Tighten the bolts? Align the lid?

 
I have never found a project that not require some new tool. My moto is if I can do a project that requires new or more tools, then go for it.

Do a dollar bill test on your egg. If the seal is good then just snug up the bolts - don't break them. The band bolts should be tightened to where the bolts bend.

GG

GG is eggactly correct. Test with $$ bill. If it is snug all around - leave it alone.

After a few months of gasket testing cooks, I began to develop slight smoke escape in the rear. I loosened both bands and got the gap closed enough to pass the $$ bill test again. This occurred every 6 months until now (4 years later) there is only a slight coloration where the gasket used to be. I'm fortunate that my top and bottom seem to fit perfectly together. I truly believe that keeping the alignment gap tight will prolong the life of your gasket.

When you look at the top band - is it touching the top of the groove all the way around?
When you look at the bottom band - is it touching the bottom of the groove all the way around?

For my LBGE, that is where they are and the open/close seems to work eggactly right (think of how the pivot point is behind and must let the two come together.)

 
If you have a large or smaller then close the dome and look at the front to back and side to side alignment of the dome and base.

The bands can be torqued when off of the egg and that will sometimes cause a left/right or front/back misalignment with the dome to base.

Pushing the dome with the bands on will only put pressure on the hinge assembly and usually won't correct that problem - I wouldn't recommend trying to push a dome back into alignment. Rather, if the dome is really off, remove the bands and hinge assembly. Set the bands on a flat surface. If the band is twisted, not sitting flat on the surface, slightly twist one or both bands to get it setting flat.

If needed put the bands on the hinge and have 2 people lift the band assembly on the the base of the egg. Hinge in closed position, put the dome on the egg, through the upper band. Make sure the dome is aligned with the base. If the dome or base is out of shape then you may need to talk with the dealer. However, they should match.

Just snug the lower band bolt and upper band bolt. Make sure both bands are as close to the molded 'band stop' as it can be. Tighten the bolts about half way tight, recheck the bottoming of the bands to the ridge in the base and the ridge in the dome.

Tighten again where the bands are very tight, the bands should have not slipped up or down. If the bands are still bottomed and the bands are very tight you could do the dollar bill test.

A loose pull or no resistance pull is bad. A snug or feel like the paper/bill is going to tear is good. Don't expect the pull to be the same all the way around the egg.

If your egg passes the dollar bill test then finish tightening the band bolts to the 'bolt bend' point.

If you don't have an XL I would think the adhesive gave way and the pull was from adhesive failure of the adhesive oozing through to the other gasket, hence the pull off and or movement of the gasket.

It is possible you have a bad gasket and it needs replacing under warranty.

Now, for the trailer, get it anyway. You will need it for the old gasket or if the surface is flat enough then use that to test the possible torque in the bands.

GG