Section III. SAMPLING AND TESTING
Carefully insert tubing into reservoir. Do not allow the
tube to touch the sides or bottom of the reservoir when
taking a sample.
Fluid samples are taken from
Hydraulic fluid, MIL-H-83282 loses its fire
approximately the same depth in the reservoir each time.
resistant properties rapidly if it is diluted with more than 3
percent by volume of MIL-H-5606 hydraulic fluid. Mixing
of the two hydraulic fluids requires determining the flash
point of the resultant mixture. The flash point should be
no lower than 3800F. This section covers sampling and
Do not drop tubes or
equipment Into reservoir.
3-2. Sampling Techniques.
(5) Allow the tube to fill with fluid.
a. Methods of Sampling. Take fluid samples
from hydraulic systems for flash point testing. Use one of
the following methods:
Do not use mouth suction.
(1) Use the tubing method to sample the
(6) Place a finger over the top of the tube
reservoir, provided that the reservoir is a part of the
blocking the hole and withdraw the tube from the
reservoir. The tube will be partially filled with fluid.
Drain the sample from the filter
(7) Insert the bottom of the tube into the
sample bottle, then release the fluid by removing the
finger from the top of the tube.
(3) Drain the sample from a line that
circulates fluid. Be careful while disconnecting the line in
(8) Repeat, until the fluid sample bottle is
order to avoid contamination of the fluid.
filled to a height of 2-1/2 inches from the bottom.
b. Preferred Method. The use of plastic flexible
Replace and tighten the cap on the
tubing for obtaining oil samples is the preferred method
and will be used whenever possible. (See para 3-3.) The
tube is used to take samples through the hydraulic system
(10) Replace the tank filler cap or other
filler neck or through the dipstick hole. Samples obtained
access covering and discard the sampling tube.
by this method are less likely to contain sludge and dirt
than drain samples. The procedure is as follows:
c. Labeling. The following information should
accompany the hydraulic fluid sample. Secure this
(1) Obtain a sample bottle and sampling tube of
information to the sample bottle with a rubber band.
proper length and diameter for each assembly.
(1) Type aircraft and serial number.
(2) Remove the filler cap or dipstick from the
hydraulic fluid reservoir.
Hydraulic system from which sample
(3) Place sample bottle cap on a clean surface
with edges up to keep them clean.
(3) Date on which sample was taken.
(4) Cut both ends off sample tube if it has fused
ends or remove protective end caps.