575 sci Back Flushing Method - Need Advice
 

We run in the river 90% of the time, so sand/sediment/pebbles are part of it.

I've got low water pressure (4~6 psi), and I believe that my oil cooler is blocked.

On the 575, the oil cooler inlet and outlet face downward in the boat. I'm trying to figure out the best way to flush this cooler.

It's this style cooler....
http://www.boats.net/parts/search/Me...ne)/parts.html

Does this cooler have tubes that run the length like a 502 cooler? Is it worth the trouble (which looks like a b8tch) to remove the cooler and confirm if blockage?

I'm just not sure if this is an open cooler (which would allow small pebbles/sand to get through) or a capillary style - if open, then it's probably the next cooler in line. I hate to spend the hours removing the cooler if there is likely nothing blocking it.

Thanks for any help.

Just take off the water hose where water enters the oil cooler. You can reach your finger into the inlet and feel/remove any major debris. It has a screen with 1/8" holes.
If if you want to make sure its completely clear, just pull off both water hoses and run water backwards through the oil cooler.

Based on the waterflow diagram, water flows through the fuel cooler first. Is this an open cooler or does it have a screen/capillary tubes? Has anyone had one off that can answer?

Regarding the oil cooler, the inlet/outlet is from the bottom - very difficult to get to. Do the end caps come off? Do the end caps seal off oil or water or both?

Thanks for the advice.

OK. I got the cooler oil cooler off - what a MF'r !!

Anyway, for those who may be searching this later... the oil cooler has capillary tubes as I'd guessed. You have to remove the end caps to access the capillary tubes (or honeycomb grid). The end caps have rubber gaskets, so I just reused. We'll see how that works.

Unfortunately, I didn't find a whole lot of trash in my oil cooler. So, I'm still chasing a low water pressure issue...

check your fuel cooler

Does it have capillary tubes / honeycomb like the oil cooler?

Digging this thread back out as I didn't get a clear response last fall....

Does anyone know what the internals look like on the 575 fuel cooler? Is it an open chamber or tube / honeycomb grid style? Still chasing low water pressure. I just removed the oil cooler and power steering coolers and they are essentially clear. I did not find any debris in the hoses, either.

The fuel cooler is first in line after the sea pump. It is very difficult to reach - probably worse than the other 2 coolers. Is it worth the effort and my back to remove it and inspect? If it's a wide open style (no grid), then maybe not worth the time. But I've not been able to locate pictures of the input side to know what it looks like. The cooler has 90* elbows on each end, so getting my fingers in there has not been successful.

Any info would be appreciated.

Have you inspected the transom assembly and hose from transom inward for corrosion (if boat ever was in salt water) or perhaps shellfish?

No, I haven't.

I'm 3rd owner of this boat and as far as I can tell - it was never or rarely (doubtful) used in salt water. Boat sold new in KY, sold 2nd time to southern OH, and sold to me in KY.

It's basically a freshwater boat - and at 200 hrs, I'm hoping that this is not Bravo Fever.

I've got 3 things left - fuel cooler, block/heads, transom.

I don't think it's the block/heads as my pressure gauge is on port block lower. The restriction is prior to that point in the system (in theory).

Just 1 dip in saltwater, without proper corrosion mitigation could do damage. But it sounds as though that's probably not your issue. (BTW, the Pamlico at the old Fountain factory is salt/brackish.)

I've seen transom assembly corrosion/clog issues that mess up water flow, but same with coolers too.

And you are certain that your SWP/impellers are in perfect condition, right?