valves.
              Click image for larger version

Name:	swivel valve.jpg
Views:	285
Size:	167.9 KB
ID:	919045 Click image for larger version

Name:	swivel valve gaskets.jpg
Views:	256
Size:	188.5 KB
ID:	919047 Click image for larger version

Name:	hole for valve rod.jpg
Views:	255
Size:	193.7 KB
ID:	919046 Click image for larger version

Name:	greasy valve 1.jpg
Views:	251
Size:	195.8 KB
ID:	919048 Click image for larger version

Name:	greasy valve.jpg
Views:	256
Size:	208.4 KB
ID:	919049

              Comment


              • #8
                One group was fully taken apart. The pistons are the newer style with the big fat v gasket and teflon guide + brass ring. They are still designed to fully relax the spring before the compressing nut comes off the threads of the piston rod.
                Click image for larger version

Name:	disassembling 1st group.jpg
Views:	253
Size:	263.5 KB
ID:	919052 Click image for larger version

Name:	20220701_102700.jpg
Views:	254
Size:	206.9 KB
ID:	919053

                This is where the real big issue lies. The second group was mounted for disassembly, and I saw the piston rod start turning with the piston. This is not good, and with some inspecting I realized the little pin that prevents this from occuring failed, and I was actually unscrewing the piston rod from the top. This is really bad because there is far less thread for the spring to relax, and the group is not designed to come apart like that with the spring still installed. The piston is more stuck than the upper rod threads which is also an isssue because I cannot access the spring compressing nut that allows me to safely decompress the spring.
                Click image for larger version

Name:	second group piston rod failure.jpg
Views:	281
Size:	150.0 KB
ID:	919051 Click image for larger version

Name:	second group piston rod failure 1.jpg
Views:	251
Size:	174.0 KB
ID:	919054

                Comment


                • #9
                  After speaking with someone who experienced this same issue I decided to try my luck and fully unscrew the rod from the top. I zip tied (these are pretty heavy duty but I will not openly recommend others doing this without understanding the risks and padding themselves in protection) the spring so they would hold back some of the force as the spring relaxed, and it seemed to do a good job as the piston and springs simply fell out without launching themselves when the thread ended. The other person said his piston dented a car in the garage from the force of release. I immediately placed the spring in my decompressor and relaxed it without issue.
                  Click image for larger version

Name:	removed spring.jpg
Views:	251
Size:	254.9 KB
ID:	919058 Click image for larger version

Name:	decompressed spring.jpg
Views:	243
Size:	216.0 KB
ID:	919057

                  Looking at the eye piece there was definitely a little pin that normally secures the piston rod, but it failed/sheared off and left some marks in the process. The piston is really stuck on the rod and I have not been able to get it loose yet. I will need to work on that more but I am just happy I was able to get the group mostly apart and not potentially need to replace an entire upper housing.
                  Click image for larger version

Name:	piston eye.jpg
Views:	261
Size:	216.3 KB
ID:	919059 Click image for larger version

Name:	piston eye detail.jpg
Views:	274
Size:	176.0 KB
ID:	919056

                  Comment


                  • #10
                    __________
                    Click image for larger version

Name:	piston rod threads.jpg
Views:	257
Size:	163.5 KB
ID:	919062 Click image for larger version

Name:	stuck piston.jpg
Views:	280
Size:	185.9 KB
ID:	919061 Click image for larger version

Name:	stuck piston detail.jpg
Views:	255
Size:	200.6 KB
ID:	919064 Click image for larger version

Name:	mostly disassembled groups.jpg
Views:	255
Size:	244.2 KB
ID:	919063

                    Comment


                    • #11
                      I managed to unscrew the piston finally. Both the piston and the spring compression nut were tightened way too much. I had to strike my spanner wrench with a hammer to unfreeze the threads, and before that I also did a few heating and quench cycles. I also had to tilt my spanner at an angle because the notches on the face of the piston are not cut parallel to the face, but rather at an angle. I also fished out the broken pin from the top. Seeing how tight the piston was screwed in I am not super surprised it snapped, but hopefully I can clean up the piston bore and related parts without issue. The random chrome flakes are from the piston bore, and it crumbled out in pieces during disassembly.
                      Click image for larger version

Name:	20220701_145957.jpg
Views:	251
Size:	198.9 KB
ID:	919074 Click image for larger version

Name:	20220701_150253.jpg
Views:	271
Size:	209.5 KB
ID:	919072 Click image for larger version

Name:	20220701_150846.jpg
Views:	249
Size:	220.8 KB
ID:	919073

                      Comment


                      • #12
                        I figured out why there was some play in one of the groups (the older looking one that was originally on the left), and that is because the piston rod is loose, and the internal pin was failing. It was taken out in two pieces. I also had to clean the threads from the metal glitter that was created from the pin that completely failed.
                        Click image for larger version

