5.0L GL-B Cooling issues

tdamon30

Recruit
Joined
Aug 2, 2019
Messages
2
I'm having a problem with my boat not picking up raw water either in the water or on muffs. I did a complete raw water pump rebuild with a kit I ordered off amazon. The install went smooth but it overheated when I took it out the first time. I brought it home and started trouble shooting.

I put the muffs on and removed the inlet pump hose and had water to the pump. I removed the outlet and started the engine and no water. I know it must be something with the water pump, is it possible that I got a bad impeller? The few videos I've seen the impeller had to be soaked in soap water and even then it was a tight fit. Mine seemed to slide in without any effort. Wrong size impeller and not priming maybe?

I bought the boat used and have taken it out twice with no over heat problems. The original owner couldn't tell me when he replaced the impeller last so I figured I'd replace it for peace of mind. The impeller I pulled out was a VP stamped impeller, this one in the kit was not.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,306
Did you have the hoses reversed?

Did you back flush?
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
The impeller is a tight fit but soaking in soapy water shouldn't be needed.
The cheap aftermarket ones, the brass insert can break loose and the impeller not turn.
Take it apart and place the new on top of the old.
You should be able to tell if it's the same size??

Inspect the area around the insert for spinning insert.

Check the hose/ coupler on the drive.
 

tdamon30

Recruit
Joined
Aug 2, 2019
Messages
2
I removed the one I purchased and put the VP impeller back in. No more cooling issues. The impeller I ordered was the same diameter but the VP impeller was about an 1/8th of an inch thicker.

I ordered an OEM VP impeller. Lessons learned!
 
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