4588 - How to fill the trim tab reservoir?-gctid405470

[Foster]

The trim tab reservoir on my 1993 4588 is empty. (Could be why I can't trim it to get up on plane). Mine is mounted on the stern, in the starboard hatch, near the drain lines for the deck.

I pulled the smoked plastic top off (it's held on by 1 screw. There does not seem to be a fill cap. There is a little cap on the left front that pulls out. It has a long stem on it. I though that it was the fill (pretty tiny) but it only took about 5 drops of transmission fluid to fill the space.

Any hints on how to refill the reservoir?

[SuperiorDiver]

Look at http://www.baylinerownersclub.org/fo...-Tab-reservior, from 2008.

Or, http://www.bennetttrimtabs.com/image...illing_big.jpg and http://www.bennetttrimtabs.com/faqs.php?tID=3#num7.

[Foster]

*smack* Search the older threads before posting Foster *smack*

Thanks for the links. I was able to borrow for a few moments a screw cap with a long length of 1/8" tubing, the perfect size to go in the hole.

So I squeezed in some ATF (as specified) and found that the reservoir is actually full. But it appears it's full of a thin weight oil, not ATF.

Is this going to be a problem?

Is reservoir being almost 90% full a problem? (I thought it was empty, since there was no "line of fluid", but it's full to the top.

[mmichellich]

Get one of those ketchup containers that some restaurants use, those red containers with the small spout.

[Tabman]

Use any type of Automatic Transmission Fluid (ATF). Don't worry about the exact brand or type - it will all work, and can even be mixed. To add fluid, remove the Lexan cover on the HPU, locate the "filler stack" in the left front corner of the reservoir. There is a round plug sealing the filler stack. Remove the plug and add fluid to the full line on the reservoir. Note: Add fluid only with the trim tabs fully retracted (up). If your reservoir does not have a full line, add fluid so the fluid level is about 1 inch below the top of the reservoir with the trim tabs fully retracted (up). This is important since the fluid will be in the cylinders when they are down.

Also a small funnel is helpful, I like the filler spout shown in the picture, if you (or anybody else) would like one, just send me your name and address in a private message and I will send you one, no charge.

It may help to know that the pump can be slid out of the bracket that holds it to the bulkhead. Just push up from the bottom about an inch and you can remove it. Sometimes this makes filling a little easier.

If the reservoir is discolored and you can't see through it, you can use something like a pipe-cleaner as a dipstick.

If it is overfull it may overflow when the Tabs are all the way up.

Using a fluid other than ATF can damage the seals in the system.

Can you tell if the Trim Tabs are moving? If the boat is in the water sometimes you can use a boat hook to measure their movement.

Tom McGow

Bennett Marine

Tom McGow

Bennett Marine

[Foster]

Trim tabs are moving, I'm able to trim the boat both bow up and bow down. Thanks for the help!