Help Finding a Broken Fitting

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
Broken Heater Core Fitting

I smelled coolant this morning when I got out of my car. I looked under it and saw water dripping. I popped the hood and saw wet by the upper heater core fitting (I think) where it goes through the firewall. I touched the small hose and it started spraying coolant everywhere. The small tube has broken off. I'm having trouble finding the fitting on parts.vw.com so I can get the OEM part number. Can someone please help me find the part number?


 
Last edited:

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
The illustrations on parts.vw.com and vwpartswarehouse.com are not very clear. I think I need 5K0122157K. If I Google that part number the images look like it, but I'm not positive.
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT

The illustration is not a good representation of the part, that is what my trouble was.
I went to the dealer today. That is the correct part number. They want $70 something at the parts desk, not in stock, have to order it, be there in two days. The dude said f I order it from their website (which links to parts.vw.com, I had already looked it up) it's only $50 something and I can pick it up there, same delivery date!
They kill me! :(
I believe I saw it on ECS Tuning, and Rock Auto, for even less. I'll check later when I get home.
I guess I have my weekend project. :mad:
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
5K0122157K HVAC Heater Hose (Front) is the correct part. I ended up ordering it through the dealers website and picking it up there. It was $45.02 after tax and I didn't pay any shipping.



Now the fun part, replacing it...
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
How did that small tube break?

It is snapped off right at the base. I will replace it this weekend and look at it more closely to see if I can determine why it broke.
It is a pretty small diameter tube so I don't imagine it would take much to weaken it if it was pushed on. It is a molded plastic fitting. If they didn't design it with some decent radius' in the corners cracks could develop over time just from the flexing of the little hose as the engine moves and puts tension on it. On the new one the corner radius are pretty small. It's also in the back not too far from the DPF. It could be getting baked during regen and has become brittle.

I have never poked around back there so I'm pretty sure it's not been damaged by me. When the dealer did the stage two fix, did they stress it? I don't know.
 

adjat84th

Veteran Member
Joined
Dec 13, 2008
Location
Virginia Beach, VA
TDI
'01 Jetta TDI/'15 Golf TDI
The small hose is attached to a hard pipe running on top of the turbo. The reason it's U-shaped is to absorb the motion of the engine rocking back and forth. I've always questioned that little hose barb and it's likely inevitable failure. How many miles on your car?
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
5K0122157K Hose Replacement

Between other activities commanded by The Events Coordinator, and then having to go on a business trip, I finally got the time to fix my car this weekend. Here is how it went:

I figured I would finish draining the coolant system first, even though with the busted fitting it had pretty much leaked out.

To gain access to the heater hose..

Remove this breather hose.


Unplug the sensor under the breather hose. Secure it safely out of the way.


Disconnect the sensor and vacuum line to the air intake duct. Secure them safely out of the way. Undo the clamp and remove the air filter cover/front section of duct.


Disconnect these two vacuum lines from rear section of the air intake duct.


Here...


...and here, on the right side of the tee. Secure them safely out of the way.


Loosen the clamp and remove the rear section of the air intake duct.


Remove the screw holding the intake elbow, and give it a quarter turn clockwise to remove it.


Now you have a clear shot at the clamp on the small hose. Remove it. use a screw driver to pop up the clip retaining the heater hose fitting. Disconnect the hose from the firewall.


This connector and the metal water line assembly are in the way of access to the clamp on the large hose. Disconnect the sensor and pop the red part off of the bracket. Remove the screw securing this end of the metal water line assembly.



To be continued...
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
5K0122157K Hose Replacement - Continued

Sorry, I didn't get a pic for this next step. :(
To remove the metal water line, there is an aluminum duct that first must be removed to gain access to second of the screws that secure the metal water line assembly. Remove the aluminum duct. Remove the second screw. Secure the metal water line safely out of the way.

This is the clamp for the large hose, nicely tucked away between the back of the motor and the firewall. Not a lot of room to get a pair of pliers in there to get it loose. I had to send myself to timeout for a few because of my language. Remove this clamp and the heater hose is free!


Reverse the steps to install the new heater hose.



I'm slow, on purpose. Even with my timeout and grabbing a sandwich for lunch, I did the job in a few hours.


The replacement hose looks exactly the same construction as the original. The original one had snapped off and I'm not thrilled about how thin the wall is on the small tube. I hope this is a fluke and I'm not doing it again at 240K miles.
 

adjat84th

Veteran Member
Joined
Dec 13, 2008
Location
Virginia Beach, VA
TDI
'01 Jetta TDI/'15 Golf TDI
If it makes you feel any better, I had to customize the hose coming off of that barb for use with a different turbo. It was putting some stress on that barb more than the stock hose does, so maybe a fluke. This is the first thread on this exact piece I recall seeing.

Also, nice writeup!
 

PLC Geek

Active member
Joined
Jan 24, 2017
Location
Murrieta, CA
TDI
2015 TDI SE 6MT
PLC Geek, did you have your DPF replaced under warranty? If so, how recently compared to this failure?

Yep, over a year ago. Then it went back a few weeks later because of a DEF leak on the top back left of the motor.


My heater core was going bad too. After I replaced this fitting my wife informed me that she had cold air blowing from her side. :( To remove the heater core I was back into removing this fitting to get access to the 6mm bolt that secure the heater tubes to the firewall. I'm getting proficient at this task now, I had the fitting disconnected in less than 10 minutes. :D
 

tncrom

Well-known member
Joined
Sep 30, 2013
Location
Iowa, East Central
TDI
2013 Passat TDI, Manual (Took Buyback), 2015 TDI Passat SE Manual
A note of thanks for the write up, PLC Geek! I just removed my hose after reviewing, studying, and following your directions and images. Thanks very much. My story is similar to others in that the nipple broke off. Of course it decided to go on me while traveling with family two weekends ago; 102F, Kansas interstate between Ft Riley and Topeka. I don't why it didn't overheat, but I was able to make it to Topeka. I'm very disappointed in VW's design of this fitting. It's clearly a weak point and a defective design. Was fortunate that my daughter who lives in KC was available to drive us back to Iowa. Went back down to Topeka with a u-haul trailer and brought her home to Iowa to do the work myself. It's been a hassle, but this group has made it much better! Boo VW.
 
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