Hey Russ,
The Bravo is designed to work under pressure. If you have a leak any where you will see the Gear Lube bubble and rise in the reservoir. Not sure why you are having O-ring problems. Are you torquing the Drive on tight enough?
Dan

Russ SR1,
My recent purchase had the same problem (96 with Bravos). Turns out the oil in the drives hadn't been serviced properly. If you look closely at the base of your reservoir you may find what I did (a thick sludge).

When the drives warm up, the oil expands and tries to go into the reservoir. The reservoir cap has a vent to relieve this pressure. When the pressure reached the sludge it built up until it blew through the sludge and popped the cap off. I removed and cleaned the reservoir, completely drained the drives and replaced drive oil and topped off to level. I've never had a problem since.

Hope this helps!

Thanks marinetrans I will try it out.

boatnick I will take a look, sure hope theres no sludge anywhere on the formula

Hey Dan how are you and Vicky doing? Baby Shannon came out fine last Sept. so this year the boating might get back to normal. Great thing about it, the wife said go buy a bigger boat with more cabin. So boat shopping I am. I can't wait to see everyone on the water this year.