Sea Water Pump Rebuild Question

[2ifbyc]

I am doing the standard seawater pump rebuild kit on a 1990 Mercruiser 454 Bravo 3. There are 2 hoses that go into the back of the housing. 1 hose goes to the drive and the other to the engine. The housing is marked LH on one port and RH on the other. Which hose goes to which port? It sounds to me that they should have marked it in and out and not lh and rh. Im sure its obvious to you experts out there. Thanks in advance Mike

 

[Anchor Management 1]

Re: Sea Water Pump Rebuild Question

Well mostlikley you have a left hand rotation engine.If you crank the engine over,looking from the back of the engine what way does the flywheel turn?

 

[2ifbyc]

Re: Sea Water Pump Rebuild Question

Looking from the back its CCW. Looking from inside the boat at the front of the engine (looking at the belts and pulleys) its CW.

 

[Anchor Management 1]

Re: Sea Water Pump Rebuild Question

Ok it is a left hand rotation engine,On the pump you said it has LH and RH by the LH there is an arrow follow the flow.

 

[2ifbyc]

Re: Sea Water Pump Rebuild Question

After putting it back together today it made a belt squeaking noise and then started smoking and smelt like burnt rubber. I am assuming that the hoses were reversed and I possibly burned up the new impeller. I didnt want to just switch the hoses around in case they are in the right way now. HELPPPPPP!!!!!!

 

[Anchor Management 1]

Re: Sea Water Pump Rebuild Question

If I remember right the top hose goes to the engine. You should not have burned it up becouse water is luberacating the impeller.

 

[2ifbyc]

Re: Sea Water Pump Rebuild Question

Well after I put it back together it smoked and squeaked and the temperature gauge went from 100 to 200 in like 10 seconds. What do you think the issue might be? The whole reason I even did the rebuild was because the engine had been running hot when I go fast and fine when I idle. Now it seems Ive created more problems with the rebuild kit.

 

[picklenjim]

Re: Sea Water Pump Rebuild Question

One way you can determine if you have the hoses on right is to disconnect the hose from back at the drive. Hold it up and fill it with water. Then have someone hit the key for a couple of seconds and if it's right it will suck the water down real quick. If it don't then swap the hoses and try again. Sorry to say but you probably ruined your new impeller. When you install the impeller you should lubricate it with vaseline or liquid dish soap.

FYI all Mercruiser Stern Drives use LH rotation engines. I believe LH and RH on the pump relates to if you have old style belts or a serpentine belt which turns the pump the opposite direction.

 

[jerryb1]

Re: Sea Water Pump Rebuild Question

Are you sure the pump bearings aren't bad? Does it turn with the belt off? Are you adjusting the belt too tight? just some thoughts.

 

[2ifbyc]

Re: Sea Water Pump Rebuild Question

How would I check if they pump bearings are bad? The pulley will spin by hand when its off the engine but not freely and easily. Its tough to spin and makes a noise.

 

[picklenjim]

Re: Sea Water Pump Rebuild Question

How would I check if they pump bearings are bad? The pulley will spin by hand when its off the engine but not freely and easily. Its tough to spin and makes a noise.

They WON'T spin easily. The rubber impeller is tight in there and will squeek and be hard to turn. That's normal. Squirt some oil in there. It will help save the impeller during intial start up.

 

[jerryb1]

Re: Sea Water Pump Rebuild Question

That's correct it will not spin easily, but if your belt is burning up when you start it, something is binding. It's a good chance the bearings are bad or flow is blocked. Did you have some play in the belt when you adjusted it? If you used a bar or something and really tightened the belt too tight, it will cause problems.
I would take the hose off the outlet side where it connects to the engine and see if the pump works. Maybe you have a clog on the output side.

 

[picklenjim]

Re: Sea Water Pump Rebuild Question

At this point I would take it all back apart and check the impeller. If it was smoking as you said earlier then it's probably ruined. With the impeller out you can spin the pump by hand to check the bearings. Be sure to lubricate the rubber impeller when assembling.

 

[2ifbyc]

Re: Sea Water Pump Rebuild Question

OK so today I took the pump apart and rebuilt it. It turns out I had the hoses reversed and had the impeller spun in the housing the wrong way. The new housing actually cracked. I bought a new one and put it in the right way. Works great now. While I was working on the engine I noticed the circulator pump was very rusty. I decided to replace that as well. Not a bad job at all. Everything is back together and running smoothly. Oh by the way... There was no thermostat in the boat either. Cleaned up the housing, installed a new stat, flushed all the hoses and all systems are a go! Thanks for all the great advice guys! Much appreciated! The only problem I have now is the temp gauge was reading dead low at 100 degrees. I think I may have a bad sender on the thermostat housing. It has 2 wires running to it. 1 on each side of the housing. Maybe Ill replace the sender tomorrow.. Thanks again Guys! Mike