99 Suburban Rear Heater hose tee leaking

[drshock]

I had an issue with the original nylon rear heater hose tee cracked and leaking on my 1999 Chevrolet Suburban diesel. I found a related thread in the forum about this here - http://www.thetruckstop.us/forum/showthread.php?26743-1999-Sub-rear-heat-tees-part-number-anyone

But the GM hose/tee assembly mentioned there, 15979269, has now been discontinued. The tee is a proprietary design, 3/4 x 3/4 x 5/8. Not something you can pick up over the counter anywhere and I really don't like making modifications from the factory design. So I wanted to share here that fortunately I recognized this EXACT same hose tee is used on the 1992-1996 Chevrolet Impala! It is 100% identical with the same casting marks and design as original (I am the original owner of this Suburban). Contrary to some Google hits out there, no flow restrictor is used in the tee for the 1996-1999 design. So you just need the tee.

GM part 12522867 is what you need. I don't understand why GM missed this and did not list this tee number as still available under the Suburbarn parts list but here it is - http://www.rmsautoparts.com/proddetail.php?prod=12522867

Hope this helps someone else.

 

[Burning oil]

Welcome, Nice first post. Stickies maybe?
GM is good about using parts from one vehicle to another. I run into it alot espescialy with electrical connectors.

 

[3500GMC]

Good catch on the substitute part! A little 'leg-work' can be a good thing.

TTS is becoming an authority on these trucks.

One of our Mods might wanna add this to the tech section.

 

[jrsavoie]

I have used a soldered 3/4" copper T with appropriate sized hose barbs. I used Pex tubing barbs at least one direction. I think the soldered T's are the way to go. I trust them way more than the plastic T's

If you want a restriction, just add a ball of solder

 

[JayTheCPA]

Wish I had found this a few days ago as the Burb might have a new 'T' versus the one out of the mechanic's truck when the dealership took pity on me as they knew that I was 600 miles from home.

X2 on making this either a sticky or part of the tech section as searching for "T connector" gets far too many hits that are not much help.

As far as substitutes / alternatives to the OEM T, I did get a comment that there are brass connectors out there but will also need to mod one of the hoses so they are all the same size.

 

[JMJNet]

As far as substitutes / alternatives to the OEM T, I did get a comment that there are brass connectors out there but will also need to mod one of the hoses so they are all the same size.

The mod is necessary anyway and TurbineDoc (Tim) actually showed this in the other forum or here, I forgot.

You need to get a 1/2" NPT to 3/4" Barb connector to replace the coolant crossover quick connect (which is also prone to leaking).
There is a GM ACDelco part no if you want one from GM but it is nothing special when I got it except it cost $10 as supposed to may be $5 from chain part store.

Then use 3/4" Tee in the heater hose split point.

Get 2 feet of 3/4" heater hose to connect/replace the one from coolant crossover to the tee.
You can also get 1" wire loom to protect that newly installed hose.

This will probably outlast the truck.

 

[juddspaintballs]

Sorry to resurrect this thread, but the coolant crossover quick disconnect - I'm not familiar with it. Does anyone have a picture?

One of my T's started leaking tonight and I want to replace them both with brass or copper, but if there's something else I need to replace at the same time, I will.

 

[JMJNet]

The coolant quick connect is in the front right behind the t-valve downstream from the t-stats.

 

[juddspaintballs]

I replaced the quick disconnect too. Wound up buying a short piece of 5x8" heater hose and a few feet of 3/4" heater hose. I used 1"x1"x1" PEX connector for the T's since they fit nicely inside of the 3/4" heater hose. I then used 3/4" to 1" PEX connectors to reduce the hose from 3/4" to 5/8" for the quick disconnect and at the radiator.

 

[JMJNet]

I replaced the quick disconnect too. Wound up buying a short piece of 5x8" heater hose and a few feet of 3/4" heater hose. I used 1"x1"x1" PEX connector for the T's since they fit nicely inside of the 3/4" heater hose. I then used 3/4" to 1" PEX connectors to reduce the hose from 3/4" to 5/8" for the quick disconnect and at the radiator.

Great info. I know PEX barb is smaller so the 1" actually fit 3/4" hose and 3/4" actually fit 5/8" hose.

I will change the plastic connector to the brass soon.

That brass connector will outlast the plastic/abs connector.

 

[juddspaintballs]

If you use those Tees, they are "shorter" than the factory plastic Tees. The lower hoses probably won't have enough slack to connect without being stretched tight, but if you're replacing the quick disconnect anyways you're replacing that hose already. With enough KY and elbow grease, you can make 5/8" slip onto a 1" Pex connector, but it's gonna be tight.

 

[toddlnrd]

Hey guys,
My aluminum tube going into the quick connect piece has disintegrated. I purchased a replacement piece that screws into the thermo housing (no quick connection any more).

