2013 Z71 Suburban additional transmission cooler

[jeffm333]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

 

[Geotrash]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

They took a shortcut. They should have replaced your radiator and cooler lines as part of the job. You're right that it needs be plumbed in series with the radiator. You can replace the radiator yourself if you wish and route the lines properly.

 

[Trey Hardy]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

If I were you I would order a tru cool 40k transmission cooler to replace that one
They send you the brackets hoses and clamps for install

When I did mine it dropped my temps from 205 and higher down to 165-175’

Also I spliced the line that went into the radiator in a way it would run though the radiator along with the additional cooler. Well worth the cheap insurance

Also I mount mine up instead of down so I can bleed all the air and pre fill the cooler upon installation.
Hope this helps some!

 

[j91z28d1]

by short cut, he means you can't really flush the coolers very well, even the ones in the radiator end tank. so you should replace that before hooking it back up after a tranny rebuild.

but yeah, inline with the in radiator is a good idea overall. they didn't do the job 100%.

 

[swathdiver]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

Might as well have no cooler at all with it done that way!

It has to be radiator first, then the external cooler and back to the transmission. If you get that monster Tru-Cool, mount it low so it doesn't heat up the radiator and condenser.

My little factory external cooler works just fine.

 

[jeffm333]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

 

[ivin74]

Leave the oem cooler disconnected. The oem cooler rust over time and colant goes into the transmission and you will b left stranded on the side of the road.

I added the tru cooler to my suv and got the ecm tune to turn on the cooling fans at 190*. The factory setting turns on the fans is the 220ish degrees, that is way to hot. This summer I drove through the Arizona heat at over 100* and never over heated. Previous years always ran hot

 

[NickTransmissions]

Leave the oem cooler disconnected. The oem cooler rust over time and colant goes into the transmission and you will b left stranded on the side of the road.

I added the tru cooler to my suv and got the ecm tune to turn on the cooling fans at 190*. The factory setting turns on the fans is the 220ish degrees, that is way to hot. This summer I drove through the Arizona heat at over 100* and never over heated. Previous years always ran hot

You dont want to bypass the fluid cooler in the rad as the majority of heat exchange is done via that cooler. The large external trans cooler functions like an aux cooler giving an extra maybe 10-15 degrees reduction in terms of avg running temps.

I always advise customers to simply replace the radiator or have it and its int trans cooler reconditioned by a competent radiator shop to prevent rust-driven coolant leakage into the transmission if the mileage is high and radiator's never been replaced.

Adding a deep pan for xtra capacity also helps, esp for anything HD or HP.

 

[NickTransmissions]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

I imagine you can remove the factory trans cooler fittings and replace with AN fittings which are/should be threaded to receive your aux cooler's line fittings.

Summit has a page with a list of tpis - it may be worth a call to them if no one here knows. The threads in the radiator's trans cooler should be 6AN straight cut with an O-ring.

BTW - Im also in Vegas and if you're who I think you may be, we have chatted over the phone and both know someone named "Joe"...if im mistaken, please forgive me and disregard. If you have any trans specific questions feel free to post them in my 6L80 Info thread - link is in my sig...

 

[gooffeyguy]

If I were you I would order a tru cool 40k transmission cooler to replace that one
They send you the brackets hoses and clamps for install

When I did mine it dropped my temps from 205 and higher down to 165-175’

Also I spliced the line that went into the radiator in a way it would run though the radiator along with the additional cooler. Well worth the cheap insurance
View attachment 406945
View attachment 406946
Also I mount mine up instead of down so I can bleed all the air and pre fill the cooler upon installation.
Hope this helps some!

What's the benefit of bleeding air and pre-filling the cooler?

The fluid drains back to the pan when the engine is shut off. That is one reason why the level is checked while running and up to temp.

Cooler input/output orientation doesn't really matter. Mounted up just leaves fluid in the cooler when engine is shut off.

Air gets into lines every time engine shuts off, and gets pushed out as soon as engine starts and fluid fills the lines. Trans has a vent on top.

