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Snapped off a heater core tube :(

47K views 25 replies 16 participants last post by  candi@az 
#1 · (Edited)
So last night when i took the X out for the first time after the body lift, it started spewing steam everywhere. When i popped the hood, low and behold, after the body lift i had snapped one of the heater core tubes off. Right now it's holding on with about a 1/4" of tube left sticking out of the firewall. I called up nissan and they said that i have to replace the entire heater core because they do not sell the little plastic hose thing that screw right on. Now, Being a high school student with one hell of a mod bug, I don't want to spend $150 + shipping on a new heater core. I'm looking for the cheapest fix possible. I'm thinking about going down to a wrecking yard and seeing if they can rip the heater core out for me (or do it myself) and just buy the nozzle.

Unless anyone else has a better plan or knowledge of somewhere else i can get a heater core tube?


Edit: Can i just disconnect the inlet and outlet hoses and join them together temporarily so i dont have another spill? at least until i get a new core?
 
#3 ·
We F’d this same thing up on a buddies X during his BL. We did not take it off while lifting.
We just cut the broken tube so it was clean and would not crack more and attached the hose onto the ¼” that was left. It has been holding for more than a year. Do you have enough to grab and hold the hose?
 
#4 ·
Yea you can connect the tubes, you just won't have A/C. Thats what I did when mine broke. I went to Lowes and bought some copper connectors. I mixed and matched em and ended up with a piece that would fit in the broken tube and the inlet tube. The end that went into the firewall had threads that bit into the plastic some. I've had it in since september of last year and its been worked fine. I bought a used heater core from some one that was parting out a wrecked X... just haven't had the time to replace it
 
#6 ·
Maybe a mod here can go to the how to thread and bold and jack up the font about this.


Snow chaser, not much you can short of yanking it, the tube is not a separate part and the way to get to it means ripping your dash out. Mines been leaking slowly for months and i just live with it. I did put a better clamp on the hose and that helped the most.
 
#7 ·
i was thinking about getting a replacement off ebay (they run about $50) or taking a large threaded brass nipple and threading it into the tube. its a hame nissan doesnt sell the tubes separately.
 
#9 ·
We almost did the same thing to RATTFINK's rig when we did the BL. We ended up disconnecting the bracket that held the hoses from the firewall; that gave it enough flexibility to allow the lift.


**Always have someone watching under the hood for parts that look stressed when you are jacking the body up off the frame!


In the meantime, yes, you can simply connect the hoses to each other and refill the cooling system with coolant. You just won't have any heat in the cab.
 
#11 ·
Never did it on a BL, but its easy enough to see how.

Mine went on the engine swap, as one of my compadres helping out didn't know to just cut the rubber hose length-wise at the nipple, he tried to TWIST it off, and snapped off the nipple.

The part is not expensive actually, maybe $25 brand new.

The labor to get at its a PITA, as the damn thing is behind EVERYTHING, against the firewall.

The nipples are all one part with the rest of it.

If it snaps off with enough sticking out, as Tom mentioned, definitely jury rig a new hose over what's left and call it a day.

If there's not enough (Mine snapped of about flush...and nothing had enough grip to stay on...)...well, just take out the dash until it looks like this:



and then like this:




Take out the old one and stick the new one in the same spot, and put the dash back in, and you're good to go.

:wink-big:

I took my time, used tape and a sharpie to mark all the matching plugs and harnesses and brackets, so I could just reverse the process to put it all back.

It took a few hours (5?) on a Saturday to get it all out including the seats and console, etc..label every thing, and put the new core in.

It took maybe another 2 hrs on Sunday to put it back together again.

Its not hard, just tedious.

If I had a helper, it probably would have gone a lot faster.

You don't need any special tools, just normal screw drivers and sockets, etc...mostly smaller sized.

Most of the panels snap on/off...and the ones with screws have little covers to tip you off, or the heads are exposed.

Some stuff you can take off one side and pivot out of the way enough.

Some stuff its just easier to remove a part with a bunch of other parts attached to it to prevent having to mess with every dam screw, etc.

I used the sharpie and tape to mark match lines too, so I would see how a panel or bracket went w/o having to try to remember.

It looks worse than it is.

If you were planning on and dash related mods, or running wires through the firewall for lights, etc...this is an EXCELLENT time to do that while all the usual crap is out of the way.

:wink-big:
 
#16 ·
Glad this thread exists! I blew a hose today on the interstate, caught a ride to a parts store, got back and pulled off the hose and the core hose connector fell apart.

Was thinking a new core had to be purchased ... off to Lowe's to buy some brass fittings. Will post tomorrow good news if it works.

