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Dottiesboat
04-13-2005, 11:24 PM
I need an engine circulation pump for a '99 LTR (Chev 350). The engine uses raw water cooling.
Why can't I use an automotive waterpump with a lifetime warrantee since they seem to only last about two years.

Does rotation direction of the pump matter?

Why do the seals fail at about two years.

Is there an update on the seals?

NatesGr8
04-19-2005, 08:44 PM
I believe automotive water pumps are different than boat raw water pumps because they do not self prime and therefore you will not be able to pull any water unless you put your raw water pump below water level. I would suggest sticking with the marine raw water pump. If anyone else knows any different please post it here.

wesgardner
04-20-2005, 08:17 AM
Just to clarify things...

There are two pumps - raw water pump (only boats have these)

engine circulation pump - I believe these are a component of the engine and therefore are NOT part of the marinization process (i.e. - you can buy one at an auto parts store)

Dottiesboat - I assume you're talking about the engine circulation pump? as you've stated

Wes

Engine Nut
04-20-2005, 12:14 PM
I need an engine circulation pump for a '99 LTR (Chev 350). The engine uses raw water cooling.
Why can't I use an automotive waterpump with a lifetime warrantee since they seem to only last about two years.

Does rotation direction of the pump matter?

Why do the seals fail at about two years.

Is there an update on the seals?

The circulating pump on your engine, belt driven near the top of the engine, is a pump that is unique to the marine industry. It is unique in several respects. The impeller in the pump is generally bronze or some other non-corroding material and is bi-directional, the back-plate is stainless steel - non corroding and the seals are designed to run in raw water not in anti-freeze. A change in the seals on the GM supplied pumps happened two or three years ago and the longevity has improved significantly. It is hard to keep seals in those pumps because raw water does not lubricate as well as anti-freeze. There is typically debris (sand etc.) that goes into the engine with the raw water that is particularly hard on seals as well. If your dealer buys pumps from MasterCraft or Indmar, they should have the improved seals.I can't speak for other circ pump sources.

André
04-20-2005, 12:22 PM
Engine nut
Where have you been hiding all those years ???
Man,it's fun to read good ,clean ,understandable answers...
We should start a new thread: "Ask Engine nut ".

AirJunky
04-20-2005, 12:28 PM
Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine.... it sucks water from the intake grate under the boat. The engine also has a circulation pump which in turn has a separate device on the front of it that houses the impeller. I have not heard there is anything different about the automotive & marine circulation pumps, but it's possible the seals could be different as Engine Nut said. But the circulation pump CAN be replaced without effecting the impeller housing.
You might check with http://www.skidim.com on this. They really know their inboards & are great at stuff like this.

André
04-20-2005, 12:35 PM
Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine....
Electrical pump ???

Engine Nut
04-20-2005, 12:45 PM
Ditto what Wesgardner said...... the raw water pump is an electrical pump (on my '94 205) on the port side down by the stringer under the engine.... it sucks water from the intake grate under the boat. The engine also has a circulation pump which in turn has a separate device on the front of it that houses the impeller. I have not heard there is anything different about the automotive & marine circulation pumps, but it's possible the seals could be different as Engine Nut said. But the circulation pump CAN be replaced without effecting the impeller housing.
You might check with http://www.skidim.com on this. They really know their inboards & are great at stuff like this.

The raw water pump is direct driven off the crankshaft on an Indmar engine. It has a rubber impeller and supplies raw water to the engine. This pump is connected directly via a 1 1/4" ID hose to the through hull pick-up on the bottom of the boat. On some applications, there is a transmission cooler between the water pick-up and the pump and on others the trans cooler is between the pump and thermostat housing. There are no electrical water pumps supplying water to the engine, unless somone has added one for some reason.

wesgardner
04-20-2005, 12:51 PM
Hey Engine Nut

Didn't know the circ, pump was different for marine engines....mine's been fine for 15 years....I have replaced my raw water pump, however....

