Hino 150 Salt Water Flushing-gctid347180

[Guest]

Need advice on how to flush my Salt Water Cooling systtems. Have a 1991 3288 with twin Hino 150 turbo's. What are the procedures for "Immersion Cleaning"? What about "Open Loop Recirculation? Has anyone used the TRAC Marine Product "Barnacle Buster"? How about using CLR? HELP!

[Dave_Stevens]

I have installed a fresh water flushing system on my last 3 boats. This works well if you DO NOT have water lift mufflers. Install a "T" fitting between the raw water seacock and the sea strainer. Then put a bronze 3/4 valve into the "T" and connect the lines from the valves to a fresh water source with a shut off valve. I connected to the domestic cold water. If you have a dockside hose bib for fresh water, attache the hose, turn off your domestic water pump, close the sea cocks and open the valves. Fresh water then flushes through the raw water pump, heat exchangers and exits by gravity through the exhaust. This system does not work with most gensets as they have water lift mufflers and you risk water getting into the cylinders.

[Guest]

Thanks Dave,

Do you remove your impellers, or does the water pressure just force itself past the rubber impeller?

[Dave_Stevens]

Water will flow past impellers on Hino raw water pumps (Johnson?) with little restriction. I flush for 30 minutes or so when we are back in port and unloading etc.

[mmichellich]

What are we saving by doing this flushing of the raw water system. Aren't all the raw water parts made to be in salt water. Doesn't the fresh water freeze at higher temps than salt water? I used to flush out a raw water cooled Chevy V-8, but it was not designed for salt water use.

[Guest]

Dave Stevens wrote:
I have installed a fresh water flushing system on my last 3 boats. This works well if you DO NOT have water lift mufflers. Install a "T" fitting between the raw water seacock and the sea strainer. Then put a bronze 3/4 valve into the "T" and connect the lines from the valves to a fresh water source with a shut off valve. I connected to the domestic cold water. If you have a dockside hose bib for fresh water, attache the hose, turn off your domestic water pump, close the sea cocks and open the valves. Fresh water then flushes through the raw water pump, heat exchangers and exits by gravity through the exhaust. This system does not work with most gensets as they have water lift mufflers and you risk water getting into the cylinders.

Dave

The way I do my genset is that I've put a hose fitting into the brass top of the strainer. I hook a hose up and turn it on, but not at high pressure. Start the genset and while its running, slowly open the petcock for the hose fitting, so I'm running both fresh and salt water. Then close the seacock so I'm just on fresh water. After running for a few minutes, I shut off the fresh water and have Leila shut off the generator. Since I never have hose pressure without the engine running, it avoids the water in cylinder problems. I also put salt away in the fresh water as I'm doing it. Seems to work fine. I think the trick is just to make sure you're not running fresh water under pressure into fitting with the gen not running.

[Dave_Stevens]

courtjeste wrote:
Dave

The way I do my genset is that I've put a hose fitting into the brass top of the strainer. I hook a hose up and turn it on, but not at high pressure. Start the genset and while its running, slowly open the petcock for the hose fitting, so I'm running both fresh and salt water. Then close the seacock so I'm just on fresh water. After running for a few minutes, I shut off the fresh water and have Leila shut off the generator. Since I never have hose pressure without the engine running, it avoids the water in cylinder problems. I also put salt away in the fresh water as I'm doing it. Seems to work fine. I think the trick is just to make sure you're not running fresh water under pressure into fitting with the gen not running.

I do the same for the genset but it is a little complicated if you don't know what exactly is going on. Also, there is the danger of burning out the impeller if it runs dry, even for a few seconds.

The benefit of fresh water flushing is that initially hot salt water is not setting in the heat exchanger and risers when the boat is idle for a few days or weeks. Salt water is an electrolyte which really promotes corrosion in cast iron risers and Al manifolds.

[smitty477]

There are a number of advantages to fresh water flushing Hino's and gensets so the message that follows is not intended to dispute that overall statement.

FWIW - if your raw water exhaust drain hose is kept open the water will never sit in the riser areas after running on any of these engines.

Additionally - for those of us that have converted to SS or Cu Ni risers the effects are much less agressive especially if they are ceramic coated.

Hope this helps

[Dave_Stevens]

I had thought of leaving the drains open but where would you drain them. I hesitate to add another line to the shaft log that is a below the waterline fitting and do not want to discharge it into the bilge which is dry.

[smitty477]

Hi Dave,

"I had thought of leaving the drains open but where would you drain them."

If you follow the small hose at the top of your propshaft logs it will end up at the elbows. They are really used to lubricate the packing but they also facilitate draining the water from elbows if they are kept open. FWIW - for those of us who have looked into the cooling bundle area often it becomes clear that the water level drops pretty low between uses (below end caps). And also that the materials that the raw water is in contact with are never aluminum in construction.

Hope this helps

[Guest]

smitty477 wrote:
Hi Dave,

"I had thought of leaving the drains open but where would you drain them."

If you follow the small hose at the top of your propshaft logs it will end up at the elbows. They are really used to lubricate the packing but they also facilitate draining the water from elbows if they are kept open. FWIW - for those of us who have looked into the cooling bundle area often it becomes clear that the water level drops pretty low between uses (below end caps). And also that the materials that the raw water is in contact with are never aluminum in construction.

Hope this helps

This brings up a very good point if you are running the original cast risers with the cast elbow in the hose you need to take it loose occasionly and claen it out. There is a pit **** on the elbow that I bet most people have never opened. When I replaced my cast risers with stainless the elbows were almost completly blocked, and I would bet there was no water making it to the packing gland.

[mmichellich]

NWCruiser wrote:
This brings up a very good point if you are running the original cast risers with the cast elbow in the hose you need to take it loose occasionly and claen it out. There is a pit **** on the elbow that I bet most people have never opened. When I replaced my cast risers with stainless the elbows were almost completly blocked, and I would bet there was no water making it to the packing gland.

What is a pit ****?

[Guest]

The site edited the word, it is the drain on the bottom of the elbow with the T handle that screws in and out just like on a radiator.

[mmichellich]

NWCruiser wrote:
The site edited the word, it is the drain on the bottom of the elbow with the T handle that screws in and out just like on a radiator.

OK, thanks