Now it's time to install the new seals.

One trick that seems to work to make the upper seal easier to install is to cut off the raised lip on the upper elbow. This lip seems to be of dubious value, and causes a lot of trouble.

It can be cut off with a sharp razor blade, though be careful when doing this.

As you can see, after modification the new upper seal sits in the upper end of the elbow easily. It will still seal well when clamped down as the lip is not part of the sealing surface.