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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-

Aftermarket coolant over flow tank

  • Thread starter Thread starter Nightstang00
  • Start date Start date Jul 27, 2019

Nightstang00

Active Member
Mar 20, 2017
133
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Jul 27, 2019
#1
  • Jul 27, 2019
  • #1
I am switching to contour fans, and got a coolant tank online from amazon. Seems to be highly rated but i filled the stock reservoir up to cold and poured it into the new one and its almost filled up. I’m concerned that it will not be able to take the hot level of fluid based off the line level on the stock reservoir.

Would I just be able to fill the raditator up and not the overflow reservoir? It’s from a 93 5.0 5 speed.

The more I think about it , I don’t remember seeing any coolant in the stock overflow tank when I removed it. The after market overflow is 800ml.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,257
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Massachusetts
Jul 27, 2019
#2
  • Jul 27, 2019
  • #2
It just needs to be sized enough to handle the expansion of coolant.

I run this one, which is 1qt.
https://www.summitracing.com/parts/sum-g1476

It still works fine even with my larger 3-core radiator and more fluid volume. Level only rises an inch or two when heated.
 

Nightstang00

Active Member
Mar 20, 2017
133
12
28
Jul 27, 2019
#3
  • Jul 27, 2019
  • #3
Mustang5L5 said:
It just needs to be sized enough to handle the expansion of coolant.

I run this one, which is 1qt.
https://www.summitracing.com/parts/sum-g1476

It still works fine even with my larger 3-core radiator and more fluid volume. Level only rises an inch or two when heated.
Click to expand...
how would I be sure if the one I have works currently ?
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,257
17,941
224
Massachusetts
Jul 27, 2019
#4
  • Jul 27, 2019
  • #4
I'm more than confident it would. Install it, run line to the bottom of tank and fill to 1" or so depth of coolant with radiator topped off.

Run engine til warmed up and note how high the coolant rises. Add coolant to bring the level up to a height you are comfortable with.

I have mine set so full hot is about 2/3 up.
 
Reactions: Nightstang00

Steel1

Mustang Master
Aug 18, 2017
1,419
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143
Connecticut
Jul 27, 2019
#5
  • Jul 27, 2019
  • #5
I've have an aftermarket overflow on my 93GT for quite a few years now.
Forget brand but it's about 2" in diameter and about 12" tall, full hot I only get about
an inch or two in the tank, seems to work fine.
 

Nightstang00

Active Member
Mar 20, 2017
133
12
28
Jul 27, 2019
#6
  • Jul 27, 2019
  • #6
Mustang5L5 said:
I'm more than confident it would. Install it, run line to the bottom of tank and fill to 1" or so depth of coolant with radiator topped off.

Run engine til warmed up and note how high the coolant rises. Add coolant to bring the level up to a height you are comfortable with.

I have mine set so full hot is about 2/3 up.
Click to expand...
Thanks man. Didn’t want anything blowing up hahah
 

Wayne Waldrep

Before I post a pic, do you have one of yours?
20+ Year Stangneter
Apr 14, 2003
1,338
659
143
Cuba, AL
Jul 27, 2019
#7
  • Jul 27, 2019
  • #7
You coolant overflow experts should tell us regular folks about why it's not good for the reservoir to be empty. I'm thinking it could eventually draw in air and mess up the system....correct? Or not? And by mess up I mean make the already inaccurate stock temp gauge read even more wonky because of an air pocket.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,257
17,941
224
Massachusetts
Jul 27, 2019
#8
  • Jul 27, 2019
  • #8
Correct. When the coolant cools, it contracts. It draws from the overflow. If the van is empty, it pulls in air.

Usually as the coolant expands, the air gets pushed back into the bottle, but not always.

Ideally, set it up so that full cold you still have coolant in the bottle. That guarantees an air free radiator
 
Reactions: Wayne Waldrep
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