2 Questions

[dstaylor95]

1. Does the raw water sea cock need to be off to change the impeller on the raw water pump? I assume all i need to do is remove the impeller housing correct to change the impeller?

2. Best practices on "loosening" a plastic raw water seacock that is in the open position. It will close about 30 degrees. I dont want to force it.

Thanks in advance.

 

[Anonymous 121765]

DS,

By plastic, I assume you are meaning possibly PVC (white). This is not the valve you want to use in this application. I assume it's a ball valve (red handle). Get a Marlon ball valve to replace it before you do your impeller change out. You need to close-off valve before the impeller switch out.

If you’re experienced enough, you can change it out in the boat. The water pressure once the valve is removed will be about a foot high coming out the thru-hull fitting during change out but it does not have to be that bad if you are quick. If unsure, have a scuba clean guy cover the hole from underneath when changing valves.

Marlon valves are heavy duty and do not support marine growth. As for your impeller change out, sometimes they can be a bitch to free up off the shaft. Do not score the gasket flange area when doing this. If not sure, have an experienced friend or mechanic replace this. Use an anti-seize compound on the shaft to help with future change outs.

CR

 

[gpd955]

1. Does the raw water sea cock need to be off to change the impeller on the raw water pump? I assume all i need to do is remove the impeller housing correct to change the impeller?

2. Best practices on "loosening" a plastic raw water seacock that is in the open position. It will close about 30 degrees. I dont want to force it.

Thanks in advance.

You should have it closed. Anytime you open a the raw water system with the seacock open you run the risk of ingress.

You also should pull your boat ASAP if that seacock is not operational. All it takes is one bad hose and you won't be able to stop seawater from coming in. Especially I you are not aboard or you are asleep on board. I would definitely make sure that the bilge pump is working, too!

You can try to plug the thru-hull from the outside.

 

[Stu Jackson]

Plastic? CR makes note of plastic as white bod/red handle. If your seacock is BLACK, however, it could be Marelon, which is the appropriate material.

 

[Bob S]

You should read this post by Maine Sail on lubing and exercising your ball valves. Also search the archives, he wrote a great piece on changing out the impeller. It might be on his pb site. Good luck, it's not to difficult to do.

http://forums.catalina.sailboatowners.com/showthread.php?t=124971

 

[rbmcintire]

Thank you Bob S. I did not know about lubricating the ball valves. I'm still on the hard :cry:, so this is the perfect time to take care of that task. Seems simple enough. I have some engine, mast, electrical, plumbing, battery, cabinetry, hull painting, sails, rigging and bilge-related things yet to complete but splash down is getting nearer .

Rob

 

[dstaylor95]

Thanks everyone for the advice. I thought I would let everyone know how it went as this was my first experience doing routine maintenance outside of changing the oil on the engine (Universal M3-20B). Maybe incentive for others as well...

Changing the raw water impeller was easy. The hardest part was taking the hoses off. I did not close the sea cock as it stuck in the open position. I will get this changed out with a brass valve when I pull the boat out of the water for bottom paint. I pulled the hoses off and kept them above the water line with no issues. Some water came out but nothing substantial. Taking the pump housing off was easy, unbolted the bolts and it almost fell off. Pulling the impeller off was no issue as I used some needle nose pliers. I took a picture of it prior to pulling it off to match the rotation of the old impeller. That said I really dont think that the rotation is that much of a issue when you put it back on. Checked the integrity of the pump housing and placed the new impeller in. I forgot to lube up the pump housing for the initial start since there was not going to be water in the pump when starting the motor. Used water based marine grease to keep the o-ring in the pump groove and this also helped keep the gasket in place when putting it back on the pump. I recommend lining up the key prior to putting the o-ring and gasket on. Tightened the bolts and started the motor, it took about 5 secs for water to start shooting out the back. Very simple. I kept the old impeller for a spare, it appeared in good shape.

I then changed the fuel filter and the filter on the fuel pump. I dont think that I have a fuel shutoff valve and I removed the fuel filter anyway. Make sure that you have something below it to catch the fuel that spills out. I then pulled off the filter and poured the fuel that was in the old filter into a clear receptacle and then poured that fuel into the new fuel filter prior to screwing it on. I then changed the fuel pump filter which was even easier.

The last item of business was replacing the air filter which was straight forward as well. I ran the motor for 20min to check for any leaks and everything checked out fine.

All in all, it took about two hours and was alot easier than I thought it would be. I found it very beneficial as this maintenance let to a better understanding of the engine and would recommend this to all novice/beginner sailors.