Radiator i flushed the radiator and added one gallon of antifreeze/collent but i do not know the size of the radiator and i fear that was not enough antifreeze/collent and my truck keeps over heating.

Question moved from Spanish Car company Seat (pronounced See-At).

That's hilarious and the very first time this has been posted on Fixya in my 12 year term with nearly 50,000 questions answered!

Well it will smell nice, but won't do much for it antifreeze capabilities. Did the cooling system take the whole gallon? That is a lot to be under-level! As it is new to you, it would be a good opportunity to drain the system and do a flush and a top up with new antifreeze and demineralized water. It is fairly easy once you find the drain on the radiator.

Google

year make model coolant flush

You also have to burp the system of air which is covered in a Tip I wrote.

https://www.fixya.com/cars/r29872074-vehicle_cooling_system_no_heat

'year make model' should be the first three words in every question please Also the Fixya scripting will usually offer you the correct category..

First why are you adding it are you overheating? Just a question here for a regular coolant change after you add it you must run the engine to circulate it but when drain it if you didn't drain the engine also there's still fluid in there and that's why only a little bit did you remove the coolant bottle cap when draining it ? Also you obviously had the car jacked up so this raises the engine on an angle keeping a lot of fluid in and you need to remove the lower hose for it to come out on level ground

as there will be little coolant left in the block
the antifreeze will be in the ratio of 50:50 to water that is added to the radiator
so if the system is 5 gallons that will be 2.5 gallons of antifreeze to 2.5 gallons of water

It depends on where you live. If it doesn't get below 10 F, one gallon of antifreeze will do. Then fill it the rest of the way with water. If you measure how much of water added, there is a table of temperatures on the bottle to let you know your protected temperature.

Check your oil level to make sure it is not mixing in with the antifreeze you may have a blown intake.

Did you do the flush and fill yourself? did you put pure antifreeze in with distilled water at a 50/50 ratio? If your antifreeze mixture is pure or almost pure antifreeze, then it will not transfer your heat and will not heat the cab well at all.

If you've added two gallons of antifreeze, you need to find out where it's going. Make sure the antifreeze you are adding is diluted with water in a 50/50 solution. Pure antifreeze has little freeze protection and boils quickly. If there is no visible leak, check your oil for coolant contamination. Fill the radiator and leave the radiator cap off. Put the heater controls on hottest setting, but do not turn the heater on. Start the engine and watch the coolant. If the coolant level drops, add more to full. If the coolant is flowing thru the radiator when you first start the engine, the thermostat is stuck open and needs to be replaced. If the water is not flowing, then keep an eye on it and wait for the thermostat to open. Add antifreeze to keep the radiator full. Look for air bubbles or lots of foaming in the coolant. That would indicate a blown head gasket and the reason you are losing antifreeze. If there's no bubbles, and the coolant level stays full, put the radiator cap back on and see if the heater is working better.

On the 4 cylinder you will need 1 1/4 gallons of antifreeze mixed with an equal amount of distilled water for a 50/50 mix. On the V6 you will need 1 5/8 gallons of antifreeze mixed with an equal amount of distilled water for a 50/50 mix. Make sure and use the correct type antifreeze.

It will need as much as it takes, which is impossible to tell depending on how you flushed it.
But your whole system takes more than 2 gallons, and since you want a 50/50 mix you know you will need more than one gallon of antifreeze. So you need to start by purchasing 2 gallons. If you have left over, it does not go bad. And if you do not quite have enough, you can probably add a little extra water because you probably did not flush all the antifreeze out.
Once you run it, then next time it will need more again after the heat bleeds the air out.

Drain plug is on the bottom of the radiator. Should have a tab for the plug. PLUG DOSN'T COME ALL THE WAY OUT, you're only able to twist it so far. IF your confused, just undo lower radiator hose and have a big bucket. The anitfreeze you put in your car has to be a TOTAL mixture of 50/50. You can buy premixed 50/50 for a HIGHER price! If you don't want to pay that much, you can get STRAIGHT ANTIFREEZE. If you have an extra gallon jug around the garage, fill half with water and half with STRAIGHT antifreeze and tada! You got 50/50 antifreeze. Hope this helps ya.