Gaggia Spring Lever project - Page 6

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EthanL (original poster)
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#51: Post by EthanL (original poster) »

Paul_Pratt wrote:Yes exactly as that Hagerty video. For the studs that are flush, first weld a washer onto the stud, it makes it easier to penetrate the stud. Then a nut on top of the washer.
Hi Paul, do you have experience with this group head? Where should I start to disassembly it, is there a better way to remove the sleeve B?


EthanL (original poster)
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#52: Post by EthanL (original poster) »

Cooked the group head outer piece with Urnex, most coffee gunk are gone, and found some damage in the group head gasket groove, I guess it's from previous restoration when somebody tried really hard to remove the gasket, must have done it with wrong tools sadly...


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IamOiman
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#53: Post by IamOiman »

A sleeve in my group was bent similarly to yours but facing towards the center. I took a dolly hammer and lightly tapped it back into place without issue. You could try that with yours but it would be awkward to angle the hammer correctly and you could strike something you do not intend. You could also take a pair of needlenose pliers to at least bend the sleeve into the right direction incrementally, but you would need to adjust the sleeve once you do that and probably clean up any potential scratches made from gripping the sleeve. Overall you want the piston to be able to slide in and out without touching that sleeve. Technically you could leave it as is but me personally I would try to fix it up a bit.
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EthanL (original poster)
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#54: Post by EthanL (original poster) replying to IamOiman »

I remember I was in a situation I had to make the opening of an aluminum cup back into round, and it was a disaster...

I may leave it as it is now just afraid it be made worse and see if any leakage happens at the group head when everything is put back together! Thanks Ryan for your thorough how-to, may have to do it eventually :)

EthanL (original poster)
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#55: Post by EthanL (original poster) »

People in the machine shop think there is not enough material for drilling out the snapped bolts and remaking the threads, so I'm gonna try my luck do some bolt extraction, have to source a new boiler in case of failure. And a claw puller worked great to take the metal sleeve off the piston :)

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JIMBOJOHN55
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#56: Post by JIMBOJOHN55 »

Hi Just finished one of these over in the UK - let me know if you want any info on it - cheers Jim
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EthanL (original poster)
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#57: Post by EthanL (original poster) replying to JIMBOJOHN55 »

Thanks, waiting for the ordered parts to come and slowly setting up a small machine shop at the moment, hopefully some progress after new year.

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drgary
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#58: Post by drgary »

EthanL wrote:People in the machine shop think there is not enough material for drilling out the snapped bolts and remaking the threads, so I'm gonna try my luck do some bolt extraction, have to source a new boiler in case of failure. And a claw puller worked great to take the metal sleeve off the piston :)
I'm interested to see this and look forward to Paul's response. I dealt with snapped bolts on my Conti Prestina restoration. A friend helped me shear off the bolts and taught me to drill them out starting with a small bit centered in the middle of the bolt material and moving to larger bits. Several enlargements later and my drill bit reached the edge of where the bolt met the boiler wall. I then retapped. This process did not require inserting helicoils. Since this method preserves the material that is already there, I don't know why it can't be used, and it avoids replacing the boiler.

Perhaps it isn't recommended because there's a possibility of drilling slightly off center? My Prestina has been working well for years after doing this.

Conti Prestina Espresso Machine Restoration 101 (Completed and Indexed)
Gary
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jwCrema
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#59: Post by jwCrema »

I've dealt with this on old engines. I am interested in what Paul says too - my view is that this isn't a matter of being recommended or not, it's all about the skill of the machinist.

You must to hit dead center with the first drill bit hitting the old bolt to create a perpendicular hole. This means dead center on both ends of the bolt. A drill press with a high grade chuck along with a vice and some serious patience would be required.

I am seriously impressed you two pulled it off on the Conti - this is not accomplished by children or the ham-fisted.

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drgary
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#60: Post by drgary »

Thanks. I drilled it out with a hand drill and just went slowly, using Jay's instruction on how to prop up the drill with my other hand so it was vertical. Jay is very experienced, obviously. I was brand new to this. Once the bolts had been sheared off, they weren't very thick, so absolute vertical wasn't necessary beyond eyeballing it. If the center hole wasn't completely centered, I compensated with the next bit size to re-center.
Gary
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