5-50. HYDRAULIC SYSTEM COMPONENT TESTING - Continued
(1) Visually inspect the hose for cuts, abrasions and evidence of fluid leakage on the outer surface and
delamination of the lining.
Delamination often appears as a bubble and is normally seen
near the metal coupling.
(2) Replace any hose that is suspect.
d. Main Hydraulic Pump.
(1) Disconnect the pressure sensing line from the manifold block that the pressure relief valve (pump de-
stroke) is mounted to and plug it.
(2) Plug the port on the manifold block.
(3) Connect a 0-3000 PSI (0-20,000 kPa) direct pressure reading gage in the outlet of the hydraulic pump.
(4) Start engine and engage the P.T.O.
(5) If pressure is 2100-2150 PSI (14,469-14,814 kPa), the pump is serviceable.
(6) If no pressure reading is obtained, remove the hydraulic pump (see para 5-61) and inspect the P.T.O.
output shaft for damage (see para 5-49).
(7) If the P.T.O. output shaft is not damaged, replace the hydraulic pump (see para 5-61).
(8) Remove the test gage from the pump and reconnect the sensing line to the manifold block.
e. Pressure Relief Valve (Pump De-Stroke).
This procedure should be done after pressure relief (de-stroking)
valve not functioning procedure found in electrical trouble-
(1) Disconnect the return line from the manifold block.
(2) Install a test hose at the port the return line was disconnected from.
(3) Place the test hose in a five gallon (20 liter) container.
(4) Place aerial/outrigger switch to outrigger to remove power to de-stroke valve.