Airjunky, what pump is electrical? Mine are either belt drive (circ.) or crank drive (raw)


Wes

Footin
04-20-2005, 01:24 PM
My raw water pump is leaking out the back, is it easier to buy a new pump or take it off and have a new seal pressed in?

Granite_33
04-20-2005, 01:27 PM
My raw water pump is leaking out the back, is it easier to buy a new pump or take it off and have a new seal pressed in?
What type of pump? Johnson?

Footin
04-20-2005, 01:32 PM
Yes Johnson, It is on a 1994 PS 205 with a 350 TBI.

I should have said that befroe.

Granite_33
04-20-2005, 02:28 PM
Yes Johnson, It is on a 1994 PS 205 with a 350 TBI.

I should have said that befroe.
Don't buy a new pump. The seal is a definite fix.

When I replaced my seal, I called around and got some differing opinions.
#1 remove pump, press out the shaft, #2 Pull the seal out the front.

The local dealer I talked to was about 50/50 on both.........
If they had it in their shop, they would have pressed the shaft out and replaced the seal that way. (I never asked for a price to do it)
However, the service tech said that #2 was "most likely" OK too.
The reason I did it #2 style was that damaging the old seal in removing it was harmless since it was useless anyway.

Replacing with a new seal was a matter of assuring the shaft had no burrs on it that could damage the new seal, then pushing it back into its seat using a deep well socket as a "pusher" assuring equal pressure on all sides.

It definitely worked, as I replaced it in May 04 and went the entire summer and fall with no issues, leaks, drips, etc.

$20 fix for doing it myself, and I'm not sure what the dealer would have wanted, since I decided early on to do it myself anyway.

All that said....you can have the dealer do it, for a fee.....or you can do it yourself the way the dealer did it if you have the appropriate presses, etc......or you can do it the way I did it.

Either way, there is no need for an entirely new pump. The seal is about $20 at DIM, new pumps are about $150 or so... :twocents:

tpttool
04-20-2005, 02:47 PM
i always get my parts from dooker. i can give you good deals. yeah he works down at the pick and pull. just on the other side of my house.

Footin
04-20-2005, 03:24 PM
Tool,

Can Dooker get me a good deal on a new tube?

Granite_33
04-20-2005, 03:42 PM
i always get my parts from dooker. i can give you good deals. yeah he works down at the pick and pull. just on the other side of my house.
Pick and Pull.......does this have to do with nose care?

AirJunky
04-20-2005, 05:31 PM
Hmmmm, too damn many pumps. So when I worked with Heatercraft on my heater install, the R&D guys referred to a "raw water pump" which is located on the port side stringer, under the engine & had 2 wires to it & a large hose to & from it. This pump sucks water from the intake grate when the boat is under power, then sends it to the other pump on the front of the engine. The first pump is also much higher volume as it's providing water to the 2nd pump, plus the exhaust manifolds, and now the heater. Because of where it's located, there is no way a belt or crank drive connection would be possible.
Hope that muddied the waters a bit more.

jimmer2880
04-20-2005, 07:02 PM
Hmmmm, too damn many pumps. So when I worked with Heatercraft on my heater install, the R&D guys referred to a "raw water pump" which is located on the port side stringer, under the engine & had 2 wires to it & a large hose to & from it. This pump sucks water from the intake grate when the boat is under power, then sends it to the other pump on the front of the engine. The first pump is also much higher volume as it's providing water to the 2nd pump, plus the exhaust manifolds, and now the heater. Because of where it's located, there is no way a belt or crank drive connection would be possible.
Hope that muddied the waters a bit more.

That still doesn't sound right. The pump you're describing sounds like my bilge pump, except for the grate thing.

On every inboard I've ever seen - the grate connects to the trans cooler, then to the crank/or belt driven raw water pump, then to the typical auto-style water pump.

I wonder if someone did some mod's to your boat before you bought it?

Can you post a pic?