Hydraulic Lines and Fittings
If a rigid tube is too short for the flare to reach its seat before tightening, pulling it into place by tightening
may distort the flare.
What would be the effect if the piston return spring broke in a brake master cylinder?
The brakes would drag.
The best safeguards against heat buildup in aircraft tires are
short ground rolls, slow taxi speeds, minimum braking, and proper tire inflation.
Characteristics of MIL-H-7644 hydraulic fluid are
blue color, vegetable base, will burn, natural rubber seals.
To protect seals from damage when installed over a threaded section, the threaded section should be
covered with a suitable sleeve.
What is the color of an AN steel flared-tube fitting?
Black.
The pressure source for power brakes is
the main hydraulic system.
What action, if any, should be taken when there is a difference of more than 5 pounds of air pressure in tires mounted as duals?
Correct the discrepancy and enter in the aircraft records.
Phosphate ester base hydraulic fluid is very susceptible to contamination from
water in the atmosphere.
What is the purpose of using backup rings with O-rings in hydraulic systems above 1,500 PSI?
Prevent high pressure from extruding the seal between the moving and stationary part.
The primary purpose of providing suitable bends in fluid and pneumatic metal tubing runs is to
prevent excessive stress on the tubing.
In brake service work, the term 'bleeding brakes' is the process of
withdrawing fluid from the system for the purpose of removing air that has entered the system.
Excessive wear in the center of the tread of an aircraft tire is an indication of
over inflation.
Two types of hydraulic fluids currently being used in civil aircraft are
mineral base, and phosphate ester base.
A flexible sealing element subject to motion is a
packing.
Quick-disconnect couplings in hydraulic systems provide a means of
quickly connecting and disconnecting hydraulic lines without loss of fluid or entrance of air into the system.
Aside from an external leak in the line, what will cause parking brakes to continually bleed off pressure?
An internal leak in the master cylinder.
The primary purpose for balancing aircraft wheel assemblies is to
prevent heavy spots and reduce vibration.
Characteristics of MIL-H-8446 (Skydrol 500 A & B) hydraulic fluid are
light purple color, phosphate ester base, fire resistant, butyl rubber seals.
Generally, the first step in removing an accumulator from an aircraft is to
relieve system pressure.
Hydraulic tubing, which is damaged in a localized area to such an extent that repair is necessary, may be repaired
by cutting out the damaged area and utilizing a swaged tube fitting to join the tube ends.
A fully-charged hydraulic accumulator provides
a source for additional hydraulic power when heavy demands are placed on the system.
The removal, installation, and repair of landing gear tires by the holder of a private pilot certificate on an aircraft owned or operated is considered to be
preventive maintenance.
Characteristics of MIL-H-5606 hydraulic fluid are
red color, petroleum base, will burn, uses synthetic rubber seals.
A unit which transforms hydraulic pressure into linear motion is called
an actuating cylinder.