Garmin Auto Pilot Fluid

Cessna172

Well-known member
Joined
Apr 14, 2016
Messages
143
Fluid Motion Model
R-21 EC
Vessel Name
Nitro Fish
Anyone know what color the fluid is that used on the Garmin Auto Pilot systems? I have a 2017 C28.

I am finding a few (well probably more than a few : / ) drops of yellow fluid. It is accumulating nearly directly under the water heater plumbing and just forward of the Garmin valve system. Starboard cockpit access panel. Not sure if its diesel, pee, or Garmin fluid.

Your insight would be very much appreciated.

Gary
 
Could be antifreeze.

Stuart
 
Automaticman865":1ltaq2pc said:
Could be antifreeze.

Stuart

Good thought! Any idea how anti-freeze would end up under the water heater?
Gary
 
Gary,
you have a heat exchanger in the heater and I would check all the hoses. Your hot water will heat up from engine heat during normal running.

Stuart
 
Might consider smelling the fluid? That should at least rule out two of the three possibilities. The sterring fluid smells like hydraulic oil....the other two are kinda obvious. :shock:
 
Thanks for the replays. Yea, I tried smelling and feeling for "oiliness"; but, I cannot detect any smell and doesn't feel any slicker than water.

Is the Garmin fluid yellow?

Thanks,
Gary
 
The manufacturer's hydraulic fluid in the steering system is mostly clear out of the bottle, but I have had a few drops leak from my autopilot pump where the hoses enter and they do appear to be yellow, which I believe is the result of the thread sealer used upon manufacturing. Definitely has a oily feel to it.
 
Well that might be the case. The unusual thing is the "puddle" is located forward (20 inches) of the Garmin pump nearly directly below the water heater plumbing.

I am going to position a clean absorbent pad directly below the Garmin pump and water heater valves to try to determine the origin more accurately.
 
If the fluid does not feel slick like oil, then it is probably not oil (steering fluid). It would be easy to get antifreeze under the water heater on my boat. There is an antifreeze reserve tank located on the locker wall right next to the water heater. Any spill from this tank could collect under the heater. Take a look in the reserve tank to compare the spilled fluid with the antifreeze installed in your engine.
I truly hope there is not coolant hose leak as suggested as a possibility above. The heaters installed have changed over the years, but on my 2012 R27 the hose connections are on the forward end of the heater. Getting to these connections would be very difficult.

As an after note here, the hose connections to which I refer are the black rubber hoses which connect to the engine and the forward cabin heater. The fresh water hose connections are on the aft end.
 
Osprey":39qwk3wv said:
If the fluid does not feel slick like oil, then it is probably not oil (steering fluid). It would be easy to get antifreeze under the water heater on my boat. There is an antifreeze reserve tank located on the locker wall right next to the water heater. Any spill from this tank could collect under the heater. Take a look in the reserve tank to compare the spilled fluid with the antifreeze installed in your engine.
I truly hope there is not coolant hose leak as suggested as a possibility above. The heaters installed have changed over the years, but on my 2012 R27 the hose connections are on the forward end of the heater. Getting to these connections would be very difficult.

Seems that the configurations between the R27 and C28 are very different. The Volvo doesn't utilize a antifreeze recovery tank, the system is completely enclosed. Ironically, the Volvo antifreeze is the yellow variety. On the C28 the compartment that houses the water heater, inverter, Garmin pump, and a couple batteries is located under a starboard cockpit hatch. It seems to be relatively isolated from the engine compartment.
 
Automaticman865":2e3ntu1q said:
Gary,
you have a heat exchanger in the heater and I would check all the hoses. Your hot water will heat up from engine heat during normal running.

Stuart

Hi Stuart,

That is a very good possibility. I believe the heat exchanger hoses passing through this area are the black ones. Given the lack of diesel smell (I use mostly highway diesel - yellow) and the lack of oily feel. This may just be the culprit!

Thanks,
Gary
 
R27 -C28
Gary, after reading your last response I downloaded the C26-28 Users Manual. I note that the starboard cockpit lockers for the R27 - C28 have a slightly different component content, but are otherwise much the same. I found an interesting diagram on p.22 showing the coolant circuit from the engine to the water heater and the cabin heater. This diagram shows the coolant connections are on the aft end of the heater, hence easy to check. Further, there seems to be shutoff valves which, when closed, isolate the engine cooling circuit from the water and cabin heaters. Simply closing these values and going for a test run will indicate if you have or have not a leak at the water heater.
I am surprised that the Volvo engine does not have a reserve (expansion) tank. Your response and the C28 user manual both confirm that there is no tank. Water expands as it heats and I wonder how the Volvo system deals with this expansion. Does the pressure build up to the point that one springs a leak at hose connection locations?
 
Greetings Osprey,

Thanks for the detailed response. You're right. I checked the manual also and according to that the attachments are indeed on the aft portion of the tank. I live an hours' drive from the boat; so, I intend to check those fittings later this week. Additionally, Ronnie from Cutwater reached out to me and indicated that he believes these fittings also to be the leak source.

As far as the expansion tank, I too scratched my head over that one. But, search as I may, I cannot locate one. Fluid is added directly to the engine filler. I too would like to know the Volvo manages coolant expansion : /
 
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