help with cooling system

[almost perfect 2]

I have a westerbeke 10-2, diesel inboard. It is cooled with both fresh water and sea water.
the intake for sea water (thru hull) has a sea cock that can be shut off and another valve above it in the boat with a hose attached that should suck water . when I ran motor with the hose in bucket it did was not pumping water out of the exhaust. Last year while in the water it worked fine with the thru hull suction?
I closed the thru hull valve and opened the one with the hose attached.
did not want to run it for long with no water running out of the back.
can anyone offer any suggestions or help?
Thanks

 

[Don S/V ILLusion]

I can't understand your description. Perhaps that is why others may not have responded.

Specifically, "another valve above it in the boat with a hose attached that should suck water."

If I understand you, the problem may be a lack of water in the filter.

 

[Hydro Therapy]

The hose for flushing may have a spring loaded valve that keeps the water from the bucket from being sucked in. You may need to run the hose water from a faucet so it is under pressure. Look into the flush water attachment. If you see a ball then the supply needs to be pressurized or the ball needs to be pushed in to allow the water to be sucked from the bucket.

I'm not familiar with your motor. My last boat (Motorboat) was a straight inboard and had the flush system I mentioned.

 

[almost perfect 2]

Let me try and explain it better....
The thru hull raw water intake for cooling has a shut off valve with the hose that leads to the
motor for cooling. coming off of that hose is a second shut off valve with a hose attached which looks like it is for emergengy de watering, or to run the motor with the end of the hose in a bucket while the boat is on dry dock. By shutting off the thru hull valve and opening up the other valve it should suck the water out of the bucket, cool the motor and exit out of the stern exhaust pipe.
it does not seem to be sucking the water out of the bucket. Not sure if it is self priming, or if I did not run the motor long enough?
It worked fine all last season while the boat was in the water as far as far as cooling by sucking in sea water and exiting out the stern. This is the first time I have tried the hose attached to the second valve.
Was trying to warm up the motor and change the oil prior to going in the warer.

 

[Nom De Guerre]

Where is the raw water strainer in the system? Assuming there is one - is it closed and not allowing air to be suctioned in?