As Bubble is a 2003 model (Bavaria 32) and I had some time on my hands, I decided to remove the elbow. I was shocked to see how much the diameter of the water injection hole on top of the elbow had been restricted due to build-up of something hard, like calcium in a kettle. I have a photo which would frighten anyone with a similar elbow and boat of the same vintage, but it looks like I can’t upload it using this new system.
As I was installing a new elbow I felt up into the rubber seal which brings cooling water from the heat-exchanger to the exhaust and lodged in that was calcium ‘washer’ restricting about 3/4 of the water flow. I nearly missed that.
I had the original Volvo water-trap in the exhaust and it looked fine but I’ve noticed a small amount of brown seawater under the trap so I’ve replaced it with a new Vetus plastic model. If it is no good the Volvo ones are still available, but I don’t like the design.
I had a B34 (2002) and had the same thing. Interestingly though, I also had that ‘washer’, and believed it was a part of the elbow which had came away when I pulled the hose off.
Yes, amazing how they corrode, I changed mine to a SS one, I sold the boat a year later so I don’t know how its holding up compared to the OE Volvo one. Even more scary, I left it in the shed at home, as you do! and a number of months later I came across it and it had literally split its self in half!
I also changed the Volvo water trap/silencer because of corrosion but put an original back on.