General Precautions - TOHATSU 40 Service Manual

SECTION 8

GENERAL PRECAUTIONS

Before performing any service work on the power trim/tilt system,
read and understand the Service Safety section at the beginning of
this manual.
Pressurized hydraulic oil in the PT/T unit can cause serious injury.
Always wear safety glasses and skin protection when servicing the
system.
Before disassembly, always depressurize the PT/T unit as follows:
• Fully extend the tilt cylinder rod and engage the tilt stopper.
• Open the manual valve in increments.
• Allow PT/T unitto fully depressurize.
Do not fully open the manual valve when the engine is tilted down.
Oil pressure is at its highest when engine is in this position.
Never apply heat to the PT/T manifold or cylinder body. Heat can
cause high pressure leaks and failure of parts.
If manual valve is opened for manual tilting, engine cannot be held
in the UP position by closing the manual valve. Engine must be
safely supported using the tilt stopper or a suitable trailering
bracket or hoist.
Significant residual pressure can exist behind components when
removed. Always cover each part with a shop rag when removing it.
Replace locking fasteners when their locking feature becomes
weak. Once removed, always install new snap rings. Use only
factory replacement parts.
When using compressed air to clean or dry parts, make sure air
supply is regulated not to exceed 25 psi [172 kPa / 1.76 kg/cm
Before returning the engine to customer:
• Make sure the manual valve is torqued to specification.
• Make sure the thrust rod is installed in its original location.
Leaving the rod out or moving it closer to the boat will allow the
engine to trim in farther than expected by the customer and
could result in loss of control.
Serial Number Breakpoints
Reference is made to differences between old and new Style Power
Trim and Tilt Units (PT/T). The following Serial Numbers indicate
breakpoints between older and newer Power Trim and Tilt models:
8-2
].
2
HP
60 B
60 C
70 B
70 C
90
115/120
140
New Style PT/T
11646 or higher
10001 or higher
23401 - 23413,
23439 or higher
10001 or higher
22313 - 22342,
22348 - 22358,
22365 or higher
21739 or higher
12174 or higher
3-/ 4-Cylinder