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" | 3/4 to 1 |
NATIONAL® HYDRO 70" TRIPLEX
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
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.
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