 

[BG1988]

Just had the transmission replaced in this truck and opted to have them install an additional transmission cooler. I believe it is a “supercool” branded cooler but looking at the receipt from the work it is not specified.

Upon first driving it, after a 25-30 minute drive the trans temp was at 203; hotter than expected especially with the additional cooler. I have not tested it uphill yet. Upon inspection, the shop simply disconnected the factory fluid lines leading to the factory “cooler” within the radiator, and connected them to hoses leading to the new (and surprisingly fairly small) external cooler mounted in front of the AC condensor. They didn’t cap the old radiator input/output lines either.

From reading about external additional coolers here and other places, I was expecting this to be put in series with the factory cooler, presumably in series on the “output” side of the radiator connection. Is this not the preferred/superior solution? Or is what the transmission shop has done normal?

I’m just learning about transmission replacements and transmission coolers, so any input and recommendations here are appreciated - including superior external cooler examples if anyones has them.

Many thanks!

203F is too high mine is at 140-145f after about 75min-90min of highway driving .. pull the transmission thermostat .(thermostat delete) Why enjoy 80-100k miles of use when it can last forever...300,000 miles or 500,000 miles, a million miles?

depending on how hot it is the MAX i have seen is 165F that was when it was 110f outside most likely if it was 110f I had the a/c on MAX

the transmission thermostat is just a scam to shorten the life span of the transmission....


Just a side note: lowering the operating temp isn't a substitute for maintenance i.e changing your transmission fluid

 

[strutaeng]

Yes, leave the radiator cooler connected. There are some vehicles that it's a common failure for the radiator cooler to fail (some earlier 4Runners and Tacoma's come to mind...)but not on these trucks. Of course, just about anything fail at some point. The thermodynamics are superior fluid-to-fluid than fluid-to-air.

My brother did have a transmission failure of his 90 C1500 due to radiator cooler sending coolant into the transmission. So he bypassed it.

 

[NickTransmissions]

203F is too high mine is at 140-145f after about 75min-90min of highway driving .. pull the transmission thermostat .(thermostat delete) Why enjoy 80-100k miles of use when it can last forever...300,000 miles or 500,000 miles, a million miles?

depending on how hot it is the MAX i have seen is 165F that was when it was 110f outside most likely if it was 110f I had the a/c on MAX

the transmission thermostat is just a scam to shorten the life span of the transmission....


Just a side note: lowering the operating temp isn't a substitute for maintenance i.e changing your transmission fluid

Trucks/SUVs 2014 model year and back didn't have the cooler bypass valve installed...The CBV didn't appear until 2015+

Trans temps should be consistently 175-180 and that assumes Dex 3 or 6 (at least IMO)...Dex 6 full syn gives you more of a safety margin owing to its more robust formulation but folks sometimes push it (temps in excess of 230 frequently) and that will shorten the life of any transmission.

 

[Doubeleive]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

you need 2 of each of these to make it nice and not a hack-job
upper 2 are on amazon, lower 2 are on ebay
these parts work with the factory lines and tru-cool and allows you use the oem cooler in the radiator + a tru-cool

 

[j91z28d1]

Trucks/SUVs 2014 model year and back didn't have the cooler bypass valve installed...The CBV didn't appear until 2015+

Trans temps should be consistently 175-180 and that assumes Dex 3 or 6 (at least IMO)...Dex 6 full syn gives you more of a safety margin owing to its more robust formulation but folks sometimes push it (temps in excess of 230 frequently) and that will shorten the life of any transmission.

I don't really know what he's going on about but he's got a hybrid and these are kinda weird. so what I've read the electric motors can create a lot of heat but there's no torque converter to build heat. so it seems they cooled the crap out of the fluid. there's 5/8in hard lines from the tranny to a front mount cooler, that about an inch thick. (and of course discontinued) it's the size the of the rad, half is tranny, half is hybrid inverter cooling.

they seem to have a temp stat of some kind at 167*. because that's the highest anyone ever sees. takes like 2h of stop and go traffic to get there. on my the daily loop, this one only sees about 140deg on a 100 plus deg day. I've seen it hit 167 when towing a car trailer, and very very long drives. but that's about it. they also have 3 speed cooling fans, where normal is 2. I don't know if the motors are more powerful, or if they just thought having a med speed saved fuel?

