This happened this week: a friend was driving the 2008 Pathfinder and the infamous heater pipe broke at the plastic fitting. So, we got the vehicle to my house and I gave her my 2006 Pathfinder to use. Guess what happened? A few days later, the same thing happened with the heater pipe on the 2006! I got the new heater pipe for $250 (Quirkparts via Amazon.com) and put it in on Friday. I was a little concerned about getting the end of the pipe that was broken inside the hose out, but it literally crumbled into pieces when I squeezed the hose (fortunately I was able to push the hose down before it fell into the cooling system). I was going to do a "how to" on it, but there are already a few good "how to" vids on YouTube such as this:

https://www.youtube.com/watch?v=0khBgAVWRzg

A couple of key points and tips: You need to remove the passenger-front wheel and the plastic wheel well liner; once you do, the bottom end of the pipe assembly is right there! You don't need to remove the upper intake plenum nor the cover over it; it's a tight squeeze to get out, but a little patience and pulling up on the harness on the firewall and it will slip out and in (I actually took my cordless sawzall and cut the pipe into three pieces for easier removal). I have a carburetor adjustment tool with a 1/4" drive end and a 45-degree bend at the end; combined with a 10mm socket, it made getting the two nuts off of the firewall a piece of cake! Perhaps the worst part of the job was getting to the spring clamps on the hoses at the heater core outlets and removing the hoses from it! As suggested in the video, lube the inside ends of the hoses with liquid dish detergent and they'll slide on the pipes with a slight push. I ended up needing two gallons of coolant, exactly, and I did drain the radiator first. $250 shipped and with taxes is the cheapest I could find the pipe for, which I found on Amazon and also NissanPartsDeal.com and a couple other places. Part of the reason why it's so costly is that it comes with a new heater pump, along with hoses and spring clamps. If you have a V6-powered, R51 Pathfinder with rear heat, the Nissan part # is 92408-ZL90B.

Both Pathfinders have over 200,000 miles on them (254,000 and 210,000, respectively) and are over 10-years old (12-years and 14-years, respectively). With that in mind and considering how brittle the plastic was, my recommendation to all is that if your Pathfinder is 10+ years old and has high mileage, you should really consider replacing this part as "preventative maintenance" rather than take a chance on it breaking on you when you're on the road. My 2006 broke in Virginia Beach, which is over 3-hours from my house and a $1000 tow bill! Fortunately, my friend had towing insurance which cut it down to $540...but still! So, don't say I didn't warn you!

Good point!!
Should we make this a sticky?

Looks like 2-3 hours? It occurs to me this may be where the green along my rear heater core lines could be coming from.

But, let's say it's not...from the video, this looks like a potential opportunity to cut and replace, or repair some of that tubing at the same time? Looks like they move pretty freely once the hoses between them and this assembly are gone.

Coincidentally, when I was doing my oil change the other day. I was looking at the plastic pieces part of the heater pipe assembly also. I didn't even want to touch it in fear of breaking or cracking them. Looks simple enough of a job though, although seems pretty pricey for what it is. Then again, I just spent $200 on nuts and bolts for my rear suspension makeover...so I guess it isn't too bad of a price in comparison.

Well, if they sold it without the heater pump, they could've knocked at least $100 off the price of the pipe assembly, easy! It is what it is, though.

I took a look at mine and it seems fine. I mean, as much as a visual check on a plastic part subjected to years of heat can tell me

Unfortunately, it's really clean throughout, which means I eventually may still have to deal with a rear heater line leak. Someday...

You really can't see the part where it breaks until it does. It breaks at the inlet inside the hose that goes down to the engine. The plastic just crumbled apart when I pinched it.

You are really trying to ruin the Fourth of July long weekend for everyone, aren't you

It's my project for the weekend, so I just wanted to share in the fun!

So I was actually looking for something completely different tonight, but, uh...I found the part number for the assembly without the motor and whatnot. Runs about $120. It's 92412-EA500, look up code 27185M. I ran it in NissanPartsDeal and it goes to the same drawing as the larger assembly.

https://www.nissanpartsdeal.com/parts/n ... AUTO;6=LE)

I'm really thinking about the aluminum lines running to the rear heater core. If I drain and fill for this, I'm going to knock it all out. At least JB Weld around whatever might be leaking or something. Won't be any time soon though, as we're not allowed to travel very far anyway, and the base auto hobby shop isn't open yet. Definitely want the scissor lift for the PITA this will probably become.

With 210K and 260K miles on my Pathfinders, I'm probably better off in the long run getting the whole assembly and not have to worry about the heater pump and the rest of the hoses that come with it. FYI, once you get the clamps off of the hoses and are ready to start removing them from the pipes, spray them with carb cleaner and wait 30 seconds. It will soften the hoses and make it easier to break them loose. I just got done putting my second pipe assembly in last night, so the two should be good for a little while! One thing I noticed is that the heater pump on the 2006 was a Bosch unit and a lot larger than what was on the 2008 and the replacement part. The factory pump on the 2008 had a brand name on it, but I couldn't make out what it said.

I did some more poking around. Looks like the Nissan sites list that pump as no longer produced by Nissan. On eBay, I found a thing that claims to be compatible with that part number and some others:

https://www.ebay.com/itm/BRAND-NEW-Auxi ... 2386654591

So yeah, maybe better to get the whole thing. But if someone was just looking for those pipes, there they are...

Rockauto has them starting at $61, Gates is $112. You can find them under "water pump."

I was just looking at my heater pipes and the VK56 looks easier to replace. My heater pipes doesn't run along the rear firewall like the VQ40.

Yes, the V8 heater pipe is a different part than the V6.