52000 miles, 5 yrs old, should i change the anti freeze? what should i use?? is a flush realy necessary ? or just change it? thanks, richard

 

if your truck uses dexcool...the life is 5 years 100000miles...so you are due by time. use the same gm coolant. removing the lower rad hose and water pump hose should drain 8liters. Some diy'ers use a shop vac set to pressure to blow out more coolant.

vacuum filling will a rad filler is the recommended way to fill the system. manual filling will require multiple thermocycles to get the air out of the system.

 

Use dexcool to avoid mixing issues. Get out as much of the old stuff as practically possible. It's a really easy job.

How I did it: https://chevroletforum.com/forum/exp...e4/#post430529