Troubleshooting; Preliminary Checks - Mercury 40 Service Manual

POWER TRIM

Troubleshooting

Support outboard with tilt lock pin when servicing power trim system.
IMPORTANT: After debris or failed components have been found (during trouble-
shooting procedure), it is recommended that unit be disassembled completely and
ALL O-rings be replaced. Check ball valve components and castings must be
cleaned using engine cleaner and compressed air or replaced prior to re-assembly.
IMPORTANT: Power trim system is pressurized. Outboard must be in the full "UP"
position (trim rod fully extended) prior to fill/drain plug, or manual release valve re-
moval.
Refer to instructions following if disassembly is required when servicing.
Follow preliminary checks before proceeding to troubleshooting flow diagrams (following).

Preliminary Checks

IMPORTANT: Operate Power Trim system after each check to see if problem has been
corrected. If problem has not been corrected proceed to next check.
1. Check that manual release valve is tightened to full right (clockwise) position.
2. Check trim pump fluid level with outboard in full "UP" position and fill if necessary. Refer
to "Bleeding Power Trim Unit".
3. Check for external leaks in Power Trim system. Replace defective part(s) if leak is found.
4. Outboard not holding tilted position (falls down to trim position) indicates debris or defec-
tive components in trim assembly. Clean or replace components as required.
Page 5C-22 90-828631R3 MARCH 1999