Thanks guys :biggrin:
 
#18 ·
Heater core inlet & outlet nipple repair

This just happened to my 16 yo son as he tried to monkey off the firewall heater hose with a wrench. I have since instructed him how to properly attempt to remove a suck hose-on-nipple via an axial slice ‘n peel method.
I am considering a “sleeve” repair if there is enough tube left to grab a hold of and clamp to. The basic solution is to create a copper* sleeve to fit internally or externally on the remaining broken nipple of the heater core. The idea is a tight fit tube over and/or inside of the broken length of tube. I may have to reduce or increase size of repair “sleeve” by sanding or machining it to size for a relatively tight fit, but leave enough for the gasket/sealant compound. If I am lucky you might find a nipple and create a sleeve on the heater core end of it about 1-1/2” long and still have a 1” or so left to secure hose with a clamp.
I will use some sort of automotive gasket maker to “seal” the sleeve as it is inserted around or into the prior broken nipple’s hole. Obviously I would need to clean all surfaces before attempting to “glue” the replacement sleeve/nipple in place.
Ideally, if there is a bit of external nipple left, and for overall strength, I might sleeve the outside of the broken nipple and slide in a new nipple of the OEM diameter nipple. I am thinking it best to sleeve it internally AND externally for strength; i.e. double sleeve.
Concerning an internal sleeve, I will have to be careful to not diminish overall heater tube diameter by so much to cause a flow restriction, which will increase pressure at the fitting repair – possibly causing failure. As well, in the South, it probably is not an issue to sleeve the broken nipple internally as we only need a fraction of the heat output. However in the Northern climates probably better to not internally sleeve as this will also reduce the exchange capacity rate (amount of coolant that flows through heater core per unit of time) and thereby not being as effective.
*aluminum (or heater core plastic nipple <not recommended as it might easily break off again) or similar material. Be careful as to match the material to your vehicle as some coolants are not all copper and aluminum friendly. The manufacturers recommended coolant should indicate which material is safe to use. (i.e. a disclaimer “Not Safe for Aluminum Engines”.)

Of course as jhutch mentions there is a “professional repair” part available from Doorman. But this I would guess means removing the dashboard…yeah, always an option if the sleeve fails.

http://www.dormanproducts.com/p-656...ater%20Core%20Tube&enginebase=V6 3.3L (3275cc)
 
#19 ·
replacing those tubes were a piece of cake -- I did not have to take dashboard out -- take out blower motor housing / air conditioning core and cabin air filter -- i'm 6ft and 200 pounds - took me hour to hour and a half and a little bend of the body with a flashlight -- don't be scared -
 
#20 · (Edited)
jhutch:

Thanks.
I looked at some threads on this. This seems straight-forward assuming fairly easy access to the tube mount screws. My only question is:

When you say ” take out blower motor housing / air conditioning core and cabin air filter”

Does this mean I would have to disconnect Freon lines from the engine compartment, which means I would have to evacuate and recharge the AC, or just disassemble ac box/cover which houses the filters from the evaporator?
 
#21 · (Edited)
Removing Cooling Unit & Fan Housing

replacing those tubes were a piece of cake -- I did not have to take dashboard out -- take out blower motor housing / air conditioning core and cabin air filter -- i'm 6ft and 200 pounds - took me hour to hour and a half and a little bend of the body with a flashlight -- don't be scared -
Jhutch:

This repair is for my Girlfriends Xterra that she is letting her daughter drive. I do not want anything else to break on my account. She is already going to be upset the repair is taking a long time (waited for parts, then a rain-day, then other obligations) and that it is due me letting my son touch the vehicle.

The AC was reportedly not functioning, so not too worried about having to deal with Freon lines; I was just curious. Nissan Tech sheets confirmed that the Freon needs to be captured and lines disconnected.

Normally I am pretty adept at figuring these things out, but none of the diagrams I found show the exact screw locations on the cooling unit case. All Nissan tech sheets*, and all other blogs or forums, simply say “remove the cooling unit”. I removed the glove box, then all the screws that I could locate under the dashboard on the blower motor housing and air conditioning evaporator core / cabin air filter case (i.e. “cooling unit”). Both housing and unit wiggle nicely as if disconnected from mounting locations. Only a minor interior piece from the center console will have to be navigated by about an inch. Yet there could be a screw holding the blower motor housing and the cooling unit together closer to firewall or just the AC lines.

On the engine side of the firewall there appears to be a rubbery drain tube for the evaporator just about 8" below the heater tube holes in the firewall. Do you recall if this rubbery drain piece pulls straight off? Or does it even need to be removed?

On the engine side of the firewall there is also an access/cover plate with two screws right below the heater hoses. Does this access/ cover plate need to be removed to access something inside evaporator case, like another screw?

Photo attached (sorry it is small).

I am just trying to be extra careful.

Any help is appreciated.


Techman_hou

Nissan Service Guide for Heating and Air Conditioning system:
*http://worldtracker.org/media/libra... 2000-2004 Approved/Nissan Xterra 2002/HA.pdf
 

Attachments

#23 ·
HFD1 Tuner:

Thank you. I more or less figured that is the case. I was hoping to be able to disassemble blower motor housing and then gain better access to the evaporator unit box to lower it out of the way and not disconnect the AC lines. However, there must be a screw on the blower motor housing venturi chamber on the inside corner of firewall and right of vehicle that is inaccessible.

