Heater replacement: HOWTO

[predator]

Heater Unit removal

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Follow this guide: http://www.skylinesaustralia.com/forums/sh...ead.php?t=31550 to remove your entire dash structure, leaving with what should look like this:

http://www.skylinesaustralia.com/forums/at...achmentid=10054

Now, to remove the actual heater unit, mainly to replace if leaking. Aircon removal and fan removal would be similar process.

1. Remove bolts/screws as shown in first pic, and 2nd pic

2. Also stick your head under and remove nuts holding plastic unit to the firewall, in passenger footwell, and up near the steering wheel (3rd pic)

3. Remove bolts holding stereo/climate control button brackets to main support bar as shown in 1st pic

[predator]

Support Strut

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Unfortunately, you're going to have to undo this to get the heater box out. I was hoping it wasn't required, but without moving it forward its basically impossible to get the box out.

1. Remove plastic climate control ducts sitting along top, and place aside.

2. Undo bolts on left side (4th pic), you may need a long socket 14mm to do this.

3. Remove one up near steering wheel bracing bar to firewall (3nd pic).

4. Remove bolts holding support bar to right a-pillar (2st pic). Should be 4x of these.

You will need the socket extender to get to these because of