Ashland 1200 TR - Manual (Page 33)

33
TROUBLE SHOOTING YOUR HYDRAULIC SYSTEM
PROBLEM POSSIBLE CAUSES REMEDY
No pressure in the Pump does not deliver Follow the remedies given for
system pressure "Failure of Pump to Deliver Fluid".
Bad pump-to-motor shaft Check pump/motor coupling
connection for breakage. stripped key or
keyway and replace or repair
Relief Valve Malfunction
1) Incorrect valve setting 1) Reset to specifications
2) Valve leaking or by-passing 2) Check main valve seat &
pilot valve for scoring & dirt.
Replace & clean.
3) Valve spring broken 3) Replace spring and reset.
Free re-circulation of oil to tank Check or relief valve may be
being allowed through system. stuck in open position or return
line open unintentionally.
Vent Valve* is dumping flow
through relief valve at low
pressure.
Bypass valve to tank is open.
Open center 4-way Valve* is
not shifted, dumping oil to tank.
See “Solenoid Valve not
Shifting" if valve is solenoid
operated.
No pressure In circuit Pressure compensated pump Check compensator for broken
with Variable Volume not compensating properly. spring or contamination and
Piston Pumps repair as required.
Relief valve setting is lower Set relief to max system
than pump compensator pressure and pump
setting compensator to operating
pressure at least 250 psi
below relief
Hydrostatic drive not building See remedies in “Hydrostatic
torque (no system pressure) Circuit Troubleshooting" section.