Is is true that antifreeze loses it's effectiveness?

Yes antifreeze only last's so long, as far as I know there is 2yr or 5yr antifreeze

Yes that's one reason it's a great idea to have an anti-freeze tester handy bec it not only checks what temperatures the anti-freeze is good for best also if it's any good or not too.

It's not that hard to do yourself takes a bit of time and you could buy a flush kit at some auto parts stores that will help you , plus it be a not bad idea to have a proper anti-freeze tester handy , new thermostat gasket and thermostat , plus the right factory recommended coolant.

No1 get a few drain pans etc , open the rad drain plug and once all the coolant stops coming out close the valve , add warm tap water to the rad or over flow container until full.

No2 start the engine allow it to run until warm then turn on the heater blower until steady heat comes out for a min or so and turn off car.

No3 Drain the rad again fully then close the valve again and add the chemical flush that you can buy for rads etc and water until full.

No4 Start the vehicle and allow for it to run at least 5 mins always keeping an eye on the temperature gauge, then shut it off.

No5 Now add disstilled water to the system and start the vehicle for the water to circulate again , then turn engine off and redrain rad and keep doing this until all clear distilled water comes out of the rad.

No6 Refill the rad or over flow with a 50/50 premixed anti-freeze mixture and check your owners manual for the specs on the coolant too.

No7 Keep rechecking and adding anti-freeze as you let it on a bit off and on.

No8 You may need to remove air bubbles or air clogs via an air breather valve" looks much like a air valve on a bike or car" found on some vehicles by the thermostat housing area by opening it up and closing it once you see only coolant coming out but I'd repeat this a few times once engine has run and a bit and after a drive and allowing the engine to cool down quite a bit first. Also you can simply remove the air via removing the rad cap or over cap start up the engine a bit , stand back and wait for the coolant to push out the bubbles.

Hope that helps and best of luck.By the way some auto parts stores have diagrams or instructions etc they can print out on certain jobs and also a good service manual for that vehicle might help you too.Just keep in mind please that anti-freeze to animals is very sweet and deadly so use a proper oil absorbing materials on any coolant that has spilt , it's much like sawdust that you can buy.

Yes and no. I have never heard of any anti freeze losing its ability to not freeze if mixed properly with water. However the chemicals that protect the metals from corrosion does deteriorate over time. You can usually tell if it is getting bad by the color. If it looks dirty or starts to look dirty, it is definitely time to change it or you could have oil getting into the antifreeze.

In your case, it depends on how old your vehicle is, how the antifreeze looks and how the antifreeze tester shows as far as proper mixture. A lot of shops take advantage of anyone who doesn't know cars. You need to find and go to a shop you can trust.

Yes, but you can do it your self. There is usually a drain at the bottom of the radiator, just open it up, drain fluid, and add more. Then all you have to pay for is the anti freeze. Watch out for pre diluted anti freeze, you get half as much anti freeze as the regular bottle and it costs the same. Get a regular bottle and add your own water. Your owners manual will tell you how much it needs. You should always equal up antifreeze with water 1 gal anti freeze=1 gal water. And yes, they are always trying to get more money.

if you keep adding water to it then yes it will get weak.