How much coolant does the coolant system hold?

Hi,

Interestingly, less than 80% of the engine coolant can be drained with the engine in the vehicle. See pic 1 below.

As far as capacity, it does hold over 4 gallons total. See pic 2. What I can tell you is to drain the radiator, disconnect the lower radiator hose, and then allow it to drain. There used to be a plug on the engine block to drain the coolant from it, but from what I'm seeing, this doesn't have one.

Take a look at this link. There is a video of the service being done on a Ford 3.5L.

https://www.2carpros.com/articles/coolant-flush-and-refill-all-cars

Let me know if that helps.

Joe

See pics below.

I drained the radiator and got only 1 gallon of antifreeze, how can I drain the whole cooling system? I know it holds at least 4 gallons of coolant.

Hello,

From the factory there is 16.5qts put in the system to fill it up. A lot of that is retained in coolant passages, hoses, heater core, etc., and simply won't come out.

One way to get a bit more would be to elevate the rear of the truck up as high as you safely can. This may allow more coolant to end up towards the radiator and out the drain petcock.

Also, you can use a pressure tester to pump air into the system to help move the coolant through the system. If you have a pressure regulator and can make up the right adapter, you can pressurize the system to no more than cap pressure to assist in purging the system.

My experience with these trucks is you'll be lucky to get half of the full capacity, so be careful you refill with the same type or compatible coolant.

Let me know if you have any questions!

Thanks,

Jason