Removal of Raw Water Pump and Intake Hose on DD 8v71

[Hoghead65]

1st questions? Removed old impeller, it was thrashed, tines missing. Pulled pipes to heat exchanger off, removed core and took to get cleaned at a radiator shop that does marine. Now we need to take large intake hose off, the one that runs from the sea cock to the salt water pump. It won’t come off, it’s old...should we cut it off and install a new hose????? 2nd question? Are the times in the inter cooler? How do we find them? We looked in all the pipes to the HE nothing. 3 rd question? What antifreeze do you use for theses motors? We researched and found a Detroit powercool 50/50, can we use that? Reason I asked is a person who deals in parts said “don’t mix antifreeze like red with green it will gel up” scary. We think it had pencool 3000, but we don’t know it was just what was in the boat, the liquid that came out was rusty and brownish?Any help would be appreciated. #newdieselowners#tearupitscheaper#SouthernCalifornia#

 

[Hoghead65]

Salt water pump not a raw water pump.

 

[Avenger]

If a salt water pump isn't a raw water pump, what is?

If you don't know the history, replace the hose. If you have to cut it be careful not to damage the fittings. Cut marks on the barbs can become leak paths. Or invest in a hose pick. You work that in between the hose and the fitting to break the bond. Much easier than cutting, and safer too.

Pencool 3000 is an SCA - supplemental coolant additive that is designed to refresh the additives and extend the life of glycol antifreeze. You probably had standard green and if it's gooey and rusty etc it's time to drain and flush the system and replace with new. Powercool 50/50 is standard antifreeze - basically the green stuff. Use that, get the test strip kit so you can tell when the additives are getting tired, use the SCA and change the antifreeze as recommend by the manufacturer.

The impeller blades are probably stuck in the first heat exchanger in the system. You didn't say what 8V-71 you have, so you'll just have to follow the hose to find where that is. If that's the intercooler, that's where I'd look.

 

[racclarkson@gmail.com]

Powercool is purple.

 

[Hoghead65]

What type of 8v71???? All I know is that it is a 8v71 ti...in a 1980 Hatteras 46’ convertible sport fisher. Is there more info needed?

 

[Nonchalant1]

Impeller blades likely stuck in the intercooler. The standard ones are very hard to see or feel inside. You can remove the whole intercooler by taking off the 2 hoses and mounting screws. Then attach a garden hose or similar to the outlet side and backflush it while bumping it carefully and moving it as the water exits downwards. I got a number of impeller blades out of mine like this. Of course, if one engine is like this, the other will likely be also.

 

[Captain Ralph]

What type of 8v71???? All I know is that it is a 8v71 ti...in a 1980 Hatteras 46’ convertible sport fisher. Is there more info needed?

8V71TIs come if different configurations.
ITs on top of the blowers, or for low profile engines, ITs on the back of the engine.
I have witnessed other configs also.
Some pics could help here also.

I was working on low profile 6V92TIAs last week. What a plumbers nightmare.

 

[Captain Ralph]

Power Cool from DDC is probably the best purchase you can make.
Power cool will work fine in your gen-sets fine also.

Avenger has a good point about using the test strips to test the coolant every year.
Shelf life on the strips are questionable so order fresh strips in before use.

 

[Hoghead65]

he removed the salt water pump and a gear fell out. This gear has numbers and an arrow stamped in it the numbers r 0179. The arrow...he is thinking is used to line it up when putting back in are the numbers a date? How do u put the gear back in, can’t see if there is an arrow to match up where it goes, gonna clean up inside it’s a bit oily.Anyway you can send pictures on this forum? #portengine#willbeeasy#knowingurengines#important#

 

[Captain Ralph]

The inter coolers usually get the raw water before the big heat exchanger. The end of the IT towards the raw water pump is ware I would look first.

Oil coolers & fuel coolers get first or second hand supply of this same cool water.
Depending on the design of these devices (if used), this may be ware some impeller bits have flowed and are trapped at also.

