Table 2-2. Troubleshooting Procedures (Continued)
TEST OR INSPECTION
EXTERNAL LEAKAGE AROUND PORTS OF CONTROL VALVE:
Check for scratches or other physical damage to threads.
If thread compound fails to effect a solder so that when the pipe is screwed back
into valve it will in effect re-cut the threads. Use Litharge and glycerin for a thread
seal any time the piping is changed.
EXTERNAL LEAKAGE BETWEEN BODY AND HOUSING OF CONTROL VALVE O-RING:
Check for improperly installed body O-ring.
Check for excessive back pressure in the housing caused by restricted return flow or
valve being connected with pressure on return port. This back pressure may cause
bolts to stretch and allow fluid to leak out between body and housing.
Check return pressure with pressure gage and remove restriction. Install valve
according to port markings. (Refer to TM 5-3895-372-20.)
Check for high velocity caused by extreme volume of fluid being forced through valve.
With fluid velocities greater than 30 feet per second, a jet of fluid hits the body O-ring
when the valve is in an intermediate or inter flow position. This high velocity jet goes
past the O-ring and through the crack between body and housing castings
Install a velocity shield ring which will correct this condition, or replace old style
housing with a new one which has a fully contained O-ring groove (para 3-13 thru
HYDRAULIC MOTOR LEAKS:
Check for leaking hose fittings.
Check for leaking oil seals.
Check for leakage at special bolts.
Torque leaking bolt to 50 Ib-ft (68 N-m). Replace bolt.