Leaky Hydro Reservoir Cap???

[John Larson]

Years of this subject and it's still not clear.  Replacing the "bomb" does
not and cannot increase the pressure.  The bomb is a reservoir, and its real
name is "hydraulic accumulator".  It stores fluid under pressure, the
pressure provided by the pump.  It does NOT make pressure. The problem
you're experiencing has been discussed many times in the past on this list,
and should be in the archives.  The cap is vented, and a leak from that vent
indicates fluid being pushed out through that vent.  I'd look at the pump.
HTH, John