I'm struggling a bit here. I have 2 Caravels and an Export, and each of them has slight issues. Anyway, the Export one is the one I need to fix first really.

So, I've had the Export from new for about 2 years, and I've never changed any seals etc. It's been working OK until today, when something strange has started to happen.

Usually, I bring the lever down until it's almost parallel to the worktop before I put the portafilter in. This is because I know I can get the lever this far before it starts to let water into the piston chamber. I tried to do this this morning, and before I got to the parallel point, water started to come out, which has never happened before. I continued to the parallel point, and the water stopped coming out. I then let the lever come back up, and at no point does more water come out. I repeated this process, and again there is a point between vertical and parallel to the worktop where the hot water starts to come out. It doesn't come out at the same point in the release of the lever.

I should add that if I quickly move the lever from its vertical position to the parallel position, I can avoid too much water coming out, but clearly something is wrong.

Can anyone give me some advice about what may have happened to the machine? Perhaps something to do with the seals?

Sounds like a compromised seal. Taking the group apart and re-assembling it is...not fun. I've done it 3 or 4 times on my Export and have sort of worked out a system, but the design of the group and the strong spring makes it pretty challenging to get back together.

Unfortunately it sounds like you will have to undertake this. You can search this forum and find several posts about servicing the Export's group, with tips about how to remove and then re-install the piston.

Certainly listen to Greg as he has way more experience than me, but I'm not understanding what the problem is. If water is coming out, can you still make espresso?

My Export is out of service temporarily as I removed the PF gasket to try to remove the shower screen for a quick cleaning. I wasn't able to remove the shower screen so I'll probably pop the gasket back in and avoid trying to remove the piston. After reading the threads on it on HB, I am scared to do it

Actually I did make my wife a latte at the point where I realised there was a problem, and she said it was OK. So yes, if I keep going with the lever, it fills the chamber normally, and releasing the lever puts pressure on the puck et cetera. It's just that there's now this middle stage where water is released as well.

I suppose that if I put the portafilter in from the start, I would never have known there was an issue...

Right, so if you can still make espresso, how is the taste? Same or did it take a turn for the worse?

I've had the lever behave in different ways but ultimately the coffee was good (as long as I was paying attention and dialing it in, etc).

I've pulled a few thousand PV shots without ever bothering with that lock-in-the-pf-halfway routine. If you fill the basket full and grind accordingly there will be no puck disturbance while taking the first or any of a few multiple pulls. SO you can go on pulling shots with the bad seal for a little while.

Look carefully at the piston design in the photo. The brass ring between the top two seals aligns with the inlet port in the group when the lever is a rest (all the way up). This port is a small hole (2-3 mm?) that allows the boiler water to enter group based upon boiler pressure. The seals are arranged so water can neither enter the puck nor exit the air hole in the back of the group when the lever is at rest. as the piston travels upward when the lever is pulled, the distance between the top of the middle seal and the bottom of the lower seal is how far the piston can travel before water can enter the group. If water is entering before that (or spraying out if you chose the late-lock in technique), the bottom seal is probably damaged. Sometimes these last for a long time and only act up once in a while, but eventually you'll need to replace it. Not easy, but doable, and interesting to see the inner workings of a simple, elegant design first hand. Few people appreciate how great of espresso this very simple design can make.

Here's what that piston will look like with the gaskets removed


And if I can do it.....
Anyone can do it....))

Your clamp system looks good Susan. One of the keys to success is the correct shaped clamp, with padding to protect the brass and chrome surfaces. Patience is also required. I find it easier if I remove the group from the boiler, but then one needs to have a spare gasket on hand. Also, one must be careful not to strip the four screws that bolt on the group. It's easy to overtighten them.

PC

Thanks all, that's useful. I think I understand what's happening. By chance, I have a set of seals, and I am thinking to try to cobble together some sort of clamp to push up the piston by using a part of a baby gate we have lying around here.

Bah, I've just spent about two hours on this, and screwed it up. I managed to concoct something to take the pressure, and disassembled the lever/piston bit. I got the old seals off, which I found really hard (and interestingly, one of the seals I removed seemed to be different to the other two, whereas my replacement set is 3 identical seals). I then got the new seals on, which I found really really hard.

Amazed I got this far, I started trying to reassemble the machine, but as the piston went back into its chamber, the middle seal got snarled up, and has been badly ripped

I'm giving serious thought to selling the machine to someone who is better with their hands than I am. I don't really ever want to have to do that again!