1994 Volvo 50 raw water pump failure

"Got a 1994 Four Winns 19ft wi

"Got a 1994 Four Winns 19ft with a 5.0 Volvo gas engine, serial # T01273537, Model # 502ACPMDA. The boat operates in fresh water and at the last outing it immediately heated up to over 240. The raw water impellor was slipping on the shaft, replaced it and the thermostat. I lubed the new impellor good with glycerin to aid in dry startup. With the boat sitting in the water, it immediately heated up to 240 again, and I couldn't detect water in the exhaust at the prop. (Probably melted the new impellor!)Where did I miss it? Is there a way to prime the pump before starting the engine? The inlet ports on the lower foot look perfectly clean, however this boat by necessity runs in some rather shallow water to get to the boat lift where it stays. How do I check water flow to the pump, and where can I down-load a diagram of the cooling system for this engine? Thanks in advance."

Was/Is the locking key in pla

Was/Is the locking key in place on the shaft???

"This pump will have the star

"This pump will have the star shaped drive shaft. Some of the original "Run-Dry" brand/style impellers were letting go of the hubs. Use the OEM or Sierra impellers.

This is a very long shot.... but if the shaft is slipping inside of the base, it will need to be replaced. Look for cracks in the base unit where the shaft is pressed in.

The pump should self prime with the boat in the water! Glycerin is OK.

Check the thrust surfaces in the pump body and on the cover. If either of these are worn, it may be causing what you describe.
Check all suction hoses and connections!

Do you have any issues with crustaceans in your water? These can get up inside and restrict flow.

Try this site and enter your engine/drive data.
http://www.marinepartseurope.com/en/volvo-penta-spare-parts.aspx"

i cooked my engine a couple of

i cooked my engine a couple of years ago AQ231A i have replaced the suction hose that went under the exhust manifold and altinator to the pump with a clear suction hose that i have run over the engine with a aqua flow alarm fitted in the in middle with this i can see the amount of water flow and the alarm sounds if i dont have enough flow has worked well now for 18 months this wont repair your pump but it gives me piece of mind as i am not going to cook another motor
cheers

"eastkimberley, As for the &#3

"eastkimberley, As for the "Peace of Mind"..... Your idea is OK..... but I'd caution you when replacing any suction hose with a product that may not be re-enforced to prevent collapse from negative pressure.
This hose must be correct for use on the suction side of your raw water pump system.
Just an FYI on that!"

I have a 5.0l that had a total

I have a 5.0l that had a totaled impeller when I purchased it.

Replaced impeller however it still periodically would get hot. Debris from previous impeller was in the system reducing flow.

What shape was your old impeller in?

"Brad, Yes....Good point, and

"Brad, Yes....Good point, and not talked about often enough. Whether Raw Water cooled, or a Closed Cooling system, you have to do some forensic work to see if you recovered all the pieces. More important on a raw water cooled engine given where these pieces can hide!
Closed system... they can only hide in one place!"

yes thanks Recardo
i have u

yes thanks Recardo
i have used true reinforced suction hose for that reason and its now been 18 months since the change and it is still working well
cheers