MTS Series 505G2 SilentFlo Hydraulic Power Unit Model 505G2-30 - Manual (Page 71)

Accumulator Kit
Model 505G2.20 - 505G2.30 SilentFlo™ HPU Accessories 71
10. If you are changing the filter because the dirty filter indicator tripped, run
the HPU for two to four hours to remove contaminants. Then take a fluid
sample and have it analyzed.
Clean or change the fluid if it does not meet an ISO cleanliness level of 13/9
or better.
11. Press the Reset button on the HPU control panel to reset any interlocks and
turn off the Dirty Filter indicator.
Accumulator Kit
This section describes how to install the accumulator kit (MTS part number 054-
729-1xx).