OK, installed the 4 o-rings and took a 25 mile ride in 80F weather yesterday. Covers did not leak! Attached is a photo of the packaging from McMaster-...

Darren, I had to stretch it a little to get it in, but not much. The old ring I removed was smaller when compared side by side with the new ring. Th...

Winner winner, chicken dinner! Looks like the McMaster 155 size is the winner. 155 was larger in diameter than the old ring I took off but when I put ...

Thanks, Richard. Had no idea McMaster had that. Darren - I ordered 3 sizes so hopefully one will work. I may have to go up to 1/8" if 3/32" is ...

Thanks for that info! I just had a look at McMaster-Carr and they have a 3/32" (2.6mm) Viton o-ring at 3.987", which is pretty close to your 103mm siz...