ACS Vesuvius Evo Leva

danielpugh

Hi all,

Previous problem (leaking from back of group) back again, but now a little worse. Have emailed Paolo, but thought worth asking if anything else to try. One thought was the upper/higher gasket. I don’t seem to have a spare of that but maybe another thing to try?

LMSC

danielpugh One thought was the upper/higher gasket. I don’t seem to have a spare of that but maybe another thing to try?

Sorry to hear. Paolo is the best person to advise now.

Changing all the gasket is definitely the next course of action, IMO. Too soon to change them.

I am not sure lubricating as per @Systemic video will help.

SebH

As its super hard to search in Threads with this forum software (or I did not find the button):

Is there any consensus on optimal PID settings? The default settings overshot by 2 degree on my EVO and I now raised B to 50 (following https://onedrive.live.com/view.aspx?resid=889B290848E68B67!43085&authkey=!APmfRj0iIP-QcQs).

This seems to fix the overshooting and the heating cycle reduced. Did not notice any side effects.

LMSC

SebH I have thrown everything at it by taking the P as low as possible, I to Zero and D higher - not all of them at the same time but in some combinations. It only reduced. Mine still constantly overshoots by 1.5C.

You may try the following:

P=1.2 I=0.02 D=12 PID setting (B) =5 or what ever you have now
P = 0.5, I = 0, D = 22, B = 50 - My current set up. Still 1.5C overshoot (excluding the initial 30 mins).

Hope it helps.

danielpugh

@LMSC yep used molykote 111 and followed video by @Systemic Replaced the larger gasket (as advised by Paolo), and the teflon ring. Didn’t have a spare for the smaller gasket. Not sure where to get the smaller gasket (or whether swapping will make any difference).

[Edit]. One thing that did occur - is there supposed to be a gasket for the two parts of the group? (I.e. between the piston part that lifts off and the part remaining attached to the machine). There is a groove surrounding the bore that looks like it could take something, but nothing there?

LMSC

danielpugh

danielpugh One thing that did occur - is there supposed to be a gasket for the two parts of the group? (I.e. between the piston part that lifts off and the part remaining attached to the machine). There is a groove surrounding the bore that looks like it could take something, but nothing there?

There is a gasket between the outer part of the piston and the group. Is this the one you are indicating? There is a black-coloured gasket.

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DavecUK

danielpugh the bore is a stainless steel wet liner with O rings top and bottom and pushed in. Please make a good close up photo of what you are describing.

I said I was surprised it was the piston seal ..it could be leaking from this area?

danielpugh

@LMSC - I mean between the top and bottom of the group - i.e. top being lifted off after undoing the 4 nuts, and bottom containing the shower screen and hole. The leak I have is at the back between the two parts, so just wondering if I am missing a gasket between the two parts. From the exploded parts diagram I have I think not, but just checking.

[Edit] by bore I meant the hole in the lower part of the group with the shower/circlip in.

LMSC

danielpugh No. I don’t see anything.

LMSC

Having opened the group, I cleaned the piston, the bore and lightly greased them.

danielpugh

@LMSC - great that’s one Less think to worry about. Paolo has just replied suggesting tightening the piston from underneath (?). Need some circlip pliers and will try next…

LMSC

danielpugh How do intend tightening the piston from the bottom of the group? You can’t, can you? I believe you need to take the piston out, tighten the bolts and the piston head a bit. You have Norvin’s tool, right ?

danielpugh

@LMSC I think he meant - remove circlip and screen then use the tool from underneath. Presumably so the gasket is compressed and pushes outward to remove any gap.

In the interests of speed I just took the whole thing off, tightened the piston and replaced. I’ll get circlip pliers in parallel as need some and can’t find my old ones.

LMSC

danielpugh Let’s know how it goes. Get some GU10 stainless steel clips or use the single basket portafilter pins.

danielpugh

@LMSC - thanks - yes have a bag of GU10. Just need the pliers…

DavecUK

The piston must be tight enough to make the seal bulge slightly, but not too tight. This is so it makes a good seal. Once there is good pressure of water that helps push the seal tighter against the bore.

danielpugh

DavecUK - I think it arrived overly tight - needed some effort to loosen. I probably did back up too loose - 4 shots fine, so fingers crossed… thanks!

LMSC

danielpugh Good job. well done mate!

Norvin

danielpugh DavecUK - I think it arrived overly tight - needed some effort to loosen. I probably did back up too loose - 4 shots fine, so fingers crossed… thanks!

After devising and making a tool to fit the piston I was almost disappointed to find that the piston on my Evo wasn’t screwed on very tightly, although it may get harder to unscrew with age. Interesting to see that there is a variation in tightness between new machines. Did you find the tool useful?

DavecUK

danielpugh I think it arrived overly tight - needed some effort to loosen. I probably did back up too loose - 4 shots fine, so fingers crossed… thanks!

That’s great, because if that hadn’t worked the only other place would have been the O rings….which is quite rare, even on a very very old group.

LMSC

Norvin The same thing here. The piston head wasn’t super tight in our case; we didn’t struggle to remove it. It came off easily. But, we can’t dismiss your tool as not useful. It does make the job easier and we are also comfortable in the knowledge of its’ future value! 😊

danielpugh

Norvin Hi, yes very useful. Without it I would have struggled to undo. It was very tight originally.

danielpugh

DavecUK unfortunately it’s still leaking. Are the o-rings the one just below the spring?

Trying to think out - it must be getting past both the gasket and the upper o-ring in order to come out of the top.

At a loss at this point as there isn’t much to do differently or swap?

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