So before bleeding the brakes after installing the new caliper, I wanted to check the clearance on the MC push-pin. I loosened the MC move it out of the way. I can see there is water leaking into the nose area between the MC and the booster (rust!). I have a P30 MC with the support bracket between the MC and the booster. There does not appear to be anything to seal water out of this area. Especially with that bracket in between.
Am I missing a seal here? There is a rubber piece in the booster around the push-pin, but it appears to be too far in to mate to the M/C.