At the end of last season my trim tabs ceased operation and I found fluid in the bilge. I was waiting to re-install my batteries before tinkering with them but decided yesterday to tear the pump out.
My observations (based on limited knowledge) are as follows:
The pumping/control mechanisms are housed under the upper red cover.
The fluid is contained in the white/opaque plastic reservoir below.
The two appear to be connected via a thin metal tube.
My tube appears to have broken. Replacement of this tube and possibly some connecting hardware would not, on the face of it, seem like a big deal for an amateur.
I've found the Boat Leveler site along with a long list of parts. As always I'm tempted just to buy a new motor pump unit at $300 and dump the broken unit on ebay to defray the cost. Finally my question, anyone have any experience or knowledge of this repair?
Actually it cleaned up remarkably well with Castrol GTX, CX and Blue cleaner.
Still, I was force to drill out the remnants of the broken fluid tube which might make the new tube leak, or may have messed up the pump beyond.
I may have fried something trying to run it off a battery in my garage too.
Better than 50% chance I'll end up w/ a whole new "red box".......$310....
BTW, the folks at Insta-Trim have been very helpful over the phone.
I used to work for Bennett trim tabs and can help a little with how the system works.
If you ground the motor and put 12V directly to one of the wires going into the motor and the motor does not turn, it'd dead.
The Insta-Trim pump uses a reversing motor to put the tabs either up (motor forward) or down (motor reverse) The unit has a common ground and two positive wires going to the motor, the switch at the helm energizes one or the other.
At the same time the motor is turning one or both of the solenoids is energized to open and direct fluid either port, stbd or both.
Contrary to popular belief when running in reverse (to retract) the pump is not "pulling" the tabs up but there is a "return" spring in the actuator that does most of the work of "pushing the tabs up.
Bennett and Insta-Trim pumps are interchangable with minor modifications. You would need a pump bracket and to change the compression fittings for tube to hose nipples for hose to use a Bennett pump on a Insta-Trim system. You would also need the color cross reference for the wiring, both use a 4 wire harness.
Hope this is helpful, I always find it useful to know how and why things work on my boat.
