65mustang 302 water pump issues

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Offline Phillip28

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65mustang 302 water pump issues
« on: March 10, 2023, 09:26:27 am »
Hi all so I got the firing order sorted and started my engine up for the first time.sounds sweet. Big problem is bottom hose stays cold is this a thermostat issue or do my water pump as I changed it to put the pipe outlet back on passenger side to line up with mustang radiator? Has anyone done this conversion on here before later model windsor 302 that can advise me please or do I have to use the water pump with outlet on driver side and make connector pipe to other side ? Thanks Phil

Offline Clubman7

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Re: 65mustang 302 water pump issues
« Reply #1 on: March 10, 2023, 09:35:55 am »
When I first started mine in it had a big airlock in the engine.
Couldn’t get it out.
Googled it and the recommendation is to drill a 3mm hole in the thermostat to help bleed the air.
Fixed the issue.

Offline Phillip28

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Re: 65mustang 302 water pump issues
« Reply #2 on: March 10, 2023, 09:47:18 am »
Oh I did see that somewhere so does that mean there is no direction change in water pumps with out let pipe difference

Offline GEOFF289

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Re: 65mustang 302 water pump issues
« Reply #3 on: March 10, 2023, 02:25:02 pm »
Mine has a 5.0 roller engine with a water pump to suit the original Mustang plumbing with both in and out on the passenger right. I don't have cooling problems so I don't think its this configuration causing your problem.

You can crack the temp gauge sender on the manifold, i.e. at the top of the cooling system, just slightly to let any air out. If coolant starts leaking as soon as you crack it open an air pocket isn't your problem.

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Re: 65mustang 302 water pump issues
« Reply #4 on: March 10, 2023, 07:49:43 pm »
Hi Phillip,
302 roller motors have a water pump that spins in the opposite direction as the early 289/302 water pumps, so if you have swapped to an early style water pump, make sure you have changed the pulley system so that its rotating as per an early motor. Otherwise your pump is trying to push the water in the wrong direction .

Regards

Offline GEOFF289

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Re: 65mustang 302 water pump issues
« Reply #5 on: March 11, 2023, 07:46:33 am »
He says he changed the pump to put the inlet and outlet on the same side. He couldn't be running the serpentine belt set up with that pump.

Offline Phillip28

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Re: 65mustang 302 water pump issues
« Reply #6 on: March 11, 2023, 08:12:02 am »
Hi no it runs the v belt pulley I brought the engine rebuilt I didn’t want to change to a new radiator as I wanted it to look semi original although it’s now an alloy radiator. So to be clear if I’m using an older style water pump now so I have the outlets on the same sides is this meaning that the water pump is spinning the wrong way and not pumping the water . ? Do I have to change belt and pulleys ? I will try to get photos today.

Offline GEOFF289

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Re: 65mustang 302 water pump issues
« Reply #7 on: March 11, 2023, 10:01:17 am »
Hi no it runs the v belt pulley I brought the engine rebuilt I didn’t want to change to a new radiator as I wanted it to look semi original although it’s now an alloy radiator. So to be clear if I’m using an older style water pump now so I have the outlets on the same sides is this meaning that the water pump is spinning the wrong way and not pumping the water . ? Do I have to change belt and pulleys ? I will try to get photos today.

Don't think that's your problem. With that pump and v belts it should be spinning the right way. To confirm, do you have an engine driven fan? If so, check that its sucking air through the radiator rather than trying to blow it back. Mind your fingers, maybe hold a bit of tissue paper in front of the radiator, if it gets sucked up to the rad it's all spinning the right way. If it blows the paper away, it is reversed but I really can't see how this could be.

If you don't have an engine driven fan, just watch which way the pump is turning with the engine running, should be clockwise as you stand in front of the car, i.e. same direction of rotation as the engine itself.

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Re: 65mustang 302 water pump issues
« Reply #8 on: March 11, 2023, 06:35:24 pm »
Hi Philip,
photos will help.
Did you say that you bought the 5.0 motor rebuilt ?
Have you only changed the water pump from the original 5.0 setup ?
Are you still running the 5.0 timing cover or have you swapped to an early style there as well?
There are some compatibility issues with running early pumps on roller 5.0 timing covers. May be as simple as finding the right gaskets or having to find an early timing cover.
When your engine is running , with the radiator cap off are you seeing any water flow when the thermostat opens ?

Regards

Offline Phillip28

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Re: 65mustang 302 water pump issues
« Reply #9 on: March 12, 2023, 03:18:07 pm »
Hi looks like a simple rookie error when we turned water pump with belt off there was minimal flow of coolent checked thermostat it’s in the right way but when I took the water pump off we noticed that because I used sealant I’ve put too much on and blocked up the coolent holes in the block I could only put my little finger in there . We are pretty sure that this is the issue so I’m ordering new gaskets and putting it back together. Any issues I’ll let you all know thanks heaps.

Offline GEOFF289

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Re: 65mustang 302 water pump issues
« Reply #10 on: March 13, 2023, 02:34:56 pm »
Glad you've got it sorted.