NorthernFocus
Well-known member
- Joined
- Jun 29, 2014
- Messages
- 1,376
- Location
- Alaska
- Website
- www.northernfocusphotography.com
- Fluid Motion Model
- R-25 Classic
- Hull Identification Number
- FMLT25910808
- Vessel Name
- Divine Focus
The first cautionary side of the tale is to exercise good seamanship and don't rely too much on instrumentation. Modern engines have so many alarms etc. that one can rely too heavily on them to protect against anything that can go wrong with the equipment. At least on the Cummins equipped boats, one big hole in the array of protective devices is that there isn't anything monitoring the condition of the transmission.
We recently made a week long trip on Prince William Sound. At the end of day one, 41nm transited, I checked the engine compartment and found a bit of oil sprayed around the aft part of the drive train. It was obviously not engine oil nor diesel. I quickly found a small leak from one of the hydraulic hose fittings on top of the transmission. The oil had dripped onto the coupling and been flung around. The fitting wasn't loose and I couldn't determine exactly where the fitting was leaking. With no parts and no sure determination of where the leak was, there wasn't much to do about it. So I wrapped a piece of absorbent (maybe 1/8 of a pad) around it and fastened it with a wire tie and just had to keep an eye on it.
On day two we transited another 23nm. Periodic checks showed the small leak had continued but was easily captured by the absorbent pad. When we reached our anchorage I removed the pad and it had a fair bit of oil in it but wasn't saturated and hadn't dripped at all. So I replace it with a new piece of absorbent the same size. The next day we only had 16nm to run and we'd be in Valdez where we could hopefully replace the hose.
When we arrived in Valdez, the absorbent material was completely soaked this time. The leak was obviously getting worse. I removed the hose and took it to the only shop in town that could make up a hose. Unfortunately they didn't have the necessary metric fittings.
Well at this point we were 350 road miles from the nearest shop likely to have what we needed plus had no vehicle to get there. So I decided to reinstall the hose and try to figure out exactly where it was leaking. We worked our way out of the harbor at 1200 rpm or less and stopped to take a look. I was able to identify the point at which the oil was coming out under the pressed on nut retainer. We fired back up and headed back to the dock, maybe half a mile total, most of which was at idle inside the marina.
Back in the slip I opened the hatch and was shocked. In that short run the leak had deteriorated so badly that the compartment was covered in oil and there was a good level of it in the bilge sump. So much so that I was concerned about transmission damage. Had the leak deteriorated to this point on our way into port the previous day, we likely would have trashed the transmission. No warning devices protect against low transmission oil level, pressure, high temp, etc.
There is a part two of the cautionary tale. After purchasing the boat I made up a substantial do-list of fixes, upgrades, etc. One of the things that caught my attention were the hoses on the transmission. For one thing they were obviously not original as the zinc metal was still bright. So they had been replaced at least once for some reason. Secondly, they were a poor choice of materials for use in a service subject to a lot of vibration like an engine. So replacing the hoses with a different more reliable design was on my list but I just hadn't gotten to it yet. So shame on me for not making it a higher priority.
I don't know if these hoses are per the original design or if they were after market. But if anyone has hoses like the one in the following photos, I highly recommend replacing them.
Pic 1: The subject hose.
Pic 2(sorry for image quality): Location of the failure. Note the leak did not occur in the typical place. It was not leaking from under the threaded nut. It was leaking under the nut retainer. The retainer is pressed onto the steel tubing which causes a stress riser in the steel. This type of stress riser is particularly susceptible to damage when subjected to vibration.
Pic 3: Old(top) versus new(bottom) hose style.
We recently made a week long trip on Prince William Sound. At the end of day one, 41nm transited, I checked the engine compartment and found a bit of oil sprayed around the aft part of the drive train. It was obviously not engine oil nor diesel. I quickly found a small leak from one of the hydraulic hose fittings on top of the transmission. The oil had dripped onto the coupling and been flung around. The fitting wasn't loose and I couldn't determine exactly where the fitting was leaking. With no parts and no sure determination of where the leak was, there wasn't much to do about it. So I wrapped a piece of absorbent (maybe 1/8 of a pad) around it and fastened it with a wire tie and just had to keep an eye on it.
On day two we transited another 23nm. Periodic checks showed the small leak had continued but was easily captured by the absorbent pad. When we reached our anchorage I removed the pad and it had a fair bit of oil in it but wasn't saturated and hadn't dripped at all. So I replace it with a new piece of absorbent the same size. The next day we only had 16nm to run and we'd be in Valdez where we could hopefully replace the hose.
When we arrived in Valdez, the absorbent material was completely soaked this time. The leak was obviously getting worse. I removed the hose and took it to the only shop in town that could make up a hose. Unfortunately they didn't have the necessary metric fittings.
Well at this point we were 350 road miles from the nearest shop likely to have what we needed plus had no vehicle to get there. So I decided to reinstall the hose and try to figure out exactly where it was leaking. We worked our way out of the harbor at 1200 rpm or less and stopped to take a look. I was able to identify the point at which the oil was coming out under the pressed on nut retainer. We fired back up and headed back to the dock, maybe half a mile total, most of which was at idle inside the marina.
Back in the slip I opened the hatch and was shocked. In that short run the leak had deteriorated so badly that the compartment was covered in oil and there was a good level of it in the bilge sump. So much so that I was concerned about transmission damage. Had the leak deteriorated to this point on our way into port the previous day, we likely would have trashed the transmission. No warning devices protect against low transmission oil level, pressure, high temp, etc.
There is a part two of the cautionary tale. After purchasing the boat I made up a substantial do-list of fixes, upgrades, etc. One of the things that caught my attention were the hoses on the transmission. For one thing they were obviously not original as the zinc metal was still bright. So they had been replaced at least once for some reason. Secondly, they were a poor choice of materials for use in a service subject to a lot of vibration like an engine. So replacing the hoses with a different more reliable design was on my list but I just hadn't gotten to it yet. So shame on me for not making it a higher priority.
I don't know if these hoses are per the original design or if they were after market. But if anyone has hoses like the one in the following photos, I highly recommend replacing them.
Pic 1: The subject hose.
Pic 2(sorry for image quality): Location of the failure. Note the leak did not occur in the typical place. It was not leaking from under the threaded nut. It was leaking under the nut retainer. The retainer is pressed onto the steel tubing which causes a stress riser in the steel. This type of stress riser is particularly susceptible to damage when subjected to vibration.
Pic 3: Old(top) versus new(bottom) hose style.