What is this line that leaks?

[TahoeLT10]

After some prolonged absence and a quite few repairs, I need some help again. After some extreme cold in Colorado, I had to replace the throttle body sensor as truck went into limp mode. All went well, but when deep under the hood I realized I have a small coolant leak from a line pictured. What is it? Is it the tranny coolant line? Can I replace just the fitting or the entire line needs to go as its a whole piece with the fitting attached? Thank much@

 

[ivin74]

That is a common leak spot for these suv's, those coolant lines go to your heater and not the transmission. Replace with oem fittings DONOT use dorman or aftermarket junk. Those are the coolant tee's

They sell aftermarket aluminium tee,s but are like 90 bucks each. Several members have use them. For the price of those aluminum tee's you can replace twice. If oem lasted this long stay w oem, chances are you will probably won't own the vehicle by the time they need to be replaced again.

 

[Tonyrodz]

That is a common leak spot for these suv's, those coolant lines go to your heater and not the transmission. Replace with oem fittings DONOT use dorman or aftermarket junk. Those are the coolant tee's

They sell aftermarket aluminium tee,s but are like 90 bucks each. Several members have use them. For the price of those aluminum tee's you can replace twice. If oem lasted this long stay w oem, chances are you will probably won't own the vehicle by the time they need to be replaced again.

I just wanted to add they're very easy to replace, just a little bit of a pita if you have big hands.

 

[Joseph Garcia]

If one tee connector is leaking, the other tee may do the same in the not to distant future. Replace both tees. I found these tees and fittings to be a b-i-t-c-h to replace, due to limited space for big hands (as @Tonyrodz stated above), when I needed to replace mine. Be sure to wear gloves, as the firewall insulation around the tees will get under your skin and itch like h-e-l-l for a few days.

I strongly recommend that you replace all of your rubber coolant hoses as well, while you are at it. My problems started when one of the heater hoses tore itself apart at one of the tees.

 

[Tonyrodz]

Here's both tees with part numbers.

 

[donjetman]

TahoeLT10,
In theory the heater Ts are easy the change. In reality I found them the be a giant PIA. I replaced both with GruvenParts $billet$ aluminum Ts.

At the same time I replaced the water pump, thermostat, coolant (NAPA Orange), and upper and lower radiator hoses. I replace the heater hoses too. One of the heater hoses has a Y in it. I replaced it with Dorman# 626-553 = NAPA# 827-5730-1. either of these have a metal Y, not a plastic.

 

[Geotrash]

TahoeLT10,
In theory the heater Ts are easy the change. In reality I found them the be a giant PIA. I replaced both with GruvenParts $billet$ aluminum Ts.

At the same time I replaced the water pump, thermostat, coolant (NAPA Orange), and upper and lower radiator hoses. I replace the heater hoses too. One of the heater hoses has a Y in it. I replaced it with Dorman# 626-553 = NAPA# 827-5730-1. either of these have a metal Y, not a plastic. View attachment 364282
View attachment 364283

I had the Gruven aluminum tees in my 2012 and just replaced them with OEM tees because I couldn’t get them to stop leaking. There is no barb on the heater core pipes so I had to get in there with a short screwdriver every season change and got tired of it. You could use spring clamps on them I suppose but o ended up destroying the silicone hose getting them off the tees. OEM will last as long as the truck at this point, and no more leaks.

I also have the Gruven tees on my 2007 and they aren’t leaking currently but the next time they do, I’m pulling them out. I tightened them in the fall for the third time, so maybe third times a charm.

 

[TahoeLT10]

What a community! Thanks much for this very detailed info.

 

[gooffeyguy]

Worm drive hose clamps shouldn't be used (or even sold) with silicon hose. The silicon is too soft and squeezes through the slots and also gets torn up by the gear. At the very least, use ones that have a smooth metal lining, like these....

 

[Jimmyy]

I just wanted to add they're very easy to replace, just a little bit of a pita if you have big hands.

You know what they say about guys with big hands.




They wear big gloves.

 

[petethepug]

use ones that have a smooth metal lining, like these....

 

[donjetman]

2+ yrs and 21k miles, no leaks and I haven't retightened them

 

[davidavidd]

My two cents, don't ask me why, use OEM tees and a pillow for your ribs

 

[donjetman]

3 yrs and 30k miles and all is well still. Haven't had to touch them.

 

[OR VietVet]

If using the tees, use GM tees.

Wherever possible, I have used band clamps for years.

 

[LaxCoachT]

Question on the Gruven tees...

With the hard pipes going to the rear heater, did you butt the blue hose to the raised lip or force it over the lip?
I'm having a helluva time trying to get the hose over the lip...the damn trans dipstick couldn't be more in the way.

thanks!

 

[davidavidd]

I saw the post and I remembered how much my stomach and neck hurt changing those sh## pieces. Follow the advice, change both at once.