# Changing seals on an L1



## 4085 (Nov 23, 2012)

I have not kept up to speed with this topic. This morning when making a shot half way through the pf handle and shower screen and seal forced themselves off. The seal seems quite hard so could do with a change. It looks quite thin so am presuming they are 8 mm and not 8.5 mm. What in others opinions, are the right kits to buy and from where. I seem to recall Cafelat and then also that Londinium have changed theres over. I might as well buy the piston kit as well in preparation for Patricks next visit!


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## 4085 (Nov 23, 2012)

AM I right in thinking that the piston seals from Londinium are a new super dooper type, but nothing has changed with the pf seal?


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## 4515 (Jan 30, 2013)

Ive just received a set of Londinium seals and they are black round things - they look just like the last set I bought from Reiss.

Ive recently fitted the cafelat seals but the bite point was way too high on my machine so I installed a workaround (4 wraps of PTFE in the grooves for the seals). This isn't ideal but did improve the grab position.

I'll be installing the Londinium seals this weekend


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## arellim (May 9, 2016)

As a result of extensive reading I went for the Londinium [new] ones

I noted that Cafelat are amendment that their seals are the proper ones and any high grabbing is a fault of the machine.

I wish I'd got a couple of extra PF seals too when ordering from Londinium, but you live and learn.


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## NickR (Jul 1, 2011)

working dog said:


> Ive just received a set of Londinium seals and they are black round things - they look just like the last set I bought from Reiss.
> 
> Ive recently fitted the cafelat seals but the bite point was way too high on my machine so I installed a workaround (4 wraps of PTFE in the grooves for the seals). This isn't ideal but did improve the grab position.
> 
> I'll be installing the Londinium seals this weekend


I replaced my seals after about a year with pre "precision seals" from Londinium. The improvement was huge. I re grease about every 6 months, but these seals still seem to be going strong after about 2 years. I get an absolute max shot of about 40g. I'd be really interested to know if the precision seals take this any higher.


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## 4085 (Nov 23, 2012)

Thanks all. Have bought a couple of sets from Londinium


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## arellim (May 9, 2016)

NickR said:


> I replaced my seals after about a year with pre "precision seals" from Londinium. The improvement was huge. I re grease about every 6 months, but these seals still seem to be going strong after about 2 years. I get an absolute max shot of about 40g. I'd be really interested to know if the precision seals take this any higher.


I have the new seals. I can weigh a few shots this evening. I reckon i could get 65g plus but it's only a guess.


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## Snakehips (Jun 2, 2015)

NickR said:


> I replaced my seals after about a year with pre "precision seals" from Londinium. The improvement was huge. I re grease about every 6 months, but these seals still seem to be going strong after about 2 years. I get an absolute max shot of about 40g. I'd be really interested to know if the precision seals take this any higher.


It's all down to minor changes in geometry but In my experience, the now standard Londinium piston seals are far, far, better than the old ones. Still round and black though as @working dog says.... which is comforting.

In the absence of any Fellini type jiggery-pokery, the max volume available from a tank fed original L1 will be about 40ml. Inlet / pre-infusion is at boiler pressure of 1.4bar which can only compress / displace 40ml or so of the air that originally occupies the cylinder.

You can get up to about 60ml max from an L-R if the PI pressure, which is pump driven, is at 3.5bar.


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## Thecatlinux (Mar 10, 2014)

I think the life of group seals will be dependant on how long the machine is on and also whether you leave the portafilter in when idle or off.

CC kindly sent me one last week and it wasn't till you compared the old one with the new one you could realise how hard these go , I am currently going through 2 a year but it's probably going to be a bit more from now on .

i think 8.5mm might be a bit tight .


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## johnealey (May 19, 2014)

Hi All

Londinium Advanced piston seals Vs Cafelat:

Last weekend I decided it was time to swap out the piston seals on the L2. I had one set of the newer advanced Londinium seals and two sets of cafelats. I could have taken the easy route and fitted both the same but given there has been some discussion about differences between the two suppliers.

The existing seals were ok, only the bottom ones being slight harder, no cracks, not brittle. Quick view of Patricks very useful Piston seal change done at the last Rave day.

Quick removal of both sets with a scalpel and then fit the Londinium set first using the two bits of wire idea from the video to get the topmost and second seals in, boy these are tight. Equal amounts of Loxeal measured out for each group, teeny amounts really. Londinium piston seals and bore greased with a thin film, back into bore, gentle tighten, operate lever 3 times and remove the excess.

Onto the 2nd piston this one with the cafelat seals. Much softer and having got the wires ready as per piston 1, not required, definitely more flexible and a lot easier to fit (easier on the fingers too!), equal amount of loxeal applied as per piston 1, refit, operate lever and remove excess as previously.

New set of Cafelat group seals also fitted, appear to be slightly "taller" than the std londinium's but again softer, locking in more at the 7 o'clock position comfortably having used an empty naked portafilter handle round to the 3 o'clock position then fit basket and around to 5 o'clock so as to ensure properly seated.

In Operation: On my machine both levers pre seal change used to take up at the same point and post change they both take up at the exact same point, good news noting this is a plumbed in L2 so take up is lower than on an tank fed L1 for example. Yesterday evening the Londinium sealed lever started to judder a little which was cured with a little more loxeal ( if there is anything to be learnt from this one incident it may be to add a little more loxeal to the seal face and let the bore scrape it off for collection prior to refitting shower screen)

Hope the above of help in any decisions re seals for pistons / group and will update in a few months time with any further info relating to use

John


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## Thecatlinux (Mar 10, 2014)

Well fitting the different seals side by side in your L2 is going to be a perfect bench test for comparing the two different types of seals , you will have to keep count of each lever pull though .


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## johnealey (May 19, 2014)

only ever make two at a time (or multiples thereof).

If Sarah doesn't want one I have to "suffer" and have the second...

John


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## 4085 (Nov 23, 2012)

I thought I would change the pf seal today. Surprisingly, the shower screen and seal simply pulled off the group head without an issue. I have looked at the new seals and they seem to be uniform with no markings, so my question is, does it matter which way up you fit them?


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## Snakehips (Jun 2, 2015)

dfk41 said:


> I thought I would change the pf seal today. Surprisingly, the shower screen and seal simply pulled off the group head without an issue. I have looked at the new seals and they seem to be uniform with no markings, so my question is, does it matter which way up you fit them?


I have always found the Londinium shower screen and seal come off very easily.

I reckon you could get away with fitting the seal either way up but there are small radii on one of the seal faces and I always fit with radius uppermost as in leading into the group.

Visually, the rad is maybe a tad hard to see but you can actually feel the difference with your fingertips. On a new seal there is a sharp feel to the lower edges and the lower face actually feels a tad concave.

Hope that helps.


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## 4085 (Nov 23, 2012)

Snakehips said:


> I have always found the Londinium shower screen and seal come off very easily.
> 
> I reckon you could get away with fitting the seal either way up but there are small radii on one of the seal faces and I always fit with radius uppermost as in leading into the group.
> 
> ...


Many ta's


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