# E-61 group mystery



## soundklinik (May 31, 2013)

....is that I have almost all the time a small amount of *pressure* that stays in the Porta-Filter, after I made a shot.

Odd is, that when I turn on the *Isomac TEA 2*, and do a backflush, (when machine is cold), the water shoots out perfectly. Whoosh

The hotter the machine gets the more pressure stays...

I took apart the lower part of E-61, sanded the little pistons with 300grit W/D and still it persists...

Which part exactly is responsible for the release of pressure? the 2 little "pistons" pushed with springs are not exactly a "tight fit", so I am puzzled as to what causes this slow release...

Appreciate any tips...THANKS


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## El carajillo (Mar 16, 2013)

Have you checked the cam? Does it show signs of heavy wear ? If it does it may not be depressing the valve (s) sufficiently. Although this would not account for difference between hot and cold.







Does the machine need descaling ? Removing top plug from E 61 head may show signs of scale.


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## DavecUK (Aug 6, 2013)

There is either wear in the valve pins where they contact the cam (on the lever), or they have been replaced and the new pins are slightly shorter...as it heats up, everything expands and the group venting although not as powerful seems OK. read the links below, to find out how your E61 works.

http://coffeetime.wikidot.com/search:site/q/e61


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## bronc (Dec 10, 2012)

I wouldn't recommend sanding anything that is not cheap to replace. Have you ever performed a chemical backflush, i.e. with Puly Caff? Maybe gunk has accumulated and it prevents from full pressure release.


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## soundklinik (May 31, 2013)

Thank you all for the tips...









Yes, the cam has a slight wear...after all it pushes on all those springs...

Which confirms the tip from Dave that the expansion will cause a shorter travel...

By sanding I meant polishing the parts with 300grit wet and dry....

I dismantled the group several times, I guess I was looking for the pressure release problem in a wrong place...

That would mean I need a new cam? The rest of the parts are clean and in good condition, I got a rebuilt kit a year ago, washers, seals, springs, etc...no hardware parts like cams etc...


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## El carajillo (Mar 16, 2013)

If the cam has / does show signs of wear , also check the ends of the valve stems that sit on the cam. If these show scoring, burrs or wearing slightly concave you should replace the cam and the valve pins. Also make sure the valve seats are clean when you reassemble ( where the rubber seals sit).


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## DavecUK (Aug 6, 2013)

Sorry I meant when it heats up, it seems just OK as everything expands, but, yes it is down to wear...I shall correct that post.


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## soundklinik (May 31, 2013)

Sorry, I had to bump this thread, because I don't understand why the slight wear on the cam would influence the "lack of release" to such degree.

When the machine is COLD, water shoots out...the more it warms up, the slower the release...it almost feels like something grips the valves and prevents them from traveling UP/DOWN..

If I unscrewed the screw in top valve a bit (small rectangular thing that gets pushed with cam FIRST) inside the E-61, wouldn't that make the compensation for wear?

Don't misunderstand, I am not arguing, I am just wondering if it's not something else...[bUT WHAT?] in the chain of the valves being released...and it's bugging me that I can't figure it out:waiting:

To my knowledge, there are no valves in the group that also seal "around" them, with their sides? All have a rubber seal on top, held with a tiny screw...

Far fetched, but if one of the small pistons was out of round or damaged, could it start to grip as the group head heats up? Grease stuck in there?

Thanks for your ideas...

PS anyone knows which kit for E-61 is compatible with ISOMAC TEA 2? That is from BB?

https://www.bellabarista.co.uk/espresso-parts/coffee-machine-parts/e61-group-head.html


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## El carajillo (Mar 16, 2013)

It is the lower/ bottom valve that releases, check the underside of the cam, is there much wear ? Inspect the lower cam face and the lower valve stem end. In some E 61's there is a small cupped washer with small holes in, check it is fitted correctly (if this applies). and that the holes are clear.


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## soundklinik (May 31, 2013)

El carajillo said:


> It is the lower/ bottom valve that releases, check the underside of the cam, is there much wear ? Inspect the lower cam face and the lower valve stem end. In some E 61's there is a small cupped washer with small holes in, check it is fitted correctly (if this applies). and that the holes are clear.


Thanks El carajillo, will check that...There is some wear on the cam I saw it last time...I will have to double check all the other pieces

I do have the one with the small washer with holes [all the way on the bottom].. and guess what, the first time I took it apart I assembled it upside down,







LOL

Thanks for the tip


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