The hydrovac system is fail safe to resorting to normal brake operation if it fails.
Often on old trucks the hydrovac is long inoperable junk but the brakes still work okay
I have three farm trucks In this state, 2 tons and up all factory hydrovac all haven’t had proper service in perhaps 40 years and the basic brakes work with no assist.
These trucks are not drive on the road obviously.
With no load good brakes will let you lock up the tires no problem in panic braking
So don’t worry about Sunday parades
It’s safe for that without the hydrovac
You want the hydrovac when you are tailgating In modern traffic with a full load
Which you shouldn’t be doing in the first place
-s
