The S1 Cafe - Helping Your Espresso Dreams Become Reality

Heres a brief introduction to cover some fears overcome. not sure if I will manage to post complete step by step with photos at this sitting.

Caveats

My great fear was knowing the internal rebuild components were graphite and I likened it to graphite in a pencil, fragile, break easy. I was worried about snapping the graphite components.

Fact; Graphite comes in various hardness's with a pencil being on the very soft end.

The 3 graphite components of pump are exceedingly strong as it took much fulcrum force with tools to remove the originals. This hardness graphite has a very strong compression tolerance/strength.

Was not that difficult to do. The only time elbow grease was needed was in removing the old graphite flanges albeit the first one came out very easily. The other operation that needed a little force was to compress the cover plate so the C clip could be reinserted.

The exploded view showing the proper assembly of the internal components specifically the pieces that create the watertight seal was not 100% clear on schematic but with some trial and error and great support from Fluid O Tech I figured it out.

Pro's and Con's;

Interesting, educational and fun. Save some money versus buying a new pump. The brass pump housing is not cheap, generally lasts forever and only needs an internal cleaning of debris and minerals. Shipping cost of pump higher due to added weight of housing vs light rebuild components.

Fear of breaking something and being stuck unable to make coffee. Learning curve. Need time to do it.


Step by step with photos to follow

Unplug

Turn off water supply

Remove 2 screws faceplate and remove faceplate

Turn on back
Pump exposed anterior view

Pump exposed on anterior view Bottom view pump access

Remove water inlet connection . 17mm wrench

Remove water outlet connection . 14 mm wrench

Remove motor-pump coupling collar
Remove pump. Dont misplace brass coupling that links pump shaft to motor shaft

Inspect and clean if need be the bearing area of motor collar. Here can see residue of aluminum corrosion from pump water leak. Ceramic bearing seen.

Water damage on coupling side of pump

Pump outer housing cleaned

Remove C clip . with needle nose plier or C clip tool. Note the clip tool must squeeze inward. I initially used the opposite tool applying inward pressure with a vise grip (not shown in photo).

C clip and metal cover plate removed to expose rubber O ring on front flange and front end of metal rotor
Remove rubber O ring

Remove old internal components. I used an motorcycle internal bearing puller and a socket set extension through coupleing side of pump. Rubber mallet helped. Some force required to get out old components most of which broke.

Internal bearing puller set for motorcycles

Vinegar water soak to remove minerals. Since I did not mess with adjustment valve nor replace its O ring I just used vinegar rather than a strong de mineralizing chemical.
Old internal components post removal

Original internal components that came out intact. Front graphite flange Metal rotor, 4 graphite vanes, alignment pin and 2 vane pins

Cleaned brass housing internally

WRONG WAY to install graphite seal ring on rotor shaft. In addition spring is missing.

Insertion of white ceramic disk in rubber gasket

Rotor inserted into back flange. Can see vane pin holes

Vane pins correct positioning depicted though not inserted into rotor yet. Vane pins inserted and in correct position . (flat sides touching. You also see graphite vanes correctly positioned in rotor. Note convex ends face outwards

Next place graphite liner (middle graphite component) over rotor vane assembly and than place graphite front flange on top. Rotate 3 graphite components so the 3 alignment slots become one. I used a small amt of scotch tape to hold assembly together. I cleaned any tape residue before final assembly. Fluid O Tech recommends isopropyl alcohol as a cleaner-lubricant for assembly as it leaves virtually no residue.


Carefully install the graphite seal-spring mechanism over the rotor shaft. Seal distance is about 0.72 inches. The small graphite seal ring touches the white ceramic disk to create the pump internal water seal while also allowing the rotor to spin. It is essential the small graphite ring surface be perfectly flat not damaged. Tiny indentations or surface defects can cause water leaks. Should this graphite seal surface become not flat you may fix it by using a #500 knife sharpening stone to eliminate gross imperfections and finish it with #1000 stone. I had a #1000 Japanese water stone available to use.

Carefully position the internal assembly into brass housing in the correct position while insuring the flange alignment pin is in place.

I used a gentle combination of hand and rubber mallet to get it in. Was not difficult. Once internal assembly in inserted you can push it in and feel the spring tension and release it and it pops up . Can see the rubber O ring above front flange and metal cover plate above it

Here is the action of spring shown in video attachment
https://youtu.be/Jt0m4qqsb28

With new rubber O ring on top of front flange and metal cover plate I used a C clamp to compress adequately enabling C ring reinsertion.You may need to squeeze C ring into recess, I used a vice grip.

Reattach pump in reverse order, turn on water and plug in power. Test.

Rebuild manual says pumps are typically bench tested so you may need to run it a bit. My pump shaft initiall a bit difficult to turn after cover plate compressed and C ring place but resolving on its own. No visible water leaking.

Rebuild manual shows pump bearing but the S1 pump does not have a bearing.

PS; You do not absolutely need the internal bearing pullers to do this rebuild.

May be possible to remove old graphite components without breaking by soaking in vinegar solution overnight as it may be mineral buildup causing the adhesion.

Can be tapped out from rotor shaft opening also.

What standard tool that I might already have can be used in place of the internal bearing puller?

What standard tool that I might already have can be used in place of the internal bearing puller?"
Some options;

Front flange and rotor and rotor components come out easily. Then you are left with #graphite liner and #graphite rear flange, mechanical seal and spring. Using hacksaw blade or equivalent cut into liner until near brass housing but avoid cutting housing. then can use a strong screwdriver or chisel to break graphite. Can also use curved nose pliers for this. Initially even with internal bearing puller it wasnt budging before I cut graphite.

The rotor opening can accept a screwdriver that can be angled to knock out the graphite.

Can also try the "secret bearing removal" trick by packing chosen cloth through shaft hole then using socket extension to tap down thus pushing graphite out. What I did also very helpful was to form a nice cushion cradle using a old bath towel.

https://www.youtube.com/watch?v=ggsEewAg2YM
https://www.youtube.com/watch?v=w62c4NQDwP0

One comment on oil/grease soaked rag trick to remove graphite. I would use a water soaked rag rather than oil/grease because you dont want oil/grease to find its way into the valve.

Where did you get the parts kit?

"Where did you get the parts kit?"


Fluid O Tech USA .. about 36 usd plus shipping



Fluid-o-Tech International, Inc. Tel 860-276-9270

161 Atwater Street Fax 860-620-0193

Plantsville, CT 06479 www.fluidotech.com

Since spanner wrenches are in nobodies tool box here's a simple way to get the pump cover off for those with the threaded cover

Sent from my SM-G950U using Tapatalk

Good idea and fast.

Below also look decent though requires a little time to make.