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Engine Coolant flow

This is a public forum to discuss Eagle related technical issues. If you are having a problem with your Eagle, this is the place to find help.
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ericbsc
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Bus Model: 1973 Eagle 05
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Engine Coolant flow

Post by ericbsc »

Tried to hook up the front heat. I put the two lines fronm the heads in and returned into the block. I turned the three valves on I thought but have no flow. How many turns does it take?
Eric Brown
Spartanburg, SC
1973 05
Series 60 allison 4000MHP
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Boomer
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Bus Model: 1981 Eagle M10. Stretched, widened, raised to M15/45 specs. Cummins ISM 450, Allison World transmission. Mid entry door.
Location: Southwest Washington

Re: Engine Coolant flow

Post by Boomer »

Try cracking the bleed cocks on your heater core. Could have air in it. Have you removed the stock 12V water pump?
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ericbsc
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Re: Engine Coolant flow

Post by ericbsc »

I replaced the entire system up front with a unit that has dash heat and air as well as defrost. I am driving an aux. pump off the engine for the air. I have the two lines coming out fron the heads connected together running to the front, and returning to the return valve on the drivers side of the engine. I do not have a pump other than the engine driven water pump. I do have a proheat system that I am installing with 12v pumps but it is not connected in this loop. I have turned those valves a bunch of times and I think they should be open. There seems to be no pressure on the new lines at all.
Eric Brown
Spartanburg, SC
1973 05
Series 60 allison 4000MHP
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rusty
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Re: Engine Coolant flow

Post by rusty »

When I plumbed my dash heat I added a 12 volt pump in the rear bay. I think that is a long way to run the lines using just the engine pump. You should still have a little water that will make it to the front but it might not be enough to push an air bubble. Also in real cold conditions I don't think you will have enough volume to heat the drivers area.

Good luck Wayne
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ericbsc
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Re: Engine Coolant flow

Post by ericbsc »

I have a couple extra marsh pumps. Seems like the factory pump would push harder than that though.
Eric Brown
Spartanburg, SC
1973 05
Series 60 allison 4000MHP
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ericbsc
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Joined: Wed Dec 24, 2008 8:31 pm
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Bus Model: 1973 Eagle 05
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Re: Engine Coolant flow

Post by ericbsc »

I put a 3.5 gpm Marsh pump clode to the engine. great flow to the front and back now. I haven't started the bus to see yet.When I took the front lines loose I had coolant in the lines but not a lot. Probably the lines in the new new unit cores are smaller also. They have restrictor valves in the lines that adjust the temp. I hope this does not cause a heat problem with the pump in back running when you turn the air temp up on the unit.
Eric Brown
Spartanburg, SC
1973 05
Series 60 allison 4000MHP
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rusty
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1994 15/45 in progress
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Re: Engine Coolant flow

Post by rusty »

I don't know anything about the marsh pump but if you are worried you can put a switch up front to turn it off when you don't need it. I have a switch up front next to the heater control. I turn it on and leave it on all the time I don't know what kind of pump I have but have had no trouble.

good Luck Wayne
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