# E61 group head service



## ArisP (Dec 17, 2019)

Ok folks, took the plunge and ordered a generic e61 group service kit from BB. It arrived yesterday, and today spent a few hours taking the group apart and replacing washers and seals.

What I found is:

For a 16 year old machine, the group is in pretty good shape!

All of the seals and washers needed replacing.

The cams and mushroom, even though are slightly worn, don't appear to need replacement.

Finally, this is indeed a "generic " kit; in my case, only the seals and washers could be used, and even those with a bit of risk as they where thinner. The springs supplied are all either shorter or longer or have completely different "thread spacing ", being the distance between the coil revolutions. Since my springs appear to be in good condition and stiff enough, I decided not to risk putting in different spring lengths.

Below are a few pics I took for everyone's amusement. If you see a glaring mistake, feel free to point it out. Have to break these into multiple posts due to size limitations.

I tested the machine after putting it back together, using a blind portafilter, both while cold and again after reaching proper temperature, and it seems to work fine without any leaks.


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## ArisP (Dec 17, 2019)




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## ArisP (Dec 17, 2019)




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## ArisP (Dec 17, 2019)




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## ArisP (Dec 17, 2019)




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## DavecUK (Aug 6, 2013)

Just remember over many years spring lengths change, they lose elasticity etc...


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## El carajillo (Mar 16, 2013)

Firstly, congratulations on tackling the job .

As you pointed out , for it's age it looked to be in decent condition. The cam and valve stem wear does not look excessive, nothing that a good clean and lube will not put right.

The "O" ring for the mushroom does look rather thin but as it does not move providing you could feel it compressing as you reinstalled it should be OK.

Reference the springs they do become compressed and tired.To compare springs count the number of coils, not the space between the coils. The new ones will feel considerably stronger and be longer overall


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## ArisP (Dec 17, 2019)

DavecUK said:


> Just remember over many years spring lengths change, they lose elasticity etc...





El carajillo said:


> Firstly, congratulations on tackling the job .
> 
> As you pointed out , for it's age it looked to be in decent condition. The cam and valve stem wear does not look excessive, nothing that a good clean and lube will not put right.
> 
> ...


 Thanks gents,

Indeed, I was expecting that overall there would be a small length difference between the old and new springs, but after placing them next to each other, the difference seemed large.

Also agree that the total number of coils is more accurate rather than the spacing. Perhaps I should try changing them anyway and see what happens?

Finally, what's your opinion on removing the top and bottom parts of the group without removing the side (cam), it is a pain to align...am I just looking for trouble?


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## El carajillo (Mar 16, 2013)

There will be no problem removing the top and bottom of the group as the cam assembly is held in place at both ends .


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## ArisP (Dec 17, 2019)

Thanks, might try it then, with the lever at the mid position of course.


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## DavecUK (Aug 6, 2013)

Oh, just a thought, either get some jaw protectors for that wrench, or at least tape up the jaws


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## ArisP (Dec 17, 2019)

DavecUK said:


> Oh, just a thought, either get some jaw protectors for that wrench, or at least tape up the jaws


 Yup, on my to do list!


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## ArisP (Dec 17, 2019)

Ok, thought I'd try again. In the photo below, you can see the "original " springs (they might not be, but where in the machine when I got it), and to the left the springs that came from BB. We could argue that the bottom one might work, but the rest are already shorter and a lot less stiff.

To be crystal clear, this is not BB's fault by any means. They just don't seem to be the right fit for my machine.


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## ArisP (Dec 17, 2019)

So to wrap this up, thought I'd give the new springs a try regardless of obvious differences in length, and as you might imagine, they seem to work fine (with the machine cold, will try pressure again once it reaches full temperature)

Another good thing that came out of me tinkering, is that while pressure testing I saw a single drop of water rolling down the group. I thought I simply had to screw the top part a bit tighter, which I did, and then gave it another go. Another single drop of water came rolling down...

To cut a long story short, the alen screw (that you would remove to install Eric's thermometer) was not even finger tight... how did we manage not to get a face full of steam and hot water I don't know. Trying very hard not to read anything into this....


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## DavecUK (Aug 6, 2013)

The preinfusion spring you really want opening at 4 bar, ideally even less. So being thinner and with less tension isn't a problem. The top valve is forced closed even tighter by pressure, so the spring there is simply to keep it sealed and you work against it when lifting the lever. So arguably slightly less aggressive means less wear on the cam followers.

It is a generic kit designed to work in a wide range of groups, as you may well know there are a number of E61 group manufacturers and they all use slightly different spec parts.

I hoped you checked those cam follower pins are the correct profile on top and have no wear....I would be surprised at no wear after all this time, unless the machine was either well maintained, or only lightly used....of course they could be replacements and the group may well have been overhauled some years ago....

You will see close-ups of those pins and what they should look like at this link.

http://coffeetimex.wikidot.com/e61-group-servicing


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