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Thread: Is the boiler cracked on my Gaggia Classic?

  1. #1
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    Is the boiler cracked on my Gaggia Classic?

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    I have a 2002 model Gaggia Classic.

    I recently had a friend housesit who accidentally left the boiler on for around 8 hours. Totally my fault, I hadn't let him know!
    Since then the machine has had issues.
    When I switch on to pull the shot, the machine rattles for a while before slowly pushing some water through the basket whilst also leaking quite a stream of water out of the top of the group head and also around the steam wand. It also drips water into the water container. The coffee shot comes out a very watery brown and not drinkable.

    Would you say the boiler is cracked?

    Scott

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    Senior Member skidquinn's Avatar
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    Hi Scott
    It might help to work out exactly where the water is leaking from. When you say 'out of the top of the group head', does this mean out of the portafilter or somewhere else? Also around the steam wand? From the top of the steam wand? Or out of the steam wand when its closed?

    I would think its quite unlikely that the boiler is cracked - and the fact that you have water up around your steam wand (even if it is leaking) tells me the leak is somewhere else.

    Its easy to remove the top cover the Gaggia - from memory 4 screws. Take it off and have a peek in the top. It may be very obvious once you have that open.
    Remember to make sure the machine is off and not plugged in anytime you think about taking the top off..... water + electricity etc etc....

    Greg

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    Senior Member LeroyC's Avatar
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    Hey there. It's possible, but I'd say it much more likely to be a ruptured seal (or maybe a split hose). You really need to look inside to get a better idea.

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    Thanks guys.
    I took the top off and ran it for a little while. It looks like the leak is coming from around the base of the solenoid. Is this common? Any thoughts?

    Scott

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    Also - the leak is coming from the very top of the group head where it sits up against the casing. It is leaking out of another hole into the water catchment too. And then it is coming from the top of steam wand where it protrudes from the casing.

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    Senior Member LeroyC's Avatar
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    Sounds like you've got a few o-rings that need replacing. It's a 14yr old machine that may still have its original seals so they're probably quite hard and perished. Leaving the machine on for 8hrs has been too much for them to handle. The Classic is an easy machine to work on and parts are readily available if you feel like doing it yourself. Otherwise it's time to take it to your local coffee machine tech.

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    I ended up pulling it all out last night to have a closer look. The bottom of the boiler seems to be slightly warped at parts, where it sits on the group head. Water seems to come from there. Not sure this is fixable?

    The screws holding the boiler to the group head were completely impossible to remove. I could only get one out of the four. So I wasn't able to look into boiler itself.

    When I purchased it 5 years ago second hand, the boiler was cracked, so a new boiler had been put in at that point.

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    Senior Member deegee's Avatar
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    Quote Originally Posted by scottlavender View Post
    I ended up pulling it all out last night to have a closer look. The bottom of the boiler seems to be slightly warped at parts, where it sits on the group head. Water seems to come from there. Not sure this is fixable? The screws holding the boiler to the group head were completely impossible to remove. I could only get one out of the four. So I wasn't able to look into boiler itself.
    This is definitely fixable, but you will have to get those bolts out to separate the boiler from the group head. Some CRC or RP7 may help, or perhaps a Loctite product called "freeze" ( or was it "unfreeze") which I have seen, though I haven't used it.

    Once you have removed the boiler, you need a smooth flat surface and a few sheets of emery paper. Lay the emery on the flat surface and rub the base of the boiler back and forth on it, starting with a coarse grade, then medium, then fine, and your boiler will again have a smooth, flat base.

    Purists may suggest that you use a "figure 8" motion to get a perfectly even surface, but I have found that if you maintain an even pressure, and rotate the boiler in the hand from time to time, it will be flat enough.

    I have restored two Classics, and I'm currently working on a third. I have done this with all of them, mainly to remove the rough corroded surfaces, but the same technique should also work on a warped base.

    P.S. You will need a new boiler "O" ring. I managed to get them from a local bearing/seal shop, though it took a couple of phone calls to find one that stocked the high temperature version.

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    Senior Member LeroyC's Avatar
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    Great advice there from 'deegee'. The boiler o-rings are available from a few site sponsors including Coffee Parts who I've always had good dealings with. It's common for the bolts to be seized, so don't worry about that. You will need to get them out though. I had to cut one of mine off. It's worth doing so you can check out the condition of the inside of the boiler. Good luck.

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    Thanks guys. How did you cut the bolt out?? I am worried I will have to..I've started to thread one of them with the alan key as it was stuck so hard when I was trying to turn it... so it has become even more impossible to remove now :/
    Last edited by scottlavender; 13th July 2016 at 01:25 PM.

