Hello A. Frew:
Thanks a lot for chipping in, I appreciate your taking time to do so.
Alan Frew wrote:
This whole thread seems to me to be a "why the hell would you bother?!!" issue.
Your interesting articles were my very first immersion into the workings of espresso machines and while I have nothing but the highest regard for your experience and expertise in the matter, I must respectfully say that I'm not too sure that I can concur with your opinion that it's a "why the hell would you bother?!!"
Not wanting to polemise, I have the impression that there are at least two
points of view to this matter.
Please humour me for a bit while I ramble on.
One point of view is yours and I can only say that it makes perfect sense.
I see the tipical scenario as being one where a client of yours sends you a vibe pump equipped machine with a problem for you to solve. You check it out and it ends up being the vibe pump that is acting up. Quite understandably, your interest is that the repairs you have been entrusted with be done perfectly, in the shortest possible time and within the the most reasonable price bracket. This would of course include not only the parts to be replaced but also shop time, whatever your company's parts and labour warranty costs you and your company and last but not least
, the protection of your well earned reputation, which I would say is one of your most valuable assets.
Viewed from within the scenario described above, your point of view merits attention and is obviously technically and commercially justifiable. Swapping out a problematic pump will cost your client less than having a specialised technician take it out, strip it, see what's wrong, find parts from another one or from a rebuild kit, test it, put it back together, put it back in, test it in place, etc. and go all over it again in the eventuallity that once put together it does not work well or meet your specs.
Besides all this, putting in a new pump means that it will surely not fail under your warranty period, limiting your risk to the extent of your tech staff's experience and expertise, which I am sure is more than ample.
Thus, like I say above, your point of view makes perfect sense.
The other point of view is that of fellow member dracon or even myself. (Yes, I've been there too ...)
I see the tipical scenario now as being one where the owner of a vibe pump equipped machine with a problem (which coincidentally also
ends up being a vibe pump that is acting up) cannot, does not want to or for whatever motive (there can be many) will not send it in to a shop for repair.
Being an Ulka pump a simple enough device, having reasonable manual dexterity plus the required tools and the obviously needed DIY drive, he proceeds to dismount the pump and take it apart only to find that a) it is scaled stuck and while cleaning it, incurs in the mistake of not being careful enough (no, there's no such thing as careful enough here) and simply loses one of the small parts inside the pump (that damn little white plastic ball comes to mind), or b) that the mushroom valve has deteriorated, does not seal properly and is in need of replacement.
Viewed from within this second scenario, dracon wanting to get a replacement part (which in the case of the MV or PB probably costs less than $0.05) also merits attention and is certainly justifiable, as from his point of view he cannot see it (neither can I) as something reasonable to throw out a pump that is in perfect shape just because a small part with a negligible price tag has deteriorated and is unobtainable, being the only way out to pay for a brand new pump plus all the associated costs. (sales tax, shipping, etc.)
In my honest opinion, his point of view also makes perfect sense.
That said, I must make it clear that I do not
consider an Ulka's piston to be a replaceable part as even though it can
be easily replaced, this should never
be needed. A coil could/would seem to be a different matter as accidental overheating (in the absence of a klixon) can make a brand new pump fail on very short notice. ie: pumping from an empty tank or anything over the two minutes continuous working time specified by the OEM.
But like you say, by the time a properly operated pump goes south, the rest of innards are most probably shot too.
Alan Frew wrote:
... internally, they don't rust, at all, ever. If your pump innards are corroded they've either been used for pumping something other than water, perhaps an attempt at aggressive descaling or they're not made by ULKA.
I fully agree and believe that it could well be the case.
It could be that dracon's water supply has had at some time an excess of chlorine or the water deposit had at some time an agressive agent of some sort. I have seen diluted chlorine bleach make small pin-holes in very good quality stainless steel cookware.
Please don't ask. =-/
Alan Frew wrote:
... found 3 states for ULKA pumps:
1) They work.
2) They half-work, pumping but not delivering real pressure ...
3) They don't work, due to scale, blockage, internal damage or coil failure.
I once had the opportunity to go through a box containing a dozen or so non-working E Series Ulka pumps belonging to a fellow that has been renting out Nemox/Napolitana type brewers for events for more than 15 years and because of that, has a large stash of parts stripped from a number of damaged and non-serviceable units. At my request, he kindly allowed me to see if I could find a couple of Ulka pump parts for myself and I can only agree with your findings.
With respect to a parts depository and associated posts, I think that it would be best to just try and catalog the few parts that the Ulka E Series have which are possible candidates for sourcing elsewhere and publish them in a short and concise 'sticky' thread.
I mean carefully measure the parts to see exactly 'what' they are.
In my opinion these would be (see photo below):
1) the infamous white plastic ball --> made from? size?
2) mushroom valve --> made from? shape? dimensions?
3) 'O' rings inside the pump --> sizes? are they standardised or special?
Original photo by Rod Schiffman
As you can see from the photo, we're talking about just six very small items, all of them easily lost when taking one of these pumps apart: a plastic ball, four 'O' rings of different sizes and a mushroom shaped rubber/silicone plug.
I am deliberately not including the pump's springs as they probably have very strict OEM specs and are specially made. I see this as a possibility but I am probably dead wrong.
In any case, I have an example of sorts to back up my idea.
I found out that the 'O' ring inside the vacuum valve inside my Cimbali Junior D/1 is size 008.
This number (008) is a AS 568A number (I have no
idea what AS 568A is) and it relates to a table of standard sizes for 'O' rings.
Looking it up, a 008 'O' ring has:
ID: ----> 3/16"
OD: ----> 5/16"
Width: --> 1/16"
With this 008 number, I was able to source a few silicone 'O' rings (ie: almost eternal) as per Paul Pratt's suggestion at http://www.espresso-restorations.com/va ... akers.html
for much less than what the same amount of original Cimbali issue replacement 'O' rings (not silicone, not eternal) would have cost me.
As always, YMMV.
Once again, many thanks to A. Frew for pitching in.
Edit: added photo, corrections and photo reference.