EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
General Maintenance Action
Aircraft
During flight we received a EICAS message of Hydraulic Low Quantity in cruise.  MFD showed System 1 in amber.  Notified Maintenance Control via ACARS and they advised if fluid is not dropping any further continue.  We continued monitoring the systems.  On the descent the First Officer was using the spoilers for descent and he advised me that they were not closing when he selected them closed.  By the time I looked at the indicator they had closed and he advised me that it was odd that it took longer than normal to close.  I checked the hydraulic system and at the time system 1 was holding good pressure but still in amber and system 2 had good quantity with good pressure.  On very short final we got the EICAS Brake Degrade message.  Hydraulics still showed good so we continued after we briefed use of reverse thrust and emergency brake if needed.  Landed fine; thrust reverse worked along with normal braking.  I took control of the aircraft and taxied to the gate.  This is where we set the parking brake and heard this loud hissing noise coming from the aircraft.  At that moment  we also got Emergency Brake Low Pressure EICAS and Hydraulic System 2 quantity was rapidly going down.  I advised ground personnel that we were losing brakes and asked if the chocks were in.  They said yes and I secured the engine; hydraulics and released the parking brake to stop the hissing noise.  The ground crew advised us of a large puddle of hydraulic fluid under the right main gear.  We wrote the loss of all hydraulics including the emergency brake in the maintenance log.  This is the first time I have had loss of all hydraulics and the backup emergency brake at the same time.  Thankfully we were chocked at the gate. It appeared that the emergency air brake bottle was pushing the remaining hydraulic fluid out of the aircraft.  Leak stopped when I secured the pumps and released the brake. Inspect the aircraft more frequently and keep the hydraulic systems topped off  to full.  That will give you more time in the event of a leak.  I have had Maintenance in the past say that if the hydraulic system is in the green it's good to go.  Even if it is almost touching the caution zone on the MFD.
EMB145 Captain experiences low hydraulic quantity in system number one during cruise and continues to destination. On short final an EICAS Brake Degrade message is displayed; discussed and a normal landing ensues. When the parking brake is set a loud hissing noise is heard and rapidly declining hydraulic system two quantity is noted. With the chocks in the engine is shut down and the parking brake is released. A large puddle of hydraulic fluid is reported around the right main gear.