Nick F
Guru
- Joined
- Sep 2, 2020
- Messages
- 688
- Location
- Canada
- Vessel Name
- Callisto
- Vessel Make
- 1974 Grand Banks 42 Classic, Hull 433
I am hoping that a fellow Grand Banks owner can give me some information about the heat exchanger (hex) on these early engines.
Due to a minor leak at one of the raw water connections, I decided to open up the hex. I discovered that the inside is quite heavily scaled (photo shows the least scaled example) and so I need to soak it in some scale dissolver (I will start with vinegar).
Descaling would best be done off the engine and here is where the problem starts. The hex is buried below the coolant header tank and appears very difficult to remove. In fact, I could remove it by cutting the coolant hoses but the problem is - how to re-install the hex. Can anyone give some tips on removal?
The removal/reinstallation looks so bad that I am considering removing the hex and then mounting it on the side of the engine (in a fore/aft orientation). This way it would also be more accessible for future maintenance.
Another detail I am wrestling with is the rubber seal washers for where the tie-rods come through the end plates. There is a conical rubber washer that is supposed to make a seal on the threaded rod tie-rod (see photos). Has anyone replaced these seals? I looked at a local GB42 that has the same engines and its hex´s have had their end caps brazed on, so no help there !
Yet another detail: I may have to remove the exhaust elbow and possibly the coolant header tank. These are Ammarine parts, not JD. Has anyone managed to buy gaskets for these? (see photo)
Regards,
Nick
Due to a minor leak at one of the raw water connections, I decided to open up the hex. I discovered that the inside is quite heavily scaled (photo shows the least scaled example) and so I need to soak it in some scale dissolver (I will start with vinegar).
Descaling would best be done off the engine and here is where the problem starts. The hex is buried below the coolant header tank and appears very difficult to remove. In fact, I could remove it by cutting the coolant hoses but the problem is - how to re-install the hex. Can anyone give some tips on removal?
The removal/reinstallation looks so bad that I am considering removing the hex and then mounting it on the side of the engine (in a fore/aft orientation). This way it would also be more accessible for future maintenance.
Another detail I am wrestling with is the rubber seal washers for where the tie-rods come through the end plates. There is a conical rubber washer that is supposed to make a seal on the threaded rod tie-rod (see photos). Has anyone replaced these seals? I looked at a local GB42 that has the same engines and its hex´s have had their end caps brazed on, so no help there !
Yet another detail: I may have to remove the exhaust elbow and possibly the coolant header tank. These are Ammarine parts, not JD. Has anyone managed to buy gaskets for these? (see photo)
Regards,
Nick
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