Coolant leak R25 SC D3

[portlandtug25]

Hello,
As per my posting earlier this month, I'm experiencing very slow leak ( lost about 8 oz after a 9 hour cruise) at the brass elbow on the heater hose right by the oil dipstick. Another D3 owner with the same issue told me that the problem turned out to be a missing washer in the elbow connection in his case. On my boat the hose clamp on the outflow side of the elbow seems tight and not the source of the leak, so I suspect it is the same problem, ( and I've shut both heater hose valves )


So here are my questions:
1.If indeed, in my case also, it is a missing washer, is that something that requires a specific Volvo part and mechanic to fix, or is it a part that any good boat mechanic could replace?

2. If I don't fix it right away, is it likely that it is going to get drastically worse suddenly?

3. Is there a way to block or cut off the coolant flow to this elbow, so that a complete drain of the cooling system isn't necessary to R/R? I've got the valves to the hot water heater and the cabin heater both closed.

3. Why would it not leak at all for the first 240 hours of operation ( the boat has 249 hours on it) and then start leaking?

Thanks! Any help would be appreciated soon since I'm planning an early September cruise.

Roger Friedel in Portland

 

[dclagett]

I believe the answer to your first question is: it is not a Volvo part. This is an accessory for supplying coolant to the heaters and was put on by the RT factory. I would guess that Volvo provides the port for both coolant feed and return, which is plugged by Volvo. The boat manufactures utilize these ports to provide their accessories.

In order to block coolant flow to the elbow I would take the feed hose from the engine off the elbow and put a plug in it. It is a pain to get to it, but I would think this would be your simplest approach. You can either use a pinch hose clamp so you don't loose coolant or be quick with a plug when you pull the hose off the elbow.

Hope this helps... Dick

 

[TBates]

Hi Roger,

The hot water valves/nipples are in fact a Volvo provided part, that are installed once the engine arrives, but before it enters production. If you can please email a picture, I'll verify that you have the correct part installed. A good mechanic should be able to address the replacement (if necessary) without too much difficulty. To avoid coolant loss I would close the valve, and use a tool similar to the one shown in the link I've attached to prevent coolant from leaving the engine.

https://www.amazon.com/GearWrench-3..._rd_t=40701&psc=1&refRID=2VMKG6DJ5F23DFJ32HW2

You can also try tightening the fitting itself if you haven't already done so. Depending on the age of the engine, it might be a good time to perform a coolant change as it's recommended service interval is every 48 months.

Thank you,

-Tim

 

[bchristie]

I am a new Cutwater 26 owner so learning the boat. I have the same coolant leak on my D3 engine at the brass elbow fitting near the oil dipstick on the coolant line from engine to water heater. The leak is at the threaded connection and not at the hose clamp connection. I have tried to tightened this fitting but it is is very tight and did not turn more when forced applied. Any help will be greatly appreciated.

 

[dclagett]

In my case the threaded connection leak was caused by using pipe thread sealant on a non pipe thread connection. The connection requires an O-ring. Once the appropriate O-ring was installed the leak stopped. This appears to be a problem with several D3 installations.