Antifreeze Disappearing

Hey Everybody

Got a question about my 96 Blazer. Has 74,000 miles on it and of course has good old dexcool. Anyway, I changed the antifreeze in it about a month ago and have had to put like 2 gallons of 50/50 dexcool and water back in this thing. I am not really sure if it is leaking it but I have noticed that there is a lot of leakage around the oil filter door which leads me to believe it is leaking antifreeze from somewhere. I'm pretty sure it is mainly antifreeze leaking around there even though the oil cooler lines leak a little bit. Maybe the radiator is leaking above it because I really can't tell from the top of the engine. Could this be a problem with the radiator cap being an AC delco. When I went to get a new 15lb Stant, all they had was 16lb or Delco and I definately do not want the Ac Delco cap. Also the antifreeze that I put in was actual GM dexcool that I bought at a swap meet that was brand new and only like 3 bucks a gallon. Should I reflush this thing and put in the Prestone Dexcool or maybe even that mix with any type coolant stuff? Thanks for your help!

It may be your water pump. There's a weep hole on it for when the bearing gives out. This might explain the leakage around the oil filter door. Open it up and look up at the pump to see if there's moisture around it.

if you have access to a pressure tester will help a lot.
Check at the therostat housingm, my 2002 full size was leaking there had to let run for a few minutes to see the leak after it got hot it evaporated

Make sure the drain plug is fully closed.

The 16lb Stant is fine, that's what most of us get.

Sounds like the water pump to me.

Yup I agree, sounds like the water pump may have let go, mine did in my 98 around 85K. I have had so much work done to this thing that it better last me 200K!

When the seals go, coolant will go out the weep hole.

Yeah I had to replace it in my 71 Monte Carlo when it was leaking out the weep hole. Would that explain coolant around the oil door? I really can't tell if it is coming from the water pump because everything is so crammed in this thing. Also this problem of disappearing coolant did not happen until after I changed the coolant, at least not as much as I have had to put in it. Thanks for the help.

You are aware that after changing the coolant, it takes a while to work the air out of the system. Everytime you get it up to temperature and then let it cool a little air is removed.

I would think after a month though and nearly 800 miles or so it should be worked out by now. I changed my Explorers and only added a little bit later the same day and that was weeks ago and it was fine. Guess Blazers are more finicky.I'll keeep you all posted.