Seacoffee wrote:Hi Paul I am currently restoring a gaggia internazionale single group, can you tell me where you got the new spring?

http://www.coffeeparts.com.au/gaggia/522412
$31

John

Thanks John,

Much appreciated.

Paul_Pratt wrote:Thanks for the tips.

I have run into a small problem. The temperature of the water is great, but I am still a bit low on extraction pressure. Even with the new spring, which I thought was working, I am getting 6-7 bars maximum. As such the coffee is a bit off.

I imagine that the compression by the group seals on the piston acted upon by the large compression nut must increase the friction on the piston and also effect the max bars. Maybe need to have enough compression to stop leaks but not too much to significantly increase the friction. I haven't yet got to that stage so merely conjecture on my part.

jmc wrote:Paul, My understanding is that old spring levers never reached 9 bar even when new. The range you have quoted is about normal. What I do is grind finer and tamp with no weight, merely to level off the top. This has worked on a number of machines now, including ones with the same heads as your Gaggia, and I think it will work with any of these machines. Drip, drip pours don't tend to work very well either.

John

John you are dead right, 9 bars has been touted as the be all and end all but that was never really talking about at the coffee, merely somewhere along the water lines coming off the pump. The reality is the pressure is a bar or so lower if measured a the coffee using a Greg Scace device.

I've had a few levers that were close to 8-9 bars but never any as low as 6.

Thanks for all the suggestions to everyone. The seals are working very well, sadly though I have not had any time to experiment for myself as my office move is taking up all my time. Today though to prove a point I gave the lever a strong helping hand on the upstroke (to add pressure) and I got an awesome looking and tasting shot, full of mottling and a dark crema that I don't get normally.

After my office move I shall investigate further.

As I said before, if these machines were easy then we would be missing out of half the fun and learning as much as we can about how they work.

Follow-on discussion split to Gaggia Orione restoration redux.