I hope you decided to replace all the o-rings after taking the trim cylinder apart otherwise, you are just wasting time and efforts, even if all the o-rings look good. The test procedure does not require to push any of the cylinders, tilt or trim. Instead, it requires monitoring of the motor to see if it is drooping down or not from a full tilt position. Deviating from the test procedure complicates diagnosing and should be avoided.
And please focus only on one unit for now. You cannot be testing one unit and be discussing the spare unit at the same time. The leak down test is really not that complicated. First you test for the tilt cylinder; if that is good then you test both tilt and trim, and if that is good that means the VB is causing the leak down. But if on the second test there is a leak down , then the cause is the trim cylinder. Or if the first test indicates leak down, then the tilt cylinder is causing the leak down.
