Coolant overflow/reservoir tank question

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liquify33

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Are these overflow only or are they 2-way reservoirs? Will it add to a low radiator level?
I found my coolant was a bit low when I turned on the heater but the tank level did not move. I've been keeping an eye on it since I did the water pump.
 

wjburken

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Are these overflow only or are they 2-way reservoirs? Will it add to a low radiator level?
I found my coolant was a bit low when I turned on the heater but the tank level did not move. I've been keeping an eye on it since I did the water pump.

How long ago did you change your water pump?

Where are you measuring your coolant level that you are saying it is low?

I am not sure what year your vehicle is but I am pretty sure that from at least 1993 on, you check your coolant levels at the plastic tank and add additional fluid there so it would be a 2-way tank as you say.
 
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liquify33

liquify33

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How long ago did you change your water pump?

Where are you measuring your coolant level that you are saying it is low?

I am not sure what year your vehicle is but I am pretty sure that from at least 1993 on, you check your coolant levels at the plastic tank and add additional fluid there so it would be a 2-way tank as you say.


Water pump was replaced about 6 months ago. I was checking some AC systems and noticed the heater didn’t get very hot. I opened the radiator cap too soon and lost some coolant.
I added directly into the radiator afterwards and the heater now works. Reservoir level never moved during this time (a couple of days).

Could the hose be clogged or is there a screen?
 

wjburken

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Water pump was replaced about 6 months ago. I was checking some AC systems and noticed the heater didn’t get very hot. I opened the radiator cap too soon and lost some coolant.
I added directly into the radiator afterwards and the heater now works. Reservoir level never moved during this time (a couple of days).

Could the hose be clogged or is there a screen?
Might not be a bad idea to check the line going to the bottom of the plastic tank.
 

96-2D-Hoe

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Pretty sure you need to run the truck so the thermostat opens with the rad cap open to fill it up properly. Not sure if the expansion / contraction from the tank will fill the rad properly/completely. I don't think it does.
 
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liquify33

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Pretty sure you need to run the truck so the thermostat opens with the rad cap open to fill it up properly. Not sure if the expansion / contraction from the tank will fill the rad properly/completely. I don't think it does.

That’s what I did after I opened it too hot and had some coolant pop out. I was under the impression the reservoir tank would maintain the level to a certain extent but it does not appear to be working that way.

I gave it a day or two to see and the tank level never moved. So what I’m wondering is:
Is the reservoir supposed to maintain radiator level (if so, mine isn’t) or it simply just overflow to prevent over pressuring the sealed side of the cooling system?
 

96-2D-Hoe

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It's basically for expansion, not filling the rad. When my truck is hot the tank sits at the hot mark, and when cold it's down at the cold mark. I just don't think the 'overflow' tank will fill a rad that isn't full already.

Have you opened the rad cap when the engine is cold to see if the rad is full?

If it isn't top it off then start the truck and keep filling if necessary until the thermostat opens when you will see coolant rushing through and top hose will get warm. Then put the rad cap back on. It will start to overflow at the same time but that is basically the way to refill the engine and rad if I remember correctly.
 
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96-2D-Hoe

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Not sure if you did this already but here's a video where they use a sealed funnel, you basically do the same thing but just keeping the rad topped off to the top. Need to let the thermostat open fully to make sure there is no air in the engine. At this point the coolant will start to expand and will be overflowing from the rad and you just put the cap on. When it cools and contracts it should pull coolant from the reservoir to fill the rad.

 

96-2D-Hoe

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I have a coolant leak / weep from the intake manifold and so I have to add coolant to the tank, but my rad stays full.

Might also want to get a new rad cap, it is supposed to be regularly replaced.

Hope that all helped some.
 
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