I have some other projects going and the vehicle is not needed right now, at least not any urgent needs to have it operable. I have postponed doing any further disassembly as it is drivable right now with most of the HVAC blower and cooling unit behind glove box is disassembled.

Now I just need to find the time to check to see if Freon is in the AC lines, as last reported from my GF's daughter the AC did not work. Hopefully they are near empty, so I can finish the job myself. Otherwise I will have to drive it to a shop to have the Freon recovered. If that is the case, this repair might have been cheaper to have it done at a shop that has Freon recovery equipment. In either case this $25 for parts heater hose replacement job is now approaching $150-$200 or more, as I will now have to get a new AC drier, AC Flush kit, Freon (probably an R-134a adaptation kit as well) and O-ring kit once I break open the AC piping.

This really sucks because the tubes were replaced just a few years back, about 2010, when GF had an engine overhaul done just after we met. There is no way they should be that fragile. I recall her telling me one of the reasons it took over 5 months to get back (issue after issue with inexperienced mechanic)...
GF: "Oh, the mechanic now has to replace the heater core tubes."
Me: "You mean the heater hoses, right? He should put new ones on, I would insist, if it was my vehicle."
GF: "No, he said heater core, tubes I think."
Me: "Wow either way he will likely have to take dashboard apart to do so, seems odd to have to do that for an engine rebuild/swap."

When we finally got it back the guy said:
Mechanic "Oh, you will have to replace the heater and lower radiator hoses soon. We only chaned the small ones on the engine and didn't want add any more to the cost, nor to keep it much longer."

That was on at least a $4K, if not $5K engine swap/rebuild.

This should be easier than this. That is no need to disconnect AC lines to change out plastic tubes for Heater Core. Well, in the first place these dang heater core tubes should be less fragile. I can just hear the Engineers now...

Supervisor: "Hey! Thomasino, you designed the heater core with replaceable tubes?"

Thomasino: "Yes, they will likely break since the plastic we used to minimize the vehicle weight is more fragile than the metal ones on most heater cores."

Supervisor: “Ah so, I see.”

I guess the manufacturers have to do something to keep certified technicians earning money.

I am also still thinking about doing an internal sleeve on the replacement tubes to prevent this headache for the next time. Will seek out/manufacture a ~1/2" O.D. X 1 1/2" L thin wall (abt 0.022") Stainless Steel Tube Support Insert. I just need to calculate the amount of thermal expansion and minimize the tube insert O.D. to meet the expansion amount in order to not break plastic tubes once inserted. The amount is probably negligible (< 0.010"), but hey, I got an education in Mechanical Engineering, so I might as well use my knowledge somwhere.

Techman_hou
 
#25 ·
Follow up report...

I finally got around to putting the Heater Tubes in and somewhat fortunately for me the AC low pressure valve core was shot (strange since the AC was a paid-for repair by my GF a year or so ago with a repeat visit since it lost all the Freon in a month or so afterwards & again after the return for re-repair), so did not lose any Freon. We had a Haynes Repair Manual for the Frontier/Xterra/Pathfinder, but it was misplaced when I originally posted. Once I read over it I felt like a dummy. The manual also reads as if you have to disassemble the whole Dashboard, but really you do not.

The disassembly is really pretty straight forward. My mistake was interpreting that the Blower Fan Intake Plenum/Box also had to be removed, it does not, however the Blower Fan Motor does need to be removed (3 screws, bypass tube/“vent hose” and electric connector) and it helps to take out a few screws on the left side of the Blower Plenum assembly (especially the one way up in the cylindrical “hole
“).

The other primary interference inside the cabin with removing the Evaporator Box is the small “T” shaped bracket on the Center Bracing of the Center Console Tower located at the lower-left at the bottom of the Glove-box. To access the mounting bolts for the “T” most of the Center console needs to be removed; specifically the Shift Cover (no screws, it pops off), and Bezel for AC and Radio. One all the screws are out the underlying secondary interior panels, these can easily be pushed aside far enough to access the 2 screws that hold in the “T” bracket. Then all that is left is disconnecting the AC Thermo Amplifier –sensor (electrical connector on left front of Condenser Cooling Box) and the Freon Lines at the Firewall in Engine Compartment (& definitely check the Freon charge level of the AC before removing Freon lines).

So far I see no leaks after a week or so of driving.

For the AC I changed out all the easily accessible O-rings in the Freon lines (all but those to condenser – I gambled that the amount of work to remove the radiator to access them was too much effort if the system held a vacuum) and dropped in a new Accumulator/Filter/Dryer, drew a solid, near 29mmHg, (vacuum on the AC system, and then loaded two 12 oz. cans of R134a. AC seems to be just fine with the two cans, so will leave it at that to see if it holds (it should because vacuum held overnight).
 
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