Water pump challenge

Hi Crew- We took boat out of water onto trailer. Jacked the front end up to shed winter rains and run-off.
We then attempted to pump antifreeze into raw water intake. Wouldn't pump. Dropped boat down to level- still no pump.
Impeller with about six hours on it was replaced with new impeller, 0-ring, and gasket. Still won't pump.
I'm wondering if maybe I got an air-lock when we lifted the nose?
We bypassed valves and filters with a straight run to input side. We even disconnected the output side from the pump. Still nothing.
We examined the connections ans water pump housing for leaks, cracks, chips, etc.

The pump seems fine and worked up until we lifted the nose. Never had anything close to a problem with pump and pumping.

What's up with this.
Thanks-
Eeber

What engine? When was it run last in the water? No cooling problems then? How are you providing the antifreeze to the intake side of the raw water pump?

I use a Sea Flush adapter that replaces the top of my strainer and sucks the antifreeze into the engine from a 5 gallon bucket. Works well and I have never had an airlock problem. No affiliation just a satisfied customer.

It's a 4 cylinder Isuzu Pisces diesel.
Last time it ran in the water was when we were taking it out (3 days ago).
It had 6 hours on new impeller. It was working fine.
There is a "T" in the raw water intake with a valve to turn it from lake water to a hose that lays in the bilge and acts like an emergency bilge pump. I've used this for several years to add antifreeze.

I had the screw that holds the cam in place inside the pump break on my center console this summer. The cam spun inside the pump and blocked the ports.

Also I always have difficulty getting my Air conditioning pump to prime in the spring. I think the antifreeze foams a little and won’t pump. Works fine the whole season after the antifreeze is out.

Another thought- while pump was off, we played with it at a water faucet.
Pouring water into the inlet and water came out the outlet. I don't believe it should?
Also, the pump is 38 years old. Is the liner in the pump maybe worn out?
Thanks for all the input.

Your pump may well be worn, given its age, and ready for replacement. But it is hard to see how it would have behaved well enough during normal use, yet have difficulty priming. As a quick fix for winterizing, perhaps you can disconnect the hose from the inlet strainer to the engine and add a temporary extension. If you can extend the hose and raise high enough to gain a reasonable head height above your water pump, you should be able to prime the pump. With 2 persons should be possible to pour antifreeze into the hose extension with a funnel while operating engine to pump antifreeze through the system.

The hose that we normally draw our antifreeze from was held in the air and filled. When the engine was turned over, well, it didn't flow.
Something so simple but I'm stumped.

Is the valve in the T opening? I’ve seen valve stems break. The valve looks open but it’s not. When you opened the T valve did you close the seacock? Did the seacock actually close?

Concerning your water faucet test, very little water should get through. Better open the pump and take a look inside. At that age it is probably worn. Most wear occurs on the inside of the face plate and the wear plate at the rear of the pump where the sides of the impeller ride.

Anything that could restrict flow? Clogged cooler? Clogged heat exchanger?
Even iff you changed it 6h before, did you check the impeller, it may have fail for any reason...

L

I just went and pulled the pump again. This time I was alone, if you know what I mean. The first thing I noticed was the face plate was not sealed tight to the housing.
I could actually see light through the side of it. It appears the plate was sitting on the 0-ring.
The next thing I noticed was that the gasket was all wet.

I examined the inside of the plate and wasn't sure which grooves should be there and which should not. There was also a thin line of new scratches on the plate roughly where the fingers met the hub. They extended down to the top of the cam at the cam only.
At this point, I will be ordering a new pump with confidence that was the problem.


I sincerely thank everyone for their input. It helps the mind focus.


Yours-
Eeber

I didn't find a pump without a base so I'd have to cut off the base before even using it. While looking, I found a face plate and ordered it.
The new face plate didn't make a difference so I'm back where I started.

For anyone interested it's a Jabsco 1673-1001.