Developed a dripping grouphead in a ~6y/o Elektra Microcasa a Leva (MCaL). So today I replaced the piston seals.

No being the brightest bulb in the room I thought you had to remove the lever then just unstack the spring, seals & piston. WRONG! Became apparent while removing the pivot rod that there is a bit of preload on the spring. Too late. Removed the lever to find out the piston does not unstack. Pried off the old hard relative to the new seals. Heated up the new seals in some hot water. Not sure if it makes any difference in ease of stretching the seals. Stretching on the new seals is sort of like mounting a too tight tubular bicycle tire. But no sticky mastik to deal with.
Down to the woodcarving bench to clamp the unit together. There is no way without a vise/clamp you will be able to preload the spring. I would recommend using a vise/clamp if you plan to remove the lever & pivot rods. Got lucky and everything aligned up the first time.

Lubed up the seals with some food grade silicone grease. Inserted.... Well not really. New seals are real snug. With the old seals I have been able to easily remove the piston unit, clean the bottom of the piston and pop out the dispersion screen/gasket for cleaning. Replacing the piston unit was no problem. With the new seals you need to feed the gaskets into the piston chamber. What worked for me was applying significant firm pressure with the fingernail while rotating the whole piston unit around. Once the edge is in there is no problem in feeding in the rest of the gasket.

Dan, any chance of adding a FAQ for specific lever machine regarding subjects such as gasket/seal replacement. Not sure if I'm the only person who has found out by experience the right & wrong way of doing things. Sure will make life easier. There is always the Search function, but at FAQ would be real convenient.

narc wrote:Dan, any chance of adding a FAQ for specific lever machine regarding subjects such as gasket/seal replacement. Not sure if I'm the only person who has found out by experience the right & wrong way of doing things. Sure will make life easier. There is always the Search function, but at FAQ would be real convenient.

Steve's instructions Refeathering the Peacock - Pavoni head gasket replacement basically apply to the Microcasa, including tips on slipping the gaskets into place. You can find it linked from the FAQs and Favorites along with this thread.

On the pavoni refeathering post it says the Vs always point away from the centre. Is this the same for the Elektra MCAL. I thought they were opposite to the Pavoni? Must sort this before I put the new seals in. Yes I made the fatal mistake of removing the old without pics or the new seals!!!AHHHHH

From Elektra/Pavoni side by side:



And a close-up:

Narc,

for what it's worth now, many people don't bother disassembling the piston to change the seals.

Cheers

Mike

Tip for getting all kinds of gasket and rings onto pistons. Get a set of feeler gauges. Open it up so you can separate the blades. Take a couple of similar thickness and hold them to the piston. Now slip your ring over the blades, and start to force it onto the piston by using the blades for leverage to get the ring into place.

Thanks for the close up pic Dan HB. It looks to me as the cross section here. Am I correct? Don't want to do the hard graft to find I stumble at this all important stage.

Your diagram doesn't look right because there are two gaskets: Piston gasket "V" and Piston Gasket "W". Espressocare.com has drawings with numbered parts here. The "V" gasket points downward. Think about it... if the V was was pointing up, it would not "jellyfish" open on the downstroke and water would slip by easily.

By now you have learned the lesson of not removing the spring from the Elektra to change the seals, the hard way, but a lesson well learned.....as far as the seals go, any seals and some are real buggers to install. Elektra are tough since they are so hard and Ponte Vecchio are similarly difficult to stretch over the piston. Be thankful that you have but two to install not 3!

I find that on any piston, installing seals is easier if you lube the entire seal, inside and out, with Dow 111 so you can work it a little better when seating it in the groove. When you have the spring in place you have to install the upper seal first so you orient it as you want it (the v or leading edge down) and then you roll it and push it using a blunt probe or favorite tool.... some piano tuner's tools work really well, or a specially made blunt awl. You can actually roll a seal inside out and with the lube continue to travel it out of the first piston groove to the second. On a commercial piston with spring in place you have to travel the upper seal past the lower 2 races so there is a lot of huffing and puffing but if your start out with the seal in the proper orientation it will end up in the proper orientation.

On the Elektra, I place the piston and leading W seal at the top of the cylinder and wiggle the entire piston spring and lever assembly in a rotating motion while pushing down and with the other hand use the same blunt tool to shoehorn the seal into the cylinder, making sure that no edges are sticking out as to be torn or damaged. Since the Elektra is a straight cylinder with no expanded upper air horn on the group you can pretty much see any part of the seal that needs to be tucked in. If there is a big airhorn on the group and the first seal cannot be touched with a tool or even seen my method is to do this rocking and rolling of the piston on top of the cylinder, almost to a 45 degree angle and then reduce the angle while furiously rotating the entire piston assembly in smaller and smaller circles until I can feel the circles constrict and the assembly is defaulting to vertical.....then it is in.

Stugi's feeler gauge idea is pretty good, hadn't thought of that one, but then Stugi has things pretty well figured out.

soak the new gaskets in hot water for a while they will get softer and will stretch over the brass very easily
first insert the bottom one so then to top one will not get inside the wrong groove taking the chance to damage it to stretch it out again