Inspection, Service and Maintenance
Bri-Mar
130
8.2.9.2 DC Power Unit Troubleshooting
The single acting system (M-319) operates the motor in the UP position
only. Fluid is pumped through a check valve to the cylinder. When the
pump is stopped, the check valve prevents the fluid from returning back
to the tank through the pump. The pressure to raise the body will vary
depending on the trailer type, body angle and load. If the load is
extreme, the relief valve will limit the pressure to the cylinder and the
load will not move.
A single acting system is a gravity down system. The lowering speed
will vary depending on the trailer type, body angle, load and oil
thickness. During lowering, the 2 way valve opens connecting the
cylinder directly to the tank and exhausting the fluid from the cylinder.
Lowering the body with a load can be rapid. Caution should be used
when lowering the body with a load.
The double acting system (M-3551) operates the motor in both UP and
DOWN operation. Selecting UP energizes the 4 way 2 position valve and
the pump. The oil flows from the pump through the check valve, 4 way
2 position valve, flow control valve and the 2 way 2 position valve to the
cylinder piston side. The rod side is connected through the 4 way 2
position valve directly to the tank.
Selecting DOWN energizes the 2 way 2 position valve and the pump.
The oil flows from the pump through the check valve and the 4 way 2
position valve to the cylinder rod side. The piston side oil flows through
the 2 way 2 position valve, flow control valve and the 4 way 2 position
valve to the tank.
The flow control valve controls the decent speed of the body to prevent
overrunning the pump.
If the pump will not operate, check the level of charge in the battery and
also for blown fuses. If these check out, contact your dealer for
assistance.
Trailers
Summary of Contents for DT508LP
Page 144: ...Electrical Drawings Bri Mar 138 Trailers...
Page 145: ...Bri Mar 139 9 ELECTRICAL DRAWINGS Trailers...
Page 146: ...Bri Mar 140 Trailers...
