Volvo Penta DP-S outdrive leaks down overnight

[homelite]

1998 drive just atarted doing this. It was fine all winter through the PA cold. Used boat once, and now every night it goes down while sitting on trailer in yard. No external leaks. Just wondering from someone that works on these all the time what the common causes/failures are before I start ripping apart or guessing. O rings in trim cylinders or something check valve related in pump?

Onwed the boat for years and never had any trouble with this so it's obviously a new issue. Something just happened!

Diagnosis looks hard without the proper test gauges etc.

Thanks in advance.

 

[Don S]

Re: Volvo Penta DP-S outdrive leaks down overnight

Here is a Volvo service bulletin that covers that very problem.

View attachment 44-5-2 Trim Pump Repair.pdf