Mysterious leak

[rappja]

I have a 2019 RT-32CB LE.
There has been a persistant leak since I bought the boat 7 months ago. Hard to tell weather it is salt or fresh, as we are on a mostly fresh estuary.
I discovered what looks like a thru-hull sensor that is leaking. I posted pictures. It is located on the starboard hull, just below the stove, and forward of the hot water heater. You can se it behind the hot and cold water lines. It looks like it was sealed (in a messy fashion) and is leaking from the sealant.
I thought the boat came with a hull mounted transducer for the sonar, so I don't know what this is.
Any thoughts on this? Am I right about the hull mounted sonar (which I believe is below the salon reefer, which I have to remove to get to that area. I don't want to do that yet.

 

[Cutwater28GG]

if I'm not mistaken, that looks like the standard transducer that's glued onto the hull and doesn't go through the hull. They are supposed to be installed with a cup that contains liquid to provide a solid audio connection to the hull. For most of the installs on Ranger and Cutwaters, they just glued the transducer part directly to the hull with Sikaflex 4200.

The liquid could be antifreeze or oil. two typical liquids used to provide the connection. most people use the pink antifreeze.
if it is a cup install, two things can happen:
the glue has failed and its leaking
the gasket (known to be useless) between the cup and transducer can leak when the boat bounces in waves.

if it's installed in a cup, you can rotate and pull up the transducer, and it should unplug from the cup. You should find a cup with a little liquid.

If it's using antifreeze this is the perfect source to create mold - black, which is what the leak looks like from the photos

if it's just glued on without the cup, the liquid is coming from somewhere else.


Now, I could be completely wrong, and that's a through-hull sensor. some of those protrude from the hull. you can have trouble with them resting on trailer bunks. That might have caused the installation to fail and cause a leak.

 

[venajeff]

My transducer also had a leak. Pink antifreeze. I removed it and sanded down the surface with some 120 grit and reapplied it with 100% silicone. I researched online on the best product to use and couldn't get a definitive answer, but did see many people having similar leaking issues so I determined that perhaps the common adhesive to install them might not be the best, so I used my own judgement. So far it has not leaked in 12+ months.
Also I noticed that your hot water tank is above this area. Check the fittings on that for any leaks. Ours has a slow leak on the lower fitting. Had to remove it and add Teflon tape to fix it.
I hope you have luck finding your leak. I am a little compulsive about having clean dry bildges so I feel your pain.

 

[Pandion]

Your photos appear to show a Garmin GT15 in-hull transducer mounted in a cup. If it were a thru-hull there would be threads on the transducer body.

As Cutwater28GG and venajeff have stated, they're known to leak where the cup is glued to the hull. It looks like maybe someone tried to seal a leak around the base without actually removing the cup from the hull, which would be unlikely to work long-term.

The older Airmar transducers could be separated from the cup by just twisting it, but with the Garmin you have, you'll need to unscrew the six screws on top of the transducer to pull it out of the cup. Those cups only hold a few ounces of liquid, so I agree with venajeff that if you're seeing a persistent leak over many months that looks like water, you probably have another leak somewhere.

 

[rappja]

Your photos appear to show a Garmin GT15 in-hull transducer mounted in a cup. If it were a thru-hull there would be threads on the transducer body.

As Cutwater28GG and venajeff have stated, they're known to leak where the cup is glued to the hull. It looks like maybe someone tried to seal a leak around the base without actually removing the cup from the hull, which would be unlikely to work long-term.

The older Airmar transducers could be separated from the cup by just twisting it, but with the Garmin you have, you'll need to unscrew the six screws on top of the transducer to pull it out of the cup. Those cups only hold a few ounces of liquid, so I agree with venajeff that if you're seeing a persistent leak over many months that looks like water, you probably have another leak somewhere.

I looked at photos of the device on-line, and yes, I believe it is a Garmin GT15. I now don't think it is the source of the leak. Each time the bilge pump goes on (about every 3 or 4 minutes), it discharges a few ounces of water. By now, I would think the transponder cup would be empty, and the depth sounder wouldn't work.

 

[Cutwater28GG]

the water is likely coming from the stuffing box. they drip by design.
That being said, I would go hunting for other leaks,

i would take the transducer off to have a look anyway.

 

[rappja]

the water is likely coming from the stuffing box. they drip by design.
That being said, I would go hunting for other leaks,

i would take the transducer off to have a look anyway.

Checked the stuffy block. It's wet but not actively dripping.

 

[Kgcmflyer]

Checked the stuffy block. It's wet but not actively dripping.

Check the hot water “pop off” valve…(pressure relief valve)…by design they vent to control pressure…may just be running from HW heater to “low spot” at transducer.
I assembled a tube and catch box for mine and just empty as needed. Keeps that water out of bilge for better diagnosis if water is found in bilge.

 

[rappja]

Great idea. I'll check it.
Would there still be a leak if I emptied the water tank, which I did?
Thanks

 

[rappja]

the water is likely coming from the stuffing box. they drip by design.
That being said, I would go hunting for other leaks,

i would take the transducer off to have a look anyway.

BTW, should the stuffing box be actively dripping when the prop shaft isn't turning?

 

[gswearin]

The stuffiness box shouldn’t drip but mine does no matter how often I tighten it. Only a drop it two a minute. I’ll have it looked at eventually.

 

[Mastercraft]

I have a 2017 R29 and I thought the shaft was designed to drip. Is it really no drip design? If drip design, what is acceptable drip rate?

 

[sgeary]

There is a good Ranger Tugs video on overall maintenance and desired tools to have at the link below. The section on proper adjustment of the packing gland is at 16:31 of the video.
If you cannot maintain the proper drip rate when underway, then consider having your shaft alignment checked.

 

[gregc]

My transducer properly detached from the hull shortly after I bought it in '20. Had to re-glue the entire transducer body to the hull. It was easy to know if it was sealed properly b/c the pink anti-freeze would leak into the bilge.

 

[Jcat2010]

Have you checked all the hot water connections? I've found that the heater can move a bit and sometime stress a connection and they leak just a bit but constantly.