# Backflush de-lubricates? (Sorry should have been in Technical)



## Beemer (Jun 19, 2012)

I bought and have twice used Pulypowder to backflush my E61 grouphead

http://www.thomsonscoffee.com/pulypowder-backflushing-grouphead.html

I was surprised to note that after the second flush 10 days after the first, the pump lever movement had a distinct "dry squeak" both on and off. It was as if there was no lubricant left between the lever cam and the plunger. I had assumed that there would be seals in place such that flushing agent would not get access to lubricated surfaces.

It won't be a hard job to re-lubricate if it has been removed although I will need to buy the food type of grease. Before I strip the group has anyone experienced this squeaking?


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## vintagecigarman (Aug 10, 2009)

E-61s don't take kindly to too-frequent flushing with detergent, and the squeak indicates exactly what you think - the lubricant is breaking down. The good news is, that if you start using your machine again the coffee oils themselves act as a lubricant and the squeak will soon disappear.

Regular - daily - water alone backflushing will keep the head satisfactorily clean. I only do a detergent backflush once every three months.

I doubt that at this stage you'll need to re-lube the head.

I soak my portafilter & basket in PulyCaff once a week, and when I do that I pull out the shower screen and soak that as well, using a bit of the detergent to clean the head behind the shower screen.

Works for me, though othre may have a different regime.


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## Beemer (Jun 19, 2012)

You were correct in that the squeaking has now stopped. I'll go easy on the Pulypowder.

thanks


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## Spazbarista (Dec 6, 2011)

I suspect this stuff about detergent flushing out the lubricant might be yet another example of a myth spread via what people read on the Internet and here is why..

I find that the squeaking stops as soon as I start flushing out the detergent with clean water. This leads me to think that the squeakiness isn't caused by the sudden disappearance of the lubricant but in fact is a result of the grittiness of the detergent. After all, it doesn't actually dissolve immediately, and it is fine enough to pass through the shower screen as a suspension in water. As you flush out the detergent with water the gritty residue is washed out resulting in a smooth lever action.

I am equally suspicious of the belief that food-grade lubricants would be able to resist the constant high temperatures and flushing through of hot liquids. Coffee oils may well go some way towards lubricating the cams and pins but of course the presence of those oils is the precise reason for using detergent in the first place.


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## vintagecigarman (Aug 10, 2009)

Dow Corning 111 has an operating range between -40 and 200 Celsius, so should be able to handle the heat. If it's applied to a dry surface it tends to stay put unless it comes up against a strong emulsifier - like PulyCaff.

Myth or not, there's enough horror photos on enough different sites, to make me cautious of over-use of detergent.


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## lookseehear (Jul 16, 2010)

Dow Corning is great - its called molykote in the UK though. I use it when I clean my lever. Food safe and stable to high temperatures.

Sent from my Nexus 7 using Tapatalk 2


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## vintagecigarman (Aug 10, 2009)

Is Molykote identical to DC111? I have bought DV from the States as I couldn't source it over here - but a tub will last me a lifetime! I use it on the adjuster collar threads on the Mazzer as well.

Sent via Tapatalk


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## Spazbarista (Dec 6, 2011)

vintagecigarman said:


> Dow Corning 111 has an operating range between -40 and 200 Celsius, so should be able to handle the heat. If it's applied to a dry surface it tends to stay put unless it comes up against a strong emulsifier - like PulyCaff.
> 
> Myth or not, there's enough horror photos on enough different sites, to make me cautious of over-use of detergent.


I may of course come to eat my words, but there is a counter argument. Those pins and cams are cheap replaceable parts. Is there any logic in having a high end machine, but producing inferior coffee through not keeping it clean? I guess the ideal solution would be to frequently chemically clean and relube.


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## lookseehear (Jul 16, 2010)

vintagecigarman said:


> Is Molykote identical to DC111? I have bought DV from the States as I couldn't source it over here - but a tub will last me a lifetime! I use it on the adjuster collar threads on the Mazzer as well.
> 
> Sent via Tapatalk


I'm pretty sure it is - can't remember where I read it though but it was when I was trying to source Dow corning in the UK. I bought mine from eBay ages ago but coffee hit now stock it.

Sent from my Nexus 7 using Tapatalk 2


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## Spazbarista (Dec 6, 2011)

vintagecigarman said:


> Is Molykote identical to DC111?


Yes it is.

Available at reasonable cost here:

http://item.mobileweb.ebay.co.uk/viewitem?itemId=180923107061&index=3&nav=SEARCH&nid=30081274922

Out of sheer curiousity I'll have a little experiment to see how many backflushes result in removal of the grease.


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## Spazbarista (Dec 6, 2011)

vintagecigarman said:


> Is Molykote identical to DC111? I have bought DV from the States as I couldn't source it over here - but a tub will last me a lifetime! I use it on the adjuster collar threads on the Mazzer as well.


Well, I'm not going to eat my words just yet....but I have put them back in my mouth and am gently chewing them.

I've just relubed the lever. No sign at all of any lube when I dismantled. Once lubed it all feels beautifully smooth, enough to make me think it is worth relubing, regardless of whether it is chemical backflush or just plain use that flushes out the lube. I am going to have another look in a couple of weeks, without any chem use and see what lube remains. Then try backflushing and compare. I'll let you know what I find, but in the meantime I think your advice to relube is wise.


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## Beemer (Jun 19, 2012)

Expobarista said:


> Yes it is.
> 
> Available at reasonable cost here:
> 
> ...


I've been away on holiday since my OP but can report that the squeaking is much less than immediately after the flush. I have now seen breakdown images of the E61 and have no concern about re-lubricating if the bean oil fails to restore the lever slickness.

I find it intriguing that, we here, are sensitive to the minute changes in our equipment and technique. This is becoming a very interesting hobby for me!


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## Spazbarista (Dec 6, 2011)

Ok, I now have some evidence to believe that the following is true:



Expobarista said:


> I find that the squeaking stops as soon as I start flushing out the detergent with clean water. This leads me to think that the squeakiness isn't caused by the sudden disappearance of the lubricant but in fact is a result of the grittiness of the detergent. After all, it doesn't actually dissolve immediately, and it is fine enough to pass through the shower screen as a suspension in water. As you flush out the detergent with water the gritty residue is washed out resulting in a smooth lever action.


Just did a chemical clean, having not done one since previous post on this thread. Loads of crap came out. Usual notchy squeaky lever, which eased up once I'd flushed all the detergent out. Opened up side of group head to discover that parts were still adequately lubed from previous service.

From this, I conclude that my theory above is correct and that also Molykote can survive at least one backflush (allowing detergent to soak for about ten minutes).

I'm with VCM in that the thing needs lubing, but I also think detergent backflushing is necessary. I think ill be doing a twice monthly chem backflush, and a relube either every time or every other time.

The relube took 5 minutes.


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