Howdy Guys.....I have not had my 1998 Blazer very long and am still learning it. I lost the repair manual I bought and need to change coolant for a long drive from Washington to Las Vegas next week to get married during this years 4 day long Biker Fest.


In the past all my trucks were Non-smog trucks without all the garbage on that newer vehicles have. I had all older hot rod trucks (pre 1972) and the Blazer has things on it I am not familiar with. Watching YouTube I see everybody using a Spill Free Funnel to fill the radiator and burp it. On my old trucks all I did was fill the radiator and leave the cap off as it ran for about 10 minutes adding coolant as needed watching for bubbling to stop then installing the cap and was good to go.


Now days everybody says you must make sure to not get any air in the system and the Special Spill Free Funnel is needed to insure no air gets in the system.


My system has been neglected and is in need of a flush BUT after reading from the archives here I'm hesitant to do it because I don't want to break anything loose and clog up my heater core or thermostat etc. so I'm thinking of just draining the radiator via the petcock or if it's stuck take off the lower radiator hose. Then drain with motor running until no water comes out. Then attach hose or close petcock and fill with 50-50 mix and just burp it by leaving the radiator cap off until it comes up to temp and the bubbling stops and then put cap back on radiator.


Do you guys think this would be the safe thing to do for now. Later this winter I will do a reverse flush of the heater core and maybe even use a flush kit and remove the thermostat and keep flushing until the water comes out clean but for right now I just want to make sure there is no orange coolant mixed in with the green stuff because when it leaked from the freeze plug last month I just put in green coolant not knowing if the previous owner had used orange stuff.


I just want to make sure it gets me to Las Vegas and back to Washington without any problem.....it's 100 degrees in southern Calif right now so Vegas will be hot too!


Thanks Guys
Patrick
Skagit County, Washington
1998 Blazer LS 2whl drive

 

Honestly, I would rent a late model car for the drive to Vegas. Then, I would worry about flushing the cooling system. I might even replace the radiator and thermostat after flushing...

 

Orange or Green, your choise. What you really dont want to do is mix the two. Really!

 

Dexcool (Orange) is original and has a longer service life than Green. Green will work if you change it more often. Mixing the two gives you a shorter lifetime than either has by itself. Myself I have chosen to use GM Dexcool in my Blazer.

If your cooling system has problems where the level keeps going down/air gets into it - then it needs fixed (not a switch of antifreeze type). Unfortunately, few ever change antifreeze on a schedule. Then the additives get depleted and bad things happen.

Radiators in our Blazers work all air out of the cooling system by replacing air with coolant from the reservoir during temperature cycles.

When filling a completely dry radiator and engine, I simply jacked up the front end using a floor jack and filled the radiator slowly to the top of the neck, topped it off as necessary to keep the level there, put the cap on, filled the reservoir to the hot mark, and then kept adding to the reservoir over the next week until the level stabilized.

 

I agree 100% with CWBDDSPC. Put the miles on a rental. What I do for long trips 1000+ miles.

 

I learned the hard way that you do not want to mix green with Dexcool (orange). They don't get along and basically turn into mud. I had that happen when I put a junk yard engine in my blazer. I didn't get all of the dexcool flushed out and they mixed and my car overheated when it was -2 degrees out. Here is what I did. I bought 6 gallons of distilled water and some Prestone coolant flush. Drained all of my coolant out, removed the thermostat and filled it with the flush and then filled it with water and drove it for a couple of days. Then I drained that and filled it with distilled water again. Then drove it for about a month on just water (it was ok in the summer). Then I drained that, put a new thermostat and filled it with 50/50 green coolant and so far it has been fine. I will probably do another spill and fill before winter just to be safe.

 

After completely flushing the crud out of my system I filled it with Prestone that mixes with any coolant. Over a year later it's still clean and I've had no problems.

 

I replaced my water pump a few days ago, and I wish I had bought that no spill funnel, wasted probably half a gallon of antifreeze in the process. Was my first time opening up the system, so I had no clue what I was doing aside from the info I got on here and youtube.

I'm sure someone will point out something I did wrong, but this is how it went. After reattaching all my hoses and getting everything buttoned up, I filled the radiator as much as I could with half distilled water half Dex. Left rad cap off, jacked up front passenger side of the truck and started the engine with heat on full blast. After a few minutes coolant/air was spilling out the fill neck, made sure I had catch pan underneath. I was keeping an eye on the temp and it started to creep up to past 220 degrees. I got nervous and shut the truck off, but then noticed that the upper radiator hose wasn't hot, so the thermostat hadn't even opened yet. Also air coming from vents wasn't hot. Started truck again, temp was still very high, but then the tstat must have opened soon after, since the temp immediately dropped to the normal range. Also coolant level in radiator dropped quite a bit, so I added more until it was full. Kept truck running until no more air/coolant burped out. Took it for test drive at different speeds/conditions, temp never went above 192. Seems to have been successful.

So yeah, unless I did something really wrong here I wished I had that special funnel so I didn't waste so much coolant.

 

Sounds to me like you had a lot of air trapped in the system which finally made its way out. And yes, that spill proof funnel is totally worth it.