Transmission Cooler

dna9656 · April 3

I have 2015 Silverado LTZ 4 door, 4 X 4. I have RPO code KNP Transmission Cooler. Now the "cooler" most automatics have is a pipe in the radiator tank and there is no code for that; it's part of the Transmission standard equipment. Can I assume this is a separate cooler (like a little radiator?) Where is it? I see nothing like a GM tranny cooler I have seen on the '04 S 10s... I looked through the grill....

rav3 · April 4

I'm not sure about your '15 but my '17 LTZ wt 5.3L & 6 speed 6L80 has the cooler intergrated into the top potion of the A/C condensor. No separate cooler like in the past and there is a transmission thermostat valve on the side of the transmission, which I disabled via the 'pill flip'.

newdude · April 4

1 hour ago, dna9656 said:

I have 2015 Silverado LTZ 4 door, 4 X 4. I have RPO code KNP Transmission Cooler. Now the "cooler" most automatics have is a pipe in the radiator tank and there is no code for that; it's part of the Transmission standard equipment. Can I assume this is a separate cooler (like a little radiator?) Where is it? I see nothing like a GM tranny cooler I have seen on the '04 S 10s... I looked through the grill....

2015 will go transmission to radiator, radiator out to the aux cooler that is part of the AC condenser then back to the transmission.

Should look like this:

Enters bottom driver's side of the rad from the out flow line, flows to the top and exits at the top out to the aux via #14, then comes out of pipe #5 in the drawing and connects back to the transmission input line.

rav3 · April 4

32 minutes ago, newdude said:

2015 will go transmission to radiator, radiator out to the aux cooler that is part of the AC condenser then back to the transmission.

Should look like this:

Enters bottom driver's side of the rad from the out flow line, flows to the top and exits at the top out to the aux via #14, then comes out of pipe #5 in the drawing and connects back to the transmission input line.

Are the '17s like this?

newdude · April 4

11 hours ago, rav3 said:

Are the '17s like this?

No. They only use the condenser combi cooler for cooling the transmission. They removed the radiator from the cooling path. When you pill flip or surecool these, they run much cooler than the 14-16 trucks above. Struggle to get above 100-110F in the winter, 130-145F in the summer (on a known good transmission that isn't slipping). Mine wouldn't get over 100F in the winter, summer I could beat the snot out of it on a 90 degree day and wouldn't break 145F.

2016.5-2019 classic/LD:

rav3 · April 4

Where are u finding the parts alliteration?

dna9656 · April 5

On 4/3/2024 at 5:57 PM, newdude said:

2015 will go transmission to radiator, radiator out to the aux cooler that is part of the AC condenser then back to the transmission.

Should look like this:

Enters bottom driver's side of the rad from the out flow line, flows to the top and exits at the top out to the aux via #14, then comes out of pipe #5 in the drawing and connects back to the transmission input line.

My cooler lines go to the side tank closest to the engine; I believe that's the radiator as i have never seen a condenser with side tanks like a radiator does. Pics later today.

newdude · April 5

1 hour ago, dna9656 said:

My cooler lines go to the side tank closest to the engine; I believe that's the radiator as i have never seen a condenser with side tanks like a radiator does. Pics later today.

Look at that picture again. Condenser, the top 1/5-1/4 of it is the transmission cooler. The rest of it is all for the AC operation. Its called a Combi Cooler. All of the V8s 14-19 use this.

Douglas Nathan · April 5

32 minutes ago, newdude said:

Look at that picture again. Condenser, the top 1/5-1/4 of it is the transmission cooler. The rest of it is all for the AC operation. Its called a Combi Cooler. All of the V8s 14-19 use this.

So then there's NO WAY I can have engine coolant in my tranny fluid?

As you can see, I have no more white streaks. I have beautiful transmission fluid!

Edited April 5 by Douglas Nathan

newdude · April 5

6 minutes ago, Douglas Nathan said:

So then there's NO WAY I can have engine coolant in my tranny fluid?

You could if the radiator is leaking into the transmission cooler tank in the radiator.

That just looks like old ATF. does it smell like coolant?

Edited April 5 by newdude

newdude · April 5

2 minutes ago, Douglas Nathan said:

So then there's NO WAY I can have engine coolant in my tranny fluid?

Direction of flow for 14-16 V8. Transmission to radiator tank side cooler, out to the condenser combi cooler, back to the transmission.

dna9656 · April 8

Well, I have not seen what's shown here, Just what you can see from the engine side of the radiator when it's all installed. The fluid is a week old, it's Dexron VI filtered through an AC Delco tranny filter. I hope to get a Purolator filter (they are the finest filtering filter on the US market (except for maybe Amsoil by-pass filter); It's hard to find a Purolator dealer, Tractor Supply Company is one, I assume the Purolator name is well known in the farming community. Anyway...Thanks for your input and for clarifying what I have in my new to me truck!