SERVICE MANUAL NUMBER 28
TROUBLESHOOTING
Power Trim Hydraulic System
NOTE:Refer to “Power Trim Hydraulic Schematic.”
Drive Unit Cannot Be Trimmed OUT/UP Or Trims Slowly Or With Jerky
Movements
Cause
Special Instructions
Check for cause of low oil level and
correct. Add oil and bleed trim system.
Power trim pump oil level low.
Check for cause of entry and correct.
Add oil to pump and bleed air from
system.
Air in trim system.
O-rings damaged on Manual Release
Valve (if equipped) or valve not
completely closed.
Replace valve and/or close completely.
Test. If shuttle 1 is stuck, replace
pump adaptor (Refer to SECTION 5A). If
pressure is low, replace adaptor or
attempt to repair by replacing the
Insufficient pump pressure or pump.
shuttle valve stuck.
followingD
components:
D TOUT/UPhermal RPressureelief ValvReliefe
Valve
Hoses reversed on one cylinder only.
Trim cylinder(s) binding.
Connect hoses 7 and 8 correctly.
Check for cause of binding (bent
piston rod, scored cylinder).
Repair or replace as necessary.
Gimbal housing-to-trim pump hydraulic
hose pinched.
Replace hose 7.
Up pressure relief valve has dirt
particles under check ball.
Replace with a new valve kit.
Drive Unit Will Not Stay In Trimmed OUT/UP Position
Cause
Special Instructions
Check for cause of entry. Fill and bleed
system.
Air in trim system.
Check for dirt. Install new poppet
valve.
Shuttle valve (poppet valve).
Sterndrive Unit Trails OUT/UP On Deceleration Or When Shifting Into Reverse
UNIT THUMPS WHEN SHIFTING
Cause
Special Instructions
Test according to appropriate service
manual. Replace adaptor or attempt to
repair by replacing the pilot check
valves or seals. (Install Trim Pump
Rebuild Kit)
Trim pump IN/DOWN circuit leaking
internally.
INDEX
90-863160
MAY 2000
Page 1C-17
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | MerCruiser Sterndrives 90-863160 |
| Model Year | 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 |
| Download File |
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| Document File Type | |
| Copyright | Attribution Non-commercial |
(1 votes, average: 3 out of 3)
Marine readers have rated Mercury MerCruiser Bravo Outdrives Sterndrives Marine Engines Service Manual Number 28 3.0 out of 3.0 based on 1 product reviews. I could not find any mention of the seawater pump assembly.
Maybe I have the wrong unit