No Signs of a leak

[KC WV]

I installed new Bennett trim tabs last spring. I'll never own another boat without them! This season, I noticed that they didn't seem to be engaging all the way down, so i checked the pump reservoir. It was low. So i added fluid. I bled the system during installation as described in the instructions.

Recently, I rechecked, and the fluid level has fallen about a half inch. I'm sure the tabs are fully retracted to the bow up position before checking. Also, there is absolutely no sign of leaking inside or outside of the boat. I've checked all the fittings, lines, pump area under the cover, on top of the reservoir, behind reservoir, and actuators. I cant find any apparent leaks. I added more fluid and exercised from full up and down about 10 times. The fluid level remain unchanged.

Could this possibly be air still working out of the system, or something else?

 

[Tabman]

KC,

It may have been a little air in the system, but I would like you to run both Trim Tabs all the way down and leave them there overnight.

If there is a leak one or both Trim Tabs will retract on their own. Try this and let me know the results.

Tom
Bennett Marine

 

[KC WV]

OK. Just put em down for the night. I'll check them tomorrow and let you know. thanks for the tip.

 

[KC WV]

There was very little if any retraction overnight. It was almost 21 hours that they were untouched in the full bow down position. I measured the inner shafts so I can recheck tomorrow to see if there is any movement at all. I did recheck for leaks despite no sign of retraction, and couldn't see anything. I checked the lines, tubes coming through the transom, and actuators, but did not remove the cover to check the pump.

 

[Tabman]

Ok, so far so good. If they stayed down like that I doubt there is a leak in in the lines or actuators. The only other place would be in the pump itself specifically where the motor shaft enters the pump body. A leak there would only occur when the pump was running and you see the fluid dripping off the reservoir.

I would suggest just running the boat and check the fluid level from time to time.

Tom
Bennett Marine

 

[KC WV]

That sounds good. Thanks for your help. If it does get worse, or I start loosing more fluid, I'll start over with this and get back with you. Thanks again Tom.

 

[KC WV]

OK, time to revisit this thread. I've had to add fluid a couple of times, so this year, i've placed small towels around all the connections and under the pump. Lost fluid, and all the towels were still dry. so last Saturday, i ran them all the way down as you suggested. I haven't used the boat since. Today, i found that the stbd tab retracted almost all the way up on it's own. Any suggestions?

 

[Tabman]

KC,

I am assuming that the boat is out of the water and there was no evidence of fluid leaking from the starboard actuator? Is this the case?

Thanks
Tom
Bennett Marine

 

[KC WV]

that's funny, after i posted that last night, i thought to go out and check for any signs of leakage. the boat is out of the water, and i saw no signs of leakage on the outside actuator. where could that fluid be going?

 

[Tabman]

KC it is funny,

Two things,

Do you remember when you installed them if they had pipe nipples that went through the transom with a female elbow attached inside? If so some fluid mag be leaking where the nipple screws into the top part of the actuator and is leaking inside the transom.

Also are you sure you lost fluid? If one of the valve seats was leaking the fluid would escape back into the reservoir and the tab would retract. To test this you can swap the hydraulic lines at the pump and see if the problem changes sides.

Tom
Bennett Marine

 

[KC WV]

Definitely loosing fluid. I will look closer at the connection at the pipe nipple for a leak. the hardware you described above, with the pipe nipple and female elbow is exactly what I have. It's definitely a slow leak, usually just have to add a few oz of fluid about every 30 hours of operation. I do use those tabs frequently. Thanks for your help.

 

[Tabman]

Let me know what you find. If we think the leak is there I can send you the parts to fix it, no charge.

Tom
Bennett Marine