Full or half fresh water cooling system??? - Maxum Boat Owners Club

rgreenwell8962 · 03-02-2009, 08:57 PM

I am having trouble determining whether the freshwater cooling system on my 5.7 Mercruiser Bravo 3, in my 2001 2500 SCR is a full or half system. Question #2: if in fact it IS a FULL system, does this mean that I do not need to flush the system following use in saltwater?

seapuppy · 03-02-2009, 10:39 PM

what determines whether you have a full or half is that the risers are also filled with coolant...if it's just the engine and heat exchanger....then it's a half system.....

if your in salt water...and stay you pull the boat out...then yes...always flush the system.......if your say in salt water and drive into a lake or river..that is fresh water..your done....but like my situation...I run in salt water...come up a brackish river...and sit on blocks...thus..I flush....it's run for about 15 min....and I'm done...saves alot of wear and tear on the risers and exhausts....

Sp

Stressleave · 03-02-2009, 10:55 PM

SP
So you are saying that if you do have a full closed cooling system that you do need to flush after you come out of the salt water? :?

I thought I was done with that now that I have a full cc system.

Paul

seapuppy · 03-02-2009, 11:56 PM

always..if your in salt water...it's best to flush...I have a full up system..but was told by the mech. to flush at least 15min after use....I come up a brackish river and still need to flush....

Sp

rgreenwell8962 · 03-03-2009, 02:52 AM

How can I tell if my system is full or half????? That is what I cant figure out.
Thanks

seapuppy · 03-03-2009, 03:23 AM

full systems have hoses going to the riser from the water pump usually...

SP

rgreenwell8962 · 03-03-2009, 04:52 AM

Thanks SP. I'll have to look. May send you a picture as well....

Brit Rider · 03-04-2009, 01:42 AM

I'm more familiar with inboard ski boat style applications but don't most full systems still have a wet exhaust that is cooled via salt? The intake via the leg is still sucking salty water regardless isn't it?

seapuppy · 03-04-2009, 02:47 AM

yes..but the jacket around the exhaust manifold and risers has coolant around it.....

SP

hawkip · 03-04-2009, 02:56 PM

Good question. I came across this while researching a FWC setup for my rig. I have the same engine, and want to install a half system later this Spring. Thought it was a decent explanation.

seapuppy · 03-04-2009, 04:09 PM

excellent hawk....thanks......

Sp

Brit Rider · 03-04-2009, 10:51 PM

I used to have a full closed cooling kit on a Ski boat a few years ago... when looking into whether to pay for the option or not I remember being told that adding a fresh water kit to a boat that had been exposed to salt for any amount of time was a false economy and not worth doing.

The gist was... do it to begin with or don't bother.