05 636. Brakes are nice and hard. Lately when I ride it gets spongy and I crack the bleeder on top. Air bubbles come out and then that's taken care of and it's solid again.

This scenario happens on and off and since I don't know the mechanics of it, will air come back into the breather and make the air bubbles? (spongy)

should I buy a new master or a new breather/nipple???

I guess I can try a new nipple since it's like $6 or $7

 

i had same problem using 636 master for my hb, got tired of dealing with it and bought 06 R1 master no problem since guess i'd try new bleeder nipple 1st