Raw water flush problem, 8V71TI's

[dar636]

Hello,

So I was planning to do a raw water flush, a variation of the procedure described by Genesis and had the following problems. I was trying to do a complete system flush vs. just isolating the HE and intercoolers, running the cleaning solution backwards to normal flow (this is on my 8V71TI's in a '76 Yachtfisherman). I don't have a cooling problem, just trying to baseline my maintenance status.


I hope this is clear, I don't have any pictures...

I have a 5 gallon bucket, 500 gpm bilge pump, hoses, fittings etc and was using Ospho.

I closed the seacock on the test engine, broke into the 2" raw water line on the outlet side of the HE (Stbd side of engine) for the bilge pump outflow (solution IN) - and put the return hose to the bucket in the zinc fitting position on top of the raw water pump, which is the pumps exit side. After trials and closing up the small valve for the PSS seals, I was able to fill the test engine with water using the bilge pump in the bucket and have it hold a steady quantity in the bucket but was not getting any solution flow through the engine. If I opened the source line for the PSS seals, the water in the bucket would immediately start dumping overboard thru the shaft seal.

I am assuming that the raw water pump impeller is what is blocking the flow of cleaning solution. For an alternate return line location I could break into the raw water exit tube from the last intercooler - ahead of the raw water pump but ran out of time yesterday.

My question is: For those that have done complete system flushes on 871's , where do you install the fittings for the solution IN and RETURN? Pictures?

[racclarkson@gmail.com]

Hello,So I was planning to do a raw water flush, a variation of the procedure described by Genesis and had the following problems. I was trying to do a complete system flush vs. just isolating the HE and intercoolers, running the cleaning solution backwards to normal flow (this is on my 8V71TI's in a '76 Yachtfisherman). I don't have a cooling problem, just trying to baseline my maintenance status. I hope this is clear, I don't have any pictures...I have a 5 gallon bucket, 500 gpm bilge pump, hoses, fittings etc and was using Ospho.I closed the seacock on the test engine, broke into the 2" raw water line on the outlet side of the HE (Stbd side of engine) for the bilge pump outflow (solution IN) - and put the return hose to the bucket in the zinc fitting position on top of the raw water pump, which is the pumps exit side. After trials and closing up the small valve for the PSS seals, I was able to fill the test engine with water using the bilge pump in the bucket and have it hold a steady quantity in the bucket but was not getting any solution flow through the engine. If I opened the source line for the PSS seals, the water in the bucket would immediately start dumping overboard thru the shaft seal.I am assuming that the raw water pump impeller is what is blocking the flow of cleaning solution. For an alternate return line location I could break into the raw water exit tube from the last intercooler - ahead of the raw water pump but ran out of time yesterday.My question is: For those that have done complete system flushes on 871's , where do you install the fittings for the solution IN and RETURN? Pictures?

Remove the impeller. Any solution that gets to sea cock will clean it too. Or hook into transmission cooling circuit which is above impeller.