National Mower HYDRO HYD70OM-8/99 - Manual (Page 19)

NATIONAL HYDRO 70" TRIPLEX ®
19
8. 9—HYDRAULIC HOSES
1. Hydraulic hose and tube lines should be inspected
every week to check for cuts, loose connections,
kinks and wear.
To avoid serious bodily injury, always
lower mowers to the ground, place all
controls in Neutral and shut off engine
before inspecting hydraulic lines or
hoses. Never run hands across tubes,
hoses or fittings to check for leaks.
2. Be sure tubes and hoses do not come in contact
with other frame parts which could cause abrasive
wear. Always replace worn hoses or tubes before
operating machine.
a. Assemble nut, sleeves, and tube to fitting body
with minimum torque (finger tight) until flare contacts
seat on fitting body.
b. For tightening reference, mark a line lengthwise
on both the nut and adapter fitting with a marker.
c. Using a wrench, rotate the nut to tighten. Turn
the nut the amount shown in the chart following. The
line will show which fittings have been tightened and
how much.
d. On hoses with “O” ring fittings, make sure “O”
rings are clean and hose fittings are properly seated
before tightening.
3. Hold the fixed portion of the hose coupling with one
wrench; use a second wrench to tighten or loosen
the hose nut. This will prevent damage to the fitting
seal. When tightening a hose, do not allow it to
twist; hold it in a normal straight portion.
Tube O.D. or Hose I.D. Rotate No. of Hex Flats
3/8" 2
1/2" 2
5/8" 1-1/2 to 2
1" 3/4 to 1
8.10—HYDRAULIC OIL
1. The reservoir should be checked daily for proper
level in the sight glass gauge on rear of the oil tank.
Oil level should be seen in the sight glass.
2. Park the tractor on a flat or level surface. Fully
lower all cutting units.
3. Oil should be at 60 F to 90 F (16 -32 C), when
checking level. Do not check oil level when oil is
hot.
4. Drain and replace the hydraulic oil every 500
hours. Use Hydraulic oil as listed in 3.7 of the
“Specifications” section of this manual.
a. The oil should be changed after a major
component failure, or if you notice the
presence of water (noted by a cloudy or milky
appearance), air (noted by foam), or a rancid
odor (indicating excessive heat).
b. Once a year check the breather element in
the tank cap and replace if necessary.
5. To drain hydraulic oil tank, remove drain plug from
bottom of tank and loosen to remove fill cap on top
of tank.
6. Reinstall drain plug and fill hydraulic tank to full level
on sight gauge, use only filtered hydraulic oil. The
total hydraulic system oil capacity is approximately
5 gallons.
7. Jack up front tires so they spin freely.
8. Start engine: operate the traction pedal and cycle
lift cylinder for a minimum of three minutes.
Recheck oil level in sight glass gauge.