I was wondering if I needed any kind of flow restrictor. I baby the old girl (340,000 miles) and would hate to cause any unnecessary ware on her.

Thanks,
Todd

 

[Will L.]

No restriction needed afaik.

 

[handcannon]

I changed out the fitting in my pickup a couple years ago, no restricter. No known problems with going without the restricter.

Don

 

[toddlnrd]

Ok, great.

Thanks

 

[Husker6.5]

I had an issue with the original nylon rear heater hose tee cracked and leaking on my 1999 Chevrolet Suburban diesel. I found a related thread in the forum about this here - http://www.thetruckstop.us/forum/showthread.php?26743-1999-Sub-rear-heat-tees-part-number-anyone

But the GM hose/tee assembly mentioned there, 15979269, has now been discontinued. The tee is a proprietary design, 3/4 x 3/4 x 5/8. Not something you can pick up over the counter anywhere and I really don't like making modifications from the factory design. So I wanted to share here that fortunately I recognized this EXACT same hose tee is used on the 1992-1996 Chevrolet Impala! It is 100% identical with the same casting marks and design as original (I am the original owner of this Suburban). Contrary to some Google hits out there, no flow restrictor is used in the tee for the 1996-1999 design. So you just need the tee.

GM part 12522867 is what you need. I don't understand why GM missed this and did not list this tee number as still available under the Suburbarn parts list but here it is - http://www.rmsautoparts.com/proddetail.php?prod=12522867

Hope this helps someone else.

I really hate to burst your bubble, but the Suburban tee DOES have a restrictor in it and for a good reason, to regulate the balance of the flow between the two (front and rear) heater cores so that the front core doesn't take a full shot from the thermostat housing andvery little takes the "tee" to the rear hose. The return tee; however, has no restrictor in it. I know this because the hot water send tee on my '98 Burb (with rear heat/AC) failed on me three February's ago (it began leaking from a body crack where it steps down for the rear hosen- it is a design flaw and thr nylon gets brittle with age). At that time the tee assy was still available with the hose for the front heater attached to it from the Dealer for over $30, which was highway robbery IMHO. A check of all the major parts houses don't carry it, so I decided to fabricate my own out of brass for far less.

I have made a few of them for friends of mine with gasser dual heat Suburbans and can fabricate one up with the hose for the front heater attached no problem for a reasonable price plus shipping. Guaranteed not to break or leak and the restrictor will assure proper heater temperature balance front to rear. I can also make the tee for the return lines without the restrictor with the hoses attached.

 

[JMJNet]

I really hate to burst your bubble, but the Suburban tee DOES have a restrictor in it and for a good reason, to regulate the balance of the flow between the two (front and rear) heater cores so that the front core doesn't take a full shot from the thermostat housing andvery little takes the "tee" to the rear hose. The return tee; however, has no restrictor in it.

Would you happen to remember the size of that Suburban tee restrictor for the front and rear heater?

 

[Husker6.5]

Would you happen to remember the size of that Suburban tee restrictor for the front and rear heater?

IIRC, when I fabricated my supply tee from a brass PEX tee and a 1/2" copper pipe cap that I peened the open end slightly so I had an interference fit inside the tee leg to the front heater core before sweat soldering it inside the tee, I measured the diameter of the restrictor hole at just fractionally under 3/16". After soldering the pipe cap inside the tee, I drilled a 3/16" hole through the pipe cap.

I get plenty of heat from the front heater in the winter in sub-zero temps, and rear passengers have never complained about a lack of heat from the rear heater since I made my own metal tee for under $5, nor have I had a hose/tee failure/leak in the years since then.

 

[THEFERMANATOR]

I believe I put a 3/16" hole in mine when I built mine up as well. Could have used a slightly larger hole for mine as I don't get alot of rear heat at idle, but going down the road it is fine. Then again, the LB7 DURAMAX uses a lower flow water pump, and only a 5/8" heater feed line for the heater core. So the 6.5L fows more coolant through it's system.

 

[JMJNet]

IIRC, when I fabricated my supply tee from a brass PEX tee and a 1/2" copper pipe cap that I peened the open end slightly so I had an interference fit inside the tee leg to the front heater core before sweat soldering it inside the tee, I measured the diameter of the restrictor hole at just fractionally under 3/16". After soldering the pipe cap inside the tee, I drilled a 3/16" hole through the pipe cap.

I get plenty of heat from the front heater in the winter in sub-zero temps, and rear passengers have never complained about a lack of heat from the rear heater since I made my own metal tee for under $5, nor have I had a hose/tee failure/leak in the years since then.

I am doing the exact same thing but I have not drill it yet.
The cap is inside the 1" pex tee already.

So, my next step is to drill the 3/16" hole.

Thanks to all.