Name:	borken 2nd pin.jpg
Views:	240
Size:	171.8 KB
ID:	919227

                        In the meanwhile I did my degreasing and cleaning regime for the valves and relevant group parts. I had to do multiple rounds in the tumbler due to the large number of parts I was cleaning. Some parts are plated so they will not give as much shine. There's various other parts in the mix like the group and flange nuts, a few body panel screws, the heating element nuts, etc.
                        Click image for larger version

Name:	degreasing parts.jpg
Views:	243
Size:	241.6 KB
ID:	919229 Click image for larger version

Name:	tumbler parts.jpg
Views:	242
Size:	221.8 KB
ID:	919228 Click image for larger version

Name:	cleaned LSM 75 parts.jpg
Views:	243
Size:	431.7 KB
ID:	919230

                        The manometer actually has a more recent date than the machine, 5 July 1977. I wonder if the original one failed. The bezel was also missing one of two tiny screws that secure the bezel to the manometer.
                        Click image for larger version

Name:	5 July 1977.jpg
Views:	270
Size:	129.9 KB
ID:	919226

                        Comment


                        • #13
                          I investigated the frame a little more too because I have seen on other San Marco machines the group/flange studs are not metric. Looking into it the studs are actually just a regular M8 x 1.25 thread, and I was easily able to thread a bolt onto an original nut and thread an M8 nut onto an original stud. The studs screw into the frame and can come out, and I got them all taken off this week. I measured on my LSM 6X and that one does have an SAE thread for the group studs, 5/16" 18 TPI
                          Click image for larger version

Name:	taking of frame stud.jpg
Views:	233
Size:	147.8 KB
ID:	920268
                          The lower skirt pieces come off via six screws, two on each front corner and one on each rear corner. The skirt is made of two pieces, one covering the front and sides and the other piece covers the rear and also secures the little foot frame pieces. The two 'feet' pieces I am referring to simply slip on over two beams at the bottom of the frame, and are only secured by the four aluminum feet I took off earlier. However, there was some rust from the frame that fought me while slipping the pieces off.
                          Click image for larger version

Name:	rear screw lower skirt.jpg
Views:	205
Size:	139.0 KB
ID:	920269 Click image for larger version

Name:	front screws lower skirt.jpg
Views:	202
Size:	159.4 KB
ID:	920270 Click image for larger version

Name:	front skirt off.jpg
Views:	203
Size:	265.3 KB
ID:	920272 Click image for larger version

Name:	foot frame off.jpg
Views:	205
Size:	242.6 KB
ID:	920271

                          Comment


                          • #14
                            I had to wait for the arrival of a big (and I mean BIG) 35mm wrench to take off the dipper tubes. The design of the boiler did not allow me to fit my adjustable wrench and be able to exert enough torque to loosening the big 3/4" BSP dipper tube threads. With the 35mm wrench I could easily fit the tool and knock both tubes loose with my deadblow hammer. I am able to lock the outer fitting onto my vise which allowed me to exert the necessary force. The dipper tubes are designed differently from the modern San Marco dipper, with female threads for the old one instead of a male thread for the modern tubes. You can also see the LSM 75 tubes are a little longer than the LSM 6X, shown on the left.

                            Click image for larger version

Name:	unscrewing dipper tubes.jpg
Views:	206
Size:	271.0 KB
ID:	920278 Click image for larger version

Name:	dipper nut on vise.jpg
Views:	252
Size:	192.6 KB
ID:	920274 Click image for larger version

Name:	dipper tubes off.jpg
Views:	211
Size:	185.1 KB
ID:	920276 Click image for larger version

Name:	compare to LSM 6X.jpg
Views:	213
Size:	185.9 KB
ID:	920277

                            With all the pieces apart I spent most of today cleaning them and taking off the nasty old gaskets. I had to take picks and gently poke off the gasket residue, and with some wire wheeling, citric acid baths, and magnetic tumbler they are all cleaned up.
                            Click image for larger version

Name:	tumbler in use.jpg
Views:	209
Size:	188.3 KB
ID:	920275

                            Comment


                            • #15
                              Click image for larger version

Name:	scraping old gasket.jpg
Views:	213
Size:	192.6 KB
ID:	920281 Click image for larger version

Name:	cleaned dipper and flanges.jpg
Views:	213
Size:	227.1 KB
ID:	920282

                              The boiler is cleaned up to my satisfaction. A nasty gasket was taken out of the boiler lid and I am still cleaning that up.
                              Click image for larger version

Name:	cleaned lsm 75 boiler.jpg
Views:	214
Size:	282.0 KB
ID:	920283 Click image for larger version

Name:	yummy gasket.jpg
Views:	233
Size:	214.7 KB
ID:	920280

                              Comment

                              Working...
                              X