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    Quote Originally Posted by deegee View Post
    This is definitely fixable, but you will have to get those bolts out to separate the boiler from the group head. Some CRC or RP7 may help, or perhaps a Loctite product called "freeze" ( or was it "unfreeze") which I have seen, though I haven't used it.
    Is there a difference between wd40 and crc or rp7, or loctite?
    I've tried wd40.

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    I have had remarkable results with ordinary INOX on farm machinery. I let it soak in for 24 hours.

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    Senior Member deegee's Avatar
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    Quote Originally Posted by scottlavender View Post
    Is there a difference between wd40 and crc or rp7, or loctite? I've tried wd40.
    Probably little or no difference between the RP7 & and any of the WD products or clones. They are all water dispersants with a bit of lubrication. However the Loctite is supposed to work differently. When sprayed on the bolt or the nut it chills it rapidly. Presumably the contraction of the metal helps break the bond between the threads. It might work better if the boiler and the bolts were alternately heated then chilled. One trick for freeing stuck threads is to heat them with a torch then pour ice cold water on them to expand and contract the metals.

    Inox is great stuff too. I have never used it for stuck bolts, but I will be keeping it in mind in future.

    P.S. Just noticed the bit about stripping the allen key socket. I use a pair of lock-grip pliers to remove the bolts when the allen key starts to slip in the socket.

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    I managed to get a second bolt out with a high powered drill and wd-40 but the other 2 are totally stuck... no way to get them out!! There were a few of us gathered around trying out different options.

    Any thoughts? If I snap the top off the other 2 bolts what are my options then once the shafts of the bolts are stuck in the boiler?
    I've attached 2 photos. One to show the slight gap/warp where pressure and water seem to be leaking, and the second of the side where the bolts are still stuck.
    Attached Images Attached Images

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    Senior Member deegee's Avatar
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    Well, there is one other possibilty I would try. First you need a solid piece of hard wood to sit the group head on. It needs to be hard and thick and solid enough to have very little give. With a large drift and a heavy hammer strike the top of the bolts with several sharp, heavy blows. This may loosen the bond between the male/female threads enough to be able to screw them out.

    If you snap just the heads off the bolts, you should be able to lift the boiler off, and there will still be some of the shaft protuding fom the grouphead which you may be able to get a grip on. Do you have lock-jaw pliers or a small pipe wrench ?. Have you tried the alternate hot/cold method ?.

    If you snap them of flush with the grouphead, the only solution would be to drill them out. Difficult to get right even with a drill press and vyce, even more difficult to keep straight & centered with a handheld drill.
    MattyRay likes this.

  16. #16
    Senior Member LeroyC's Avatar
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    The hole where the bolt passes through the boiler isn't threaded from memory, but this is the part that actually gets seized. It's an unfortunate by-product of the two metals present. If you can cut the head off the bolt you'll be able to pull the boiler off. At this point the remainder of the bolt should come out of the group head easily as I don't think the thread itself will be seized. You'll just need some pliers to turn it, but it might even turn by hand.

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    Ok so I finally got the boiler off the group head!! It was HARD work! I ended up getting a cobalt drill bit to drill through the remaining two bolts. They were clinging on VERY tightly! Unfortunately it did some slight damage around the holes of the boiler and of the group head as I had to have the drill at a slight angle... essentially making two of the holes a little wider at some points. Has this ruined it completely?

    I will be using some emery paper on the bottom of the the sander and top of group head. There's a layer of filth within the boiler - and some slight deposit build up which I will need to descale and scrub.

    Any other advice? (if it's not ruined already??)

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    Do the replacement bolts need to be any particular material? I found some the right size as glavanised zinc, but worried this might react with aluminium boiler?

  19. #19
    Senior Member deegee's Avatar
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    Quote Originally Posted by scottlavender View Post
    Unfortunately it did some slight damage around the holes of the boiler and of the group head as I had to have the drill at a slight angle... essentially making two of the holes a little wider at some points. Has this ruined it completely? I will be using some emery paper on the bottom of the the sander and top of group head. Any other advice? (if it's not ruined already??)
    If it is only the holes through the boiler flange that have been enlarged, and the threads in the group are OK, then it should be fine.

    I would advise against sanding the top of the group unless it is badly warped. They are usually chrome plated brass and you don't want to remove the chrome and expose the brass. It would be much more prone to corrosion than chrome. Try cleaning it with a heavy duty scourer or even fine steel wool, but not emery.

    I used stainless steel bolts on mine, because they are less likely to corrode. You don't have to use Allen-head cap screws like the originals, I used hex-head SS bolts and they worked fine. Before I screwed them in, I greased them lightly with high temperature bearing grease.



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