Mariner 100, Service Manual, Page: 230 / 391

6A-6 POWER TRIM 90-13645--2 495
Hydraulic System
Troubleshooting
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 knob is tight-
ened to full right (clockwise) position.
2. Check trim pump fluid level and fill if necessary.
Refer to “Filling and Bleeding the Power Trim Sys-
tem,” preceding.
3. Check for external leaks in Power Trim system.
Replace defective part(s) if leak is found.
4. Check for air in Power Trim system and bleed if
necessary. Refer to “Filling and Bleeding the Pow-
er Trim System,” preceding.
Do not remove check valve from port trim rod.
Check valve is preset to operate at a specific
pressure. Removal and reinstallation of check
valve could result in improper operating pressure
and possible Power Trim system damage.
CAUTION
5. If engine will not hold a tilted (trailer) position
(leaks down to trim position) – Remove port trim
rod assembly from Power Trim housing; refer to
“Trim Rod Removal,” following.
Inspect check valve (located in port trim rod) for
debris; clean debris from check valve if found. If
debris can not be cleaned from check valve, re-
place trim rod and check valve as an assembly.
Inspect trim rod O-ring and replace if damaged.
Reinstall trim rod in housing; refer to “Trim Rod
Installation,” following.
6. Disconnect trim pump motor wires, and remove
starboard transom bracket from engine. Refer to
“Removal” instructions in “Power Trim Assembly
Removal and Installation,” following.
Slowly remove fill screw to bleed pressure from
reservoir.
Place a pan under manual release valve, and
slowly remove valve. Inspect the valve and O-
rings for damage.
If damaged component(s) are found, replace
component(s) and proceed to STEP 9.
If damaged component(s) are not found, reinstall
manual release valve and proceed to STEP 7.
7. Remove Power Trim assembly from engine; refer
to “Removal” instructions in “Power Trim Assem-
bly Removal and Installation,” following.
Disassemble Power Trim assembly; refer to “Trim
Rod,” “Tilt Ram,” and “Pump Replacement,” fol-
lowing. Inspect O-rings for damage. Inspect
check valves for debris that could cause them to
remain open.
If O-rings are damaged or debris is found, replace
O-rings or clean debris from check valve(s), then
reassemble Power Trim assembly and proceed to
STEP 9.
If damaged O-ring(s) or debris are not found, pro-
ceed to STEP 8.
8. Replace pump assembly; refer to “Pump Re-
placement,” following.
9. Install Power Trim assembly and/or starboard
transom bracket, steering retaining nut (models
with thru-tilt tube steering) and motor wires; refer
to “Installation” instructions in “Power Trim As-
sembly Removal and Installation,” following.