JLG 4394RT Service Manual - Manual (Page 205)

SECTION 4 - HYDRAULICS
3121249 – JLG Lift – 4-39
Oscillating Axle Cylinder Bleeding Procedure
1. Start the engine.
2. Raise the arms high enough so that the left axle cyl-
inder bleeder valve can be accessed.
3. Let engine run at idle.
4. Position a suitable container [approx 0.5 gal (1.9 ltr)]
over the bleeder valve.
5. Using a 3/8" wrench, slowly open bleeder valve.
6. Keep the container close enough to the bleeder
valve to catch the aerated oil.
7. Open the bleeder valve enough to get a fast stream
of oil.
NOTE: A fast stream of oil will exhaust the air out of the
hoses and cylinder better than a slow stream of oil.
8. Every 3-4 seconds, close the bleeder valve so that a
slower stream of oil is being purged. When only oil
and no air is being purged, close the bleeder valve.
9. A new system can take 10-15 seconds per cylinder
to bleed.
ANYTIME EITHER OF THE HOSES PLUMBING TO THE CYLIN-
DERS ARE BROKEN INTO, AIR HAS BEEN INTRODUCED INTO
THE SYSTEM. THE CYLINDERS MUST BE BLED.
2
1
1. Oscillating Axle Cylinder 2. Bleeder Valve
Figure 4-35. Oscillating Axle Cylinder Bleeding