Thanks HB. And to you both Doug Garrott and Stefano. I have just bought parts from you and look forward to getting them and dealing with you both again.

Doug,

I still want to see that video of you standing on the spring to get the group back together

Ah now I understand. I was confused as there were two V seals on the old piston...was a second hand machine and guess it was a dodgy fix from the previous owner. Now that my replacement seals have arrived I see what they are meant to be and their placement. What you are saying is clear now and yes my drawing was wrong as it featured two V seals!!!!
Thanks a lot for the invaluable info all of you!!!!!

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

It's a trick I've learned from installing piston and oil rings on pistons in combustion engines, if it works on rings made out of steel, it should work with rubber rings as well. It takes some practice though, but it has the benefit that you can block any grooves that the ring/gasket can accidentally slip into, thus minimizing the risk of damage as Stefano pointed out, but with this method you only need to stretch the gasket a millimeter or so, and not over another gasket (which can be a tad or a lot thicker than the piston when seated depending on groove depths, gasket hardness, spring seals etc.)

If you combine this method with a lot of lube, it should be quite smooth once you get the gasket onto the piston. If you have to install several gaskets, slip on the first, set it on the middle of the piston, slide on the next gasket until all are on the piston. Then center them over the grooves and pull out the blades one by one slowly so both gaskets are seated at that particular spot before removing the next blade.

stefano65 wrote: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

I managed to replace my gaskets this weekend using this technique. I also heated the brass piston in warm water. I did not find that the gaskets slid easily but I did get them in place.

Next time I will start with the top gasket leaving the old bottom one in place to keep the new top gasket out of the bottom groove. I found it hard to get the new top gasket over the new installed bottom one.

And, my fingers are still sore.

KS