F L U I D

 

 

Sometimes when replacing fluids in your car, it is impossible or impractical to completely drain the system and replace all the fluid.  An example is draining and refilling the coolant.  Or draining and refilling an automatic transmission.  With the coolant, you could just drain and refill the radiator.  The question is, how many times would you need to do that before all the old coolant is completely replaced?  Theoretically there would always be a fraction of old coolant remaining, but in practical terms after you have reached 90% you can consider the job done.

If the maintenance schedule in the owners manual says that the coolant should be replaced every 24 months, how often should you drain / refill the radiator in order to achieve that?

FLUID will calculate the percentage of fluid replaced with each drain / refill, and will also let you know how often to do it.

Here's what you need to know in advance:

 

  1. The total system capacity, which is stated in the owners manual.

 

  1. The amount of fluid that gets replaced each time you do a drain / refill.  Simply drain the system, and record how much fluid it takes to refill it.   

 

  1. The interval for replacing all the fluid, as stated in the maintenance schedule in the owners manual. Enter the interval in months.

 

  1. The target percentage for how much fluid must be replaced before considering that the job is complete.  You can accept the default value of 90%, or you can change it.

 

Important: The total system capacity and the amount of a drain / refill should both be in the same units. It doesn't matter whether you use pints, quarts, gallons, etc.  Just make sure that both numbers are in the same units. So if you enter the total system capacity in quarts, the amount of a drain / refill should also be in quarts.

After entering your data the program will show how much of the old fluid gets replaced with each drain / refill, up to the point where 90% (or whatever per cent you choose) of the old fluid has been replaced.  It will then let you know how often to do a drain / refill in order to get the fluid replaced within the interval you entered.

The math is a little more involved than you might think.  Here is an example:

Cooling system capacity = 18 quarts
Draining the radiator = 4 quarts

If you drain and refill the radiator, 4 quarts will be replaced.

4 quarts / 18 quarts = 0.222

0.222 x 100 = 22.2%

So 22.2% of the coolant has been replaced.  Easy enough.

OK, now you run the engine to mix up the coolant, and then immediately drain and refill the radiator again.   When you do that, you will be removing some of the old original fluid and also some of the fresh fluid you had just poured in.  You will not be replacing 22.2% of the old fluid -- it will be something less than that. With each successive drain/refill, you will be replacing less and less of the old fluid.

 

 

Download FLUID

 

 

You can try downloading just the program file:

 

FLUID.exe

 

If the program does not run, then it is because you need some additional files.  Delete the program file and then download the installer.  The installer will install all required files.

 

FLUIDinstaller.exe

 

 

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