Hydraulic System

[Oscar Pacheco]

hello, if i fail any hyd pump i get EICAS msg hyd 3 lo press not hyd 3B pump msg, is this correct?, if i switch any hyd pump from on to off i get hyd 1 lo press EICAS msg before the hyd press gets below 1800 psi, is this correct?

Oscar.

[Pils]

Can you provide screenshots so we can better understand the scenarios, please?

[Oscar Pacheco]

scenario 1 hyd check.

scenario 2 hyd 3A pump failure.

 

[sunake]

Yes it is correct. From my understanding, the message is triggered when the sensors detect a loss in output pressure from the pump and not a drop in system pressure. It's done this way to quickly tell you that you're about to lose the hydraulic pressure so get ready. 

[Oscar Pacheco]

hello sunake thanks for your replay, on the expanded normal procedures item 20 you can read "After a period of time the HYD 1 and HYD 2 LO PRESS caution messages will  reappear - this is normal, the systems naturally loose pressure over time." what i understand is the hyd 3 lo press msg only is display when press is < 1800 psi.

[sunake]

Yeah I know but I'm just giving back the explanation that was given by the devs a couple of times this was mentioned.

[Oscar Pacheco]

oh, ok , thank you.