M38A1CDN2 Brake System

[Retsarge]

Hi,
I was just working on me jeep's break system. I had to replace the Master Brake Cylinder. My jeep still has the tube that is connected to the top of the master cylinder cap. This tube goes over to the jeep's air filter canister., I assume as part of the vehicle's water fording system. With this tube attached to the brake cylinder cap, it makes it very difficult to do a quick break fluid level check.
If I replace the brake cap with a non-fording equipped cap, this would allow for a easy fluid check. But what about the tube, should this be plugged? Will this have any side affects? Thanks Richard

1967 M38A1CND2
7105 96879
CFR: 67-07832