Service Manifold Manual

5. Wipe the filter base dry with a clean, lint-free cloth and visually check the main seal and back-up ring
for damage. If necessary, replace them with new seals from the pilot filter service kit.
6. Check the filter bowl for signs of contamination (particles adhering to the inside of the bowl). If
contamination is present, check the system for wear or loss of seal integrity.
Warning:
Re-using a dirty filter can introduce contamination.
Contaminated hydraulic fluid can cause premature wear of the hydraulic components in
your system.
Do not re-use filter elements.
7. With a small amount of clean hydraulic fluid, lubricate the main seal, back-up ring, and internal seal of
a new pilot pressure filter.
8. Install the new filter element and turn the bowl clockwise until it is hand tight.
9. Reset the pilot filter indicator by pressing it down.
10. Remove and empty the drain pan. Replace the cap on the drain port fitting. Replace the vent plug.
Tighten it to 47.5 N·m (35 lb·ft).
11. Remove any specimen from the test area and turn on electrical power. Activate the HPU in low and
then high pressure mode. Operate the actuator for at least five minutes to bleed air from the pilot
circuit(s).
Checking the Accumulators
The accumulators have a pressure charge of compressed gas. The accumulator’s correct precharge
pressures are recorded on their labels. The precharge pressure should be checked once a month.
Warning:
Do not charge the accumulators with gases other than pure (commercial grade, dry) nitrogen
gas.
Using unacceptable gasses can cause personal injury, damage to equipment, or both.
Refer to the accumulator manual for information about charging the accumulator.
The recommended accumulator precharge levels for an HPU output of 21 MPa (3000 psi) are as follows:
PrechargeAccumulator
7 MPa (1000 psi)2Main pressure
2 May be varied according to system performance.
Model 293.32 Hydraulic Service Manifold | 49
Maintenance