dex-cool in a 49?

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i am planing about using dex-cool( the red anti freeze) in my 49 roadmaster is it going to be a problem?

[BUICK RACER]

Don't do it, the red stuff will eat the brass heater and any thing else away, in fact even on the new cars it is put in are having problems if they are not driven all the time, do a search on this board, look for info from NTX5467, Willis, he works in a dealership in TX and has put on the board here some very interesting info on the DEX COOL stuff. RV

[NTX5467]

Dexcool did appear after the lead was out of the cooling systems (i.e., solder that seals the tanks on the radiator and heater cores), but I don't think it will harm the brass or copper. From what I discovered, you MUST use it in a closed cooling system with coolant recovery system--period--and you have to keep the radiator full all of the time with that system and have a good, quality radiator cap on the radiator. Otherwise, you have the same problems that many late model S-10s had with it corroding up the filler necks and such.

A better alternative might be the Rotella Extended Life coolant for over-the-road diesels. It's not Dexcool but does have extended change intervals. I read about it in one of the editorials in Car and Driver a while back. You can check it out on the web in the Shell website and see what you think. Our local WalMart has it in the 50-50 premixed version with details on how to use it on the bottle.

In reality, paying more to use less is not very good considering a system that has already had regular green coolant in it is not recommended to go past about 50,000 miles on the change interval with Dexcool. You can find those things out on the Texaco website and also probably on the back of the Dexcool bottle.

Considering that, you're better off to use the existing low silicate green coolant of a good brand and continue as you have in previous times. Dexcool is designed to work only in the vehicles for which it came in from the factory, where the original factory fill was with Dexcool and had recommended change intervals of 100,000+ miles. Using it in a system that came with green coolant will not be really cost effective or beneficial.

Possibly the only way Dexcool might be an option would be with a completely new/rebuilt motor, new radiator, new heater core, new radiator cap, and new rubber hoses PLUS the coolant recovery system I mentioned. Still, I think I'd stay with the existing green coolant even with all of that stuff being fresh and new and such. Other than the longevity in the new cars, Dexcool has no other real benefits. The silicate free formula might extend the life of water pump seals, as they mention, but we're still selling water pumps at 70,000-100,000 miles on some vehicles as in the past.

Thanks for the comments, Roberta.

Enjoy!

NTX5467

[NTX5467]

The one "trick" thing that Dexcool does, from what I've read in GM service literature, is that during the first 3000 miles of use in a new vehicle, it chemically coats the entire cooling system with a corrosion preventative. With that issue taken care of, the other differences in the Dexcool formulation can be utilized to their fullest extent and also allows the silicates to be removed (which is claimed to affect water pump seal life).

If someone mixes regular green coolant with Dexcool, it compromises all of the Dexcool benefits and the system needs to be completely flushed and returned to the previous Dexcool formulation as soon as possible. We have seen some systems where people have not maintained them at all, adding green on top of orange as they either didn't know better, didn't care, or couldn't afford Dexcool. If the system is continuously operated "low" on coolant, the same situation as we had with the S-10s comes into play except it looks like a cooling system full of mud. To get past that, then a chemical coolant flush procedure needs to happen and things put back "right" with Dexcool.

To my knowledge, GM has never publicly stated that Dexcool could be used in earlier vehicles than which it came factory equipment in. Texaco, on the other hand, stated early on on their website, that if you flushed the existing system with clean water TWICE, then you could use Dexcool but only with a 50,000 mile change interval and NOT the 100,000+ miles interval on the GM vehicles it came from the factory with. That was before the issues of maintaining the correct coolant levels at all times and having good radiator caps had surfaced in the field. Even though the system was fully purged of the green coolant, there apparently is enough residual coolant that has permeated the inner surfaces of the enigne block and other items it has touched to compromise the ultimate benefits of the Dexcool coolant (i.e., longevity).

We sell "aftermarket" Dexcool for about $12.00/gallon and green "aftermarket" coolant for $7.50/gallon. In both cases, the genuine GM items are more expensive, but still in about the same proportion. Paying the extra premium to use Dexcool in an older system with very little extra change interval extension recommended in that situation, for no real benefits, seems a little strange--but the observed service and engineering reasons for not using Dexcool in a vehicle it did not come from the factory with (unless the vehicle might have a completely new--not used--engine, radiator, heater core, and other stuff as I mentioned perviously--with a properly maintained CLOSED coolant system and recovery jug, which would approximate the same conditions as a new car would have in those situations) are the main reasons for not using Dexcool in those non-factory applications. Dexcool is still an Ethylene Glycol formulation and offers no increase in freeze protection over any other coolant, regardless of dye color.

Adding a working coolant recovery system to a vintage vehicle would probably take points from it in car show judging situations. Keeping the radiator constantly full when cold would result in unsightly "puking" from the existing radiator overflow tube plus the deposit accumulation in the radiator tank near the filler neck with time, possibly. End result, you can create your own problems by trying to use Dexcool in an earlier vehicle or not keeping the coolant recovery jug full in a late model vehicle it came in from the factory.

I hope that further clarifies those concerns for you.

Enjoy!

NTX5467

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i am glad i ran into a problem with my cooling system other wise i would have used the dex cool

thanks for the advice

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