so again, these are just odd ball trucks. but they definitely run colder than what is considered normal for every tranny. in all the threads I've searched about these trucks, can't say I've found anyone say they have seen the 200deg that's normal for everything else. why that is? I don't know, but besides the tranny motors it's just clutch packs. seems they could have set the stat temp at anything they wanted. it has honestly made me me wonder if over cooling tranny fluid is a real world issue or just internet theory. gm definitely didn't care that these trucks can be driven around for their whole life and never see 180deg.

 

[NickTransmissions]

I don't really know what he's going on about but he's got a hybrid and these are kinda weird. so what I've read the electric motors can create a lot of heat but there's no torque converter to build heat. so it seems they cooled the crap out of the fluid. there's 5/8in hard lines from the tranny to a front mount cooler, that about an inch thick. (and of course discontinued) it's the size the of the rad, half is tranny, half is hybrid inverter cooling.

they seem to have a temp stat of some kind at 167*. because that's the highest anyone ever sees. takes like 2h of stop and go traffic to get there. on my the daily loop, this one only sees about 140deg on a 100 plus deg day. I've seen it hit 167 when towing a car trailer, and very very long drives. but that's about it. they also have 3 speed cooling fans, where normal is 2. I don't know if the motors are more powerful, or if they just thought having a med speed saved fuel?

so again, these are just odd ball trucks. but they definitely run colder than what is considered normal for every tranny. in all the threads I've searched about these trucks, can't say I've found anyone say they have seen the 200deg that's normal for everything else. why that is? I don't know, but besides the tranny motors it's just clutch packs. seems they could have set the stat temp at anything they wanted. it has honestly made me me wonder if over cooling tranny fluid is a real world issue or just internet theory. gm definitely didn't care that these trucks can be driven around for their whole life and never see 180deg.

Are you referring to the OP?

 

[j91z28d1]

Are you referring to the OP?

nah, the BG1988 guys you quoted.

 

[NickTransmissions]

nah, the BG1988 guys you quoted.

ok - I responded to his post as he quoted the OP, telling him to pull the trans thermostat...The OP has a '13 Z71 Burban conventional gasser w/a 6L80 so wanted to let him know (just as i recently learned on this forum) that the conventional GMT900s didn't come w/the CBVs...

That out of the way, I keep thinking about your offer to send me that 2ML70 Hybrid trans...Been wanting to do one but no yard or core supplier around here has seen one in ages, lol...Perhaps we can talk off line if you get to the point you're seriously thinking about sending one to me to overhaul.

 

[j91z28d1]

ok - I responded to his post as he quoted the OP, telling him to pull the trans thermostat...The OP has a '13 Z71 Burban conventional gasser w/a 6L80 so wanted to let him know (just as i recently learned on this forum) that the conventional GMT900s didn't come w/the CBVs...

That out of the way, I keep thinking about your offer to send me that 2ML70 Hybrid trans...Been wanting to do one but no yard or core supplier around here has seen one in ages, lol...Perhaps we can talk off line if you get to the point you're seriously thinking about sending one to me to overhaul.

I'll pm you in a few.

 

[swathdiver]

Working with the shop now to put them in series as everyone has outlined (and how I thought it would originally be done), and we have a snag: They have said (and showed me) that the inlet connector on the 2013 SUburban radiator isn't the same type fitting we got ind n the cooler kit or that I've seen referenced in videos and posts here. Mine looks like "quick-connect" with a snap ring? The typical connectors I've seen people using (LIke the Derale part D13004, https://www.etrailer.com/Accessories-and-Parts/Derale/D13004.html ) are threaded and different from what it appears I have here?

Is anyone familiar with the actual connector I'd need to purchase so I don't need to cut the metal fluid line?

That's an old style connector, GM hasn't used those in over a decade. I was trying to get Derale to make us a slightly larger cooler with the OE fittings but it fell on deaf ears.

So factory installation it is for me, works fine anyways.