Marine Seawater Pump Maintenance

Pumping salt water these pumps require regular maintenance. The most common problem is a worn or broken impeller. Followed by a bad seal…the problem with a bad seal is it leaks salt water that gets sprayed all over the engine and creates corrosion. Marine Hose Clamp Upgrade. Santa Barbara Marine Diesel Mechanic can rebuild/replace your faulty pump on 95% of all makes and model Marine Diesel engine. Even with regular servicing, a marine seawater pump can fail, which is why it’s highly recommended that you keep an extra flexible impeller onboard your boat to swap in should your seawater pump fail at an inopportune time. If you need any parts for your marine water pump or any marine diesel engine component, Marine Seawater Pump Maintenance.

The seawater pump moves water from the intake strainer into the engine’s heat exchanger. The engine spins this pump by means of a belt or gear. Knowing which type of pump you have is critical. If it is belt driven, it likely shares this belt with the alternator. If the alternator seizes and you cut the belt, then you lose the seawater pump and therefore the engine. If it is gear driven, however, it might be possible to cut the alternator belt and keep cruising.   Fisheries Supply

Marine Seawater Pump Maintenance Steps

You should make a habit of checking the impeller on a regular basis. To do so, follow these steps:

1. With the thru-hull closed, unscrew the end cover screws and remove the cover and gasket. You can use a pair of needle-nose pliers to grab the hub of the impeller and pull it out.

2. If you’re struggling to free the impeller, remember that there’s also an impeller puller tool you can order for this purpose. Do not, under any circumstances, try to pry the impeller out with a screwdriver, as doing so will almost certainly damage the housing.

3. Carefully inspect the impeller. Look for any cracked vanes or vanes that are bent out of shape. They should be round. If any of the vanes are damaged, replace the impeller.

4. Assuming the impeller looks in good shape, return it to the housing. First, lubricate the inside of the housing with a light layer of petroleum jelly or some other lubricating grease. Then, lubricate the impeller with diluted dishwashing liquid before reinserting.

5. You may need to use a fresh gasket and/or cover when you’re reassembling.

6. If you’re replacing your impeller with a new one, be aware that different materials are used to make impellers. They can be made of neoprene, nitrile or polyurethane. For your purposes — a marine sea water engine cooling pump — you’ll want a neoprene impeller.