Replaced Master Mylinder(MC) and seal on Monday, re-positioned the brake reservoir directly on top of the MC with new grommets. I then attached my motive brake bleeder, without adding any brake fluid, and pumped it a few times when I suddenly noticed fluid coming out of the contact inserts caps. I looked a little closer and noticed cracks on each one. The reason brake fluid was not added was because I was going to first check for leaks in the system. The motive brake bleeder has a small pressure gauge that you can read to see any pressure drops. I don't know for sure if I would of caught the brake oil leak if I would have used the old school foot pump bleeding method because I normally leave the brake reservoir cap off when pumping. I normally use the motive brake bleeder on my Chevrolet and on my Civic. First time using it on my MBenz. I did easily remove the contact insert caps(2 caps on the reservoir) and noticed small plastic tubes that move freely up and down. I removed them only because they were already cracked and leaking. Is it normal for these capped openings to release brake fluid when pumped using a leak free adapter with air bottle that pushes air or is it because of such contact insert caps being cracked that brake fluid was able to escape and leak out. I ordered a new reservoir due to the fact that brake fluid level was hard to see anyway. I'm just hoping that brake fluid will not leak out of the new MC contact inserts..Any experiences or suggestions are more than welcomed.. 1979 300sd w116