Gaggia Classic stripped allen screw

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by NYC_Mike »

I've done a poor job maintaining my Gaggia Classic :( although it's been running reasonably well since 2007! I've already replaced the thermal fuse twice in the last year, but now it's not passing water and it's clear all the components need a good soak.. So I am disassembling..

Unfortunately, I think I have stripped one of the allen screws trying to disassemble -- I can run to the hardware store and get a different allen key, but it's really stuck in there good.

Any advice for dislodging it?

Once I get the holding plate out I will probably proceed with the full tear down as described here but currently "stuck" on this step so any help would be appreciated!


#2: Post by SJM »

If you can pull the whole boiler out from the top of the machine, then you can sit the bottom in a pan of Cafiza to try to break the hold that the petrified coffee oils haave on the bolt.

NYC_Mike (original poster)

#3: Post by NYC_Mike (original poster) »

Thanks, I figured that's where this was headed but was hoping to find a shortcut until I have time to open the whole thing up!

Appreciate the help!


#4: Post by SJM »

Well, you could try fashioning some sort of hanging contraption that would hold a Cafiza solution up against the bottom of that plate ????

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#5: Post by Pressino »

I'd recommend using a common screw extractor. The spiral kind are the ones I've most often used. You can get a usable set from Home Depot or Harbor Freight for around 10 bucks that will work for a range of screw sizes. Here's a nice video that shows you how to use these extremely handy (when you need them) gadgets:

I've got a few different brands of them in my tool hoard. :)

NYC_Mike (original poster)

#6: Post by NYC_Mike (original poster) »

Thanks @Pressino. I'm leaning towards doing the full tear-down, even just so I can get a better angle at the holding plate. The whole boiler could use a soak and I'm pretty sure the 3 way valve needs a good cleaning too. So probably just time to bite the bullet.

Will definitely resort to the screw extractor if I'm still stuck at that point, but hopefully it doesn't come to that!
SJM wrote:Well, you could try fashioning some sort of hanging contraption that would hold a Cafiza solution up against the bottom of that plate ????
I tried giving it a good backflushing with cafiza before my last attempt.. I guess I could let it soak some more but I think it's probably time to get my hands dirtier.

Thanks again everyone! Will report back on my progress, but keep the advice coming if you've been in a similar situation.

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#7: Post by cafeIKE »

It's likely badly corroded and welded from dissimilar metals. A screw extractor may just twist the head off.

Back when I sailed, we used Tabasco sauce to 'break' aluminum and stainless welds. A specialized alternative may be available for brass[?] & stainless.

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#8: Post by stefano65 »

I like Ian suggestion, if he writes about it it is because he tried and worked,
then save the tabasco for eggs and bacon of course,
kidding apart
there are several types of extractors, some will require to drill on the screw hole a little deeper for a better grabbing some just a little pounding and they will insert in the head, the one I referring to per option 2 are squarish and not spirals style,
then of course if permitted, an heat gun might help as well
Stefano Cremonesi
Stefano's Espresso Care
Repairs & sales from Oregon.

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#9: Post by Pressino »

Well, if it's that badly corroded the OP may just have to drill it out and re-thread the boiler bolt hole (probably a bit larger) and use anew bolt (probably the next size up). Short of that and before trying the screw extractor, he could try soaking it for a few hours with B'LASTER, which is stuff that comes in a spray can and can be found at Home Depot. I've used it a few times and it can work. If not, drilling out the bolt and re-threading always works, unless the metal workpiece is completely shot. :(

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#10: Post by JRising »

Look at the distributor plate, it's so badly corroded it had 2mm+ pits in it. You would probably want to replace the distributor plate and everything that it touches. Bolts, showerscreen, showerscreen screw and possibly boiler if it too has become pitted and etched like that. Don't worry too much about damaging the distributor plate, it's not worth re-using. Hammer the crap out of that stripped bolt to ease it up for the screw-extractor.