coolant changeover, and water pump question

[mattt]

I have picked up a replacement ACDelco water pump 251-743 for my 04 Tahoe 5.3. I know with the previous gen trucks, the Dexcool was doing a number on intake manifold gaskets. That is not a concern with the dry intake of the 5.3, however, I'm still considering switching away from Dexcool. Anyone else switched away from Dexcool with good results? Or with bad results and then switched back to Dexcool? I spoke to a local radiator shop and they can't say anything good about Dexcool. Looking for opinions on which coolant to put back in when I do the water pump.

Water pump question.....for the life of me I cannot find the weep hole on this new water pump. Do all GM AC Delco pumps have the weep hole? The one I have is 251-743.

Any other suggestions to watch for when doing this job? If I'm not going back with Dexcool, I'd like to drain the block. Does the 5.3 block have drain plugs like previous gen SBC and BBC?

 

[mattt]

Am I really the only guy who has considered switching away from Dexcool Orange crap coolant?

 

[M1Gunner]

I run the prediluted dexcool but still mix that 50/50 with distilled water and I, knock on wood, haven't had any issues.

 

[SnowDrifter]

I like the yellow long life universal stuff. Seems to give the least problems

 

[brasil]

you do not need to drain the block...you need to flush the whole system for 15 minutes or so...with your garden hose. After you drained the coolant - of course.

But why do you want to change the antifreeze ..? Is that DEXCOOL so bad ? All of my frieds that drive Chevys use this Dexcool stuff nobody has issues.

If you buy the prediluted Dexcool you don´t have to use "water"...because I you do so... the pretection isn´t 100% anymore. This stuff is not only a antifreeze..it is a rust protector, a lubricat and it rises the boiling piont of the coolant !

 

[mattt]

Dexcool is pretty corrosive, which is why I'm looking at switching from it to something better. Plenty of reading on the interwebs about the problems with Dexcool.

No one else seen a factory GM water pump without weep hole? I'll post a pic later today.

Thanks for the suggestions.

 

[mizzouguy]

I flush my dex-cool and refill with fresh every 50k or so. Never had an issue with corrosion on my personal truck...on the other hand, have seen an 1500hd work truck with the 6.0, opened the hood at 200k with it never having anything changed fluid wise except oil and the coolant had just about eaten the tranny cooler lines out of the radiator. Looked like bad battery acid corrosion. I think as long as you change it out fairly often you are fine. It was designed for use with our engines...the engineers at gm get paid more than me for a reason lol. I'm not going to argue with them.

 

[sefiro]

There are writeups discussing the chemistry of antifreeze. In general, various elements cause the fluid to break down into stuff including acids. Dexcool contains a buffer to minimize the acid properties. But eventually the buffer will get used up and the acid will start eating things , thus the need to flush and add new antifreeze on some periodic basis.

Old green had to be flushed every 24/24k as it had no buffer agent or long lasting buffer agent

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[Chubbs]

There are writeups discussing the chemistry of antifreeze. In general, various elements cause the fluid to break down into stuff including acids. Dexcool contains a buffer to minimize the acid properties. But eventually the buffer will get used up and the acid will start eating things , thus the need to flush and add new antifreeze on some periodic basis.

Old green had to be flushed every 24/24k as it had no buffer agent or long lasting buffer agent

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I have a different vehicle that I have owned longer which runs on Dex, factory-fill, manufacturing specs. I did drain/flush that truck and refilled with typical green ethylene glycol; it is a completely aluminum engine block & cyl heads setup. The original Dex did a number on the cooling system (W/P, H/G, hoses) so I had no reservations switching it to Green ethylene. I have been running it over 2 years now with no issue whatsoever. I would have zero reservation running the Ethylene glycol in this iron-block GM truck. I haven't owned mine long enough to mess with the cooling system but I would most likely switch over.

Do you know the exact type of coolant in your vehicle? I'm pretty sure a lot of your reds & oranges on the shelf like Pentosin are just as safe the tried-&-true green ethylene glycol. It was just the name brand 'DexCool' who was garbage. Depending when & who got into your system last, you may not even have it. Either way, green or quality red Shell Rotełla, Pentofrost, Zerex but nothing with 'DexCool' on it. I have dealt with the real world repercussions of that.

 

[95escahoe]

I'm at 162k on my 04 6.0 Escalade and still use the Dexcool, aslong as you change it out when your supposed to you'll be fine, back when it first came out alotta people wouldn't change it when they were supposed too and on some of the older GM engines it would cause all kinds of problems GM actually reformulated the Dexcool years ago


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