Cooling System 1997 Mer 5.7LX

Hello, first time user. I must start off by saying I have learned many new techniques and I have become more knowledgeable due to this site. Keep up the good work! Well I have a 1997 MerCruiser 5.7 LX OKO26695 Bravo 3 (in a 1997 Doral 230CC). Last weekend I was planning on winterizing for the year. (It?s been about 2 week since last time out, ran great no problems) I started the engine preparing to change the oil, however my serpentine belt stayed stationary along with all components; O'ya sounded like a cat was in there too. I removed the serpentine belt and tried to turn ever pulley by hand. My raw water sea pump was ceased. I replaced today, along with checking intake for any blockage ETC. Started engine up, all looked good, until I saw no water coming from my thru- hulls. I double-checked both hoses to sea pump, I have water there, and I bleed the lines just in case?same results. Must be somrthing else! Next weekend I plan on tracing the cooling system, looking at the circulating pump, and replace t-stat. My questions are. Am I on the right track? Dose anyone have time saving tips, can you point me in the right/ different direction, have any other ideas or suggestions? Thank You in advance.

Re: Cooling System 1997 Mer 5.7LX

Started engine up, all looked good, until I saw no water coming from my thru- hulls.

Click to expand...

The most obvious and easiest mistake to make (I have made it a few times) is to get the inlet and outlet hoses on the pump wrong.
It's SOOOOOO easy to do backwards while standing on your head.
If your not sure, head for the Adults only sticky at the top of this forum and download the OEM service manual. It shows where the hoses go.

Re: Cooling System 1997 Mer 5.7LX

Don S. you?re the best! When I installed the hoses I made sure I put the ears on the out drive to make sure I installed the intake hose to the "in" on the pump. Iam 100 % sure that its right. Left H. ROT out ...outlet line must be on top.

Re: Cooling System 1997 Mer 5.7LX

The "in" depends on the rotation.very easy to get backwards. Remove the hose that goes to the therm housing, install muffs, do a quick start and stop.
No water out the hose means the inlet and outlet from the pump body are reversed.

Re: Cooling System 1997 Mer 5.7LX

This is my lesson learned while installing a brand new raw water sea pump and bracket too engine. I removed old original pump and bracket, due to it being FUBR.

When the pump arrived I examined/compared then installed, remember this the pump was already attached to the bracket when it was delivered. I installed bracket to engine, then installed hoses, then removed thermostat hose looking for water(one man Band). Started engine no water...WTF...

OK you heard all of these stories before. Iam going to keep it short. The main point, make sure that when you receive a new part with an already attached bracket, that the bracket is attached to the part the same way as the old one. Same Same. My fix, I need to remove the 3 bolts from the pump/bracket then rotate the bracket a few holes to the left for the pump to work.

(standing at stern out let is closer to the engine...out let is about 11 oclock and inlet at about 5 oclock.
The mistake was outlet about 2 oclock and inlet 8 oclock.) This wont happen to me again ...the mistake that is

Re: Cooling System 1997 Mer 5.7LX

Very good point. As easy as it is to mix those hoses up, having someone move the pump in the bracket would make it 10x easier.