Said everyone who ever owned a roof mounted bike rack, myself included
Had a bit of a low bite point on the front lever on my mates Banshee, decided to give the brakes a quick bubble bleed, bubbles came out, but lever was still not great. Decided to change the pads from front to rear, also to compare the pads, and yes the front were quite worn down, the rear pads were giving a very high bite point now on the front.
While putting the bike back together, I was struggling big time with the rear wheel alignment and getting the axle through. Got it there in the end, after twice getting it there but the chain wasn't over the cluster. But the worn pads on the back were way worse than they were on the front. Decided to bleed the back, lots of bubbles. On that bleed I managed to remove the bleed cup without putting the stopper pin in. Doh!
Then realised it was much easier to re fit the back wheel when you take the chain off the chainring and have no tension. Duh!
Then rode it and the lever was terrible. Thought to myself those pads are really fucked. Then went to put the bleed cup away and it had two o-rings on it, so repeat bleed process reinstalling the o-ring. This time I realised the 4 pot brakes can fit two of the brake blocks, so I re-do both ends to make sure everything is even after having only used a single brake block before, and forget the stopper pin again, but only once, and only dripped it on the floor and one drop on the fork leg.
Talked to my mate, he has spare pads, luckily I shouldn't need to use the bleed cup to fit them.