I have the old style bravo-1 drives, 1988's, and the problem is when they sit for a period of time, overnigh say, the port drive won't stay trimmed up.
There are no visable leaks that I can see.
Can this be the trim pump going south?

could be internal leak in the cylinders. purge the system to remove any air.

There are some check valves in the trim pump too. The kit is available, but I've heard that it can be tricky to install.

What Cord said: And the kit comes with good instructions, so if you are patient and willing to follow the directions, I'm sure you can solve this problem at home with basic tools. --- Jer

http://www.mercruiserparts.com/Show_...ttom+Mounted+R<br%20/>ese

I have same problem with my port drive. Here is BAM part list.

http://www.offshoreonly.com/forums/s...highlight=trim

Also, here is my thread with lots of good info.

Thanks for the good info.
I'll tear, er, look into it this weekend!

A friend of mine had same problem. His was worn out piston seals in the rams.

US1: is there anyway to determine if seals are worn? Mine are not leaking at all. I guess I could swap from starboard and see if problem is still there.

theres also an o-ring at the pump. mine did the same. replaced o-ring, no more problems