Leaking Radiator/new fluids

[chuck will]

I have been told that the old radiators if used with the newer coolants
there is a chance of leaking, due to the new type of fluids used and
they are not compatible with the way the old radiators were put
together. Is this a truism? Chuck in Lompoc

 

[wayne newland]

Chuck

Until about 5 years ago, I taught mechanics to use Wynn's cooling system
programs. The secret is to use a 50/50 mixture of anti-freeze and water,
Wynn's Cooling System Additive (to keep the additives alive for as long as
people think their anti-freeze should last - about a year) and a can of
Wynn's Stop Leak.
Now DON'T USE JUST ANY STOP LEAK. Some will really screw up your system.
Pressure check the system when you are done, and don't be surprised if you
find a small leak somewhere. So my answer is - the new stuff works in the
old stuff if the old stuff isn't rotten to begin with.

Wayne Newland F9300 75 Plam Beach

> I have been told that the old radiators if used with the newer coolants
> there is a chance of leaking, due to the new type of fluids used and
> they are not compatible with the way the old radiators were put
> together. Is this a truism? Chuck in Lompoc

 

[brent covey]

Chuck wrote;

>I have been told that the old radiators if used with the newer coolants
>there is a chance of leaking, due to the new type of fluids used and
>they are not compatible with the way the old radiators were put
>together. Is this a truism? Chuck in Lompoc

Probably not-

We've been using DexCool (the orange long life stuff made for GM by Texaco)
since it was first availible in cars back to 1960 models with good results.
If you read the disclaimers regarding older systems it is clear that there
is nothing in the new product that will damage your cooling system, but that
previous faults and damage may become evident. The old green coolants coated
everything and this would possibly conceal a fault- the new products are
somewhat more inert and do not coat things nor react to much. The REAL
advantage of the new DexCool is alauminum parts will not be apt to corrode
at anything approaching the rate they used to.

I would not be shy about using the DexCool at all.

A few notes about it-

We have found it seems to work best at a slightly stronger mix, like 60%
rather than 50/50. I always flush the cooling system very thouroughly
(overnight) with a trisodium phosphate type cleaner, (you can make your own
or buy 'rad flush' from a company like Wynns etc.) and then replace all the
hoses and the hot water valve + thermostat.

If you are worried about small leaks on a very marginal system, you can use
the Cadillac HT4100 tablets in your coolant. These are availible at any GM
dealer for $5 or so, and are made from some kind of spice primarily
(tarragon?) . They look like Horse Pills. I don't really recommend them as
they are kind of messy, but they are safe and will stop small leaks.

DexCool prices vary widely- phone around for the best price, the dealers
usually charge the most and the AC Delco Jobber warehouses the least.
DexCool is more costly than regular antifreeze, by about 100%.

Bear in mind, DexCool is compatible with older coolants, you can mix them or
top one up with the other, but this makes it extremely hard to test
strength. Try not to mix them if possible.

Even with DexCool, you'll need new radiator and heater hoses every four
years same as ever before! The coolant might last forever, but the rubber
parts surely won't. Perhaps one day we'll get silicone hoses for the GMC's
made and be able to see ten year service intervals.

The DexCool has much to recommend itself in seasonally used MotorHomes also-
Silicone dropout is not a consideration as it is with the older coolants. No
more gunk!

Anyhow, I would use either coolant, the DexCool may prove to be a worthwhile
improvement if the extra cost does not bother you. I certainly would not
expect any problems related to use of DexCool type antifreezes. We have
certainly had good experience with it.

Good Luck!

Brent Covey

 

[bartz paul]

Many of the 94-96 Chevy Impala SS owners report that they are experiencing
heater core plugging problems with the DexiCool coolant that was original
with the vehicle.

Paul Bartz

From: Brent Covey [mailto:deville]
Sent: Sunday, July 11, 1999 11:39 AM
Subject: Re: GMC: Leaking Radiator/new fluids

Chuck wrote;
I have been told that the old radiators if used with the newer coolants
there is a chance of leaking, due to the new type of fluids used and they
are not compatible with the way the old radiators were put together. Is
this a truism? Chuck in Lompoc

Probably not-
We've been using DexCool (the orange long life stuff made for GM by Texaco)
since it was first availible in cars back to 1960 models with good results.
If you read the disclaimers regarding older systems it is clear that there
is nothing in the new product that will damage your cooling system, but that
previous faults and damage may become evident. The old green coolants coated
everything and this would possibly conceal a fault- the new products are
somewhat more inert and do not coat things nor react to much. The REAL
advantage of the new DexCool is alauminum parts will not be apt to corrode
at anything approaching the rate they used to.
I would not be shy about using the DexCool at all.
A few notes about it-
We have found it seems to work best at a slightly stronger mix, like 60%
rather than 50/50. I always flush the cooling system very thouroughly
(overnight) with a trisodium phosphate type cleaner, (you can make your own
or buy 'rad flush' from a company like Wynns etc.) and then replace all the
hoses and the hot water valve + thermostat.
If you are worried about small leaks on a very marginal system, you can use
the Cadillac HT4100 tablets in your coolant. These are availible at any GM
dealer for $5 or so, and are made from some kind of spice primarily
(tarragon?) . They look like Horse Pills. I don't really recommend them as
they are kind of messy, but they are safe and will stop small leaks.
DexCool prices vary widely- phone around for the best price, the dealers
usually charge the most and the AC Delco Jobber warehouses the least.
DexCool is more costly than regular antifreeze, by about 100%.
Bear in mind, DexCool is compatible with older coolants, you can mix them or
top one up with the other, but this makes it extremely hard to test
strength. Try not to mix them if possible.
Even with DexCool, you'll need new radiator and heater hoses every four
years same as ever before! The coolant might last forever, but the rubber
parts surely won't. Perhaps one day we'll get silicone hoses for the GMC's
made and be able to see ten year service intervals.
The DexCool has much to recommend itself in seasonally used MotorHomes
also-Silicone dropout is not a consideration as it is with the older
coolants. No more gunk!
Anyhow, I would use either coolant, the DexCool may prove to be a worthwhile
improvement if the extra cost does not bother you. I certainly would not
expect any problems related to use of DexCool type antifreezes. We have
certainly had good experience with it.
Good Luck!
Brent Covey

 

[richard waters]

Paul,
I didn't know about this "even with DexCool, you'll need new radiator and heater
hoses every four years same as ever before! The coolant might last forever, but
the rubber parts surely won't."

Another thing to do, but then I might get a new engine before too long.
I have about 130,000 miles. I don't know how long it will last, but maybe
I should change it out in a few years. That way I would also get new hoses.

BTW I won't be going to Oshkosh this year, I have some business stuff to
do before I go on vacation (in the GMC I hope) next Saturday.

Richard Waters '76 PB, Troy, MI
- ---

> Even with DexCool, you'll need new radiator and heater hoses every four
> years same as ever before! The coolant might last forever, but the rubber
> parts surely won't. Perhaps one day we'll get silicone hoses for the GMC's
> made and be able to see ten year service intervals.
> The DexCool has much to recommend itself in seasonally used MotorHomes
> also-Silicone dropout is not a consideration as it is with the older
> coolants.