Manifold And Hydraulic Pumps; Hydraulic Brake Pressure Adjustment - Skyjack SJ60AJ+ Service Manual

Manifold and Hydraulic Pumps

5.7 Manifold and Hydraulic
Pumps
5.7-1 Hydraulic Brake Pressure
Adjustment
Maintaining accurate hydraulic brake pressure is
important when it comes to safe MEWP operation.
1. Locate brake system pressure reducing
valve PR1 . Loosen the lock nut and turn
1
the adjustment stem gently clockwise until it
bottoms out, while keeping track of the number
of turns.
1
CAUTION
Valve damage will occur if it is tightened too much.
WARNING
Ensure that there are no personnel or obstructions
in the test area and there is sufficient room for
forward or reverse travel.
2. Start the engine from the platform controls and
extend the boom slightly to achieve low speed
drive.
SJ60AJ+
2
3. Drive the MEWP forward or reverse. The
pressure gauge reading should be 38 bar (550
psi). Stop the MEWP . Follow the next steps for
adjusting the relief valve pressure if needed. If
no adjustment is required continue to step 8.
4. Locate the brake pressure relief valve RV7
and loosen the lock nut.
5. Turn the adjusting stem on pressure relief valve
RV7 one quarter of a turn at a time clockwise
2
to increase pressure, or counterclockwise to
decrease pressure. Drive the MEWP forward or
reverse, note the pressure, and stop the MEWP .
6. Repeat step 5 until the brake pressure is
achieved (38 bar/550 psi) then tighten the lock
nut on brake system pressure relief valve RV7
.
2
7. Locate the brake system pressure reducing
valve PR1 and turn the valve gently
1
counterclockwise back to the to initial position.
8. Drive the MEWP forward or reverse. The
pressure gauge reading should be 34 bar (500
psi). Follow the next steps for adjusting the
reducing valve pressure if needed.
9. Stop the MEWP and adjust the pressure
reducing valve PR1
time by turning either clockwise to increase the
pressure, or counterclockwise to decrease the
pressure.
10. Repeat steps 8 and 9 until brake pressure is
achieved (34 bar/500 psi), then tighten the lock
nut on brake system pressure reducing valve
PR1 .
1
Section 5 – Procedures
2
one quarter of a turn at a
1
238275AAA
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