 

[Captain Ralph]

he removed the salt water pump and a gear fell out. This gear has numbers and an arrow stamped in it the numbers r 0179. The arrow...he is thinking is used to line it up when putting back in are the numbers a date? How do u put the gear back in, can’t see if there is an arrow to match up where it goes, gonna clean up inside it’s a bit oily.Anyway you can send pictures on this forum? #portengine#willbeeasy#knowingurengines#important#

Ah, The gear adapter. Detroits joke on the unknowing.
You can hand fit it to the pump and hand fit it to the cam end in any orientation.
Give it a try to prove it to your self.
Putting it all together at the same time will drive you crazy.
Remember this the next time you reach to pull any direct drive option off of any engine.

First, leave the impeller out and cover off during this assembly. This way you can rotate the shaft by hand helping the gears mesh.

Leave the hose adapters off of the pump (if you can) until the pump is bolted back on.

Glue the gasket to the pump (in perfect position) with a very thin coat of RTV 30 minutes before trying to re-install the pump. If using a O ring, glue that in also.
You are going to get frustrated enough, a falling gasket or O ring will just tic you off faster.

A fresh drop of RTV on the bolt threads and snug all up in a busted pattern.

Remember Tef-Gel on all the machine screws into the bronze pump housing.

 

[Boatsb]

he removed the salt water pump and a gear fell out. This gear has numbers and an arrow stamped in it the numbers r 0179. The arrow...he is thinking is used to line it up when putting back in are the numbers a date? How do u put the gear back in, can’t see if there is an arrow to match up where it goes, gonna clean up inside it’s a bit oily.Anyway you can send pictures on this forum? #portengine#willbeeasy#knowingurengines#important#

The arrow points up. It's easier to align that way.

Go ahead and prove me wrong.


Now reality aside.

Send the pump out to be fully evaluated and properly rebuilt. If you don't have a history on it get it back to like new with bearings and seals.

I've had many DIY pump renewals prove bad. I pulled 2 off 8v92 ti engine with new impellers all torn up. The cam and other parts were badly worn and shafts pitted.

 

[Hoghead65]

Pictures attached

 

[Hoghead65]

Thank you it’s exactly what u said driving him crazy and frustrating.. pump is being rebuilt tomorrow, will get core back tomorrow took to a shop to clean and pressure test. Gonna go get RTV AND TEF- Gel also. He’s gonna get into the intercooler today to try to find pieces. He will have more questions as we move forward... Thank you all so much this forum is awesome. Can’t get anyone here to talk to us like this they just want us to pay them a fortune to do it for us.#wecandothis#willbegoodexperience#keepuposted#

 

[Hoghead65]

Another question.. the pipes that go to the heat exchanger and the others go to the raw water ( what is the right term...raw water or salt?). Anyway there where small cracks towards end where hose clamps go, cleaned and soldered inside and out. Is that okay or do we need to replace pipes?

 

[Hoghead65]

Looked in intercooler where water goes in with a flexible cam didn’t see any impeller tine pieces. Could they have possibly disintegrated or been backflushed out? is there another place to look.

 

[SKYCHENEY]

Look through the whole raw water circuit. Pieces could be in the fuel cooler, heat exchanger, or even the shower head where the water enters the exhaust.

 

[Captain Ralph]

Looked in intercooler where water goes in with a flexible cam didn’t see any impeller tine pieces. Could they have possibly disintegrated or been backflushed out? is there another place to look.

At the IT raw water inlet, look to the bottom where stuff would fall.
What ever you do, do not start sending anything stiffer than jello into the IT tubes.
Also, do not unbolt the end covers.
Use a high volume shop vac to draw anything back to the raw pump end of the IT.
If you must, flush with a water hose or 25psi air backward, from the HE to the raw pump.

Pending the amount and type of impeller damage, You may not find all of the bits.
How old was that pump impeller?
Were the Raw water pump shaft seals leaking? or pump damaged?

 

[Captain Ralph]

Look through the whole raw water circuit. Pieces could be in the fuel cooler, heat exchanger, or even the shower head where the water enters the exhaust.

If the bits of impeller were small enough to pass thru the main HE, I do not see any need to check out the shower heads (dump cans, exhaust mixers).

 

[SKYCHENEY]

If the bits of impeller were small enough to pass thru the main HE, I do not see any need to check out the shower heads (dump cans, exhaust mixers).

I always thought that too. Then I found a bunch of pieces in the showerhead. I have no idea how some of them could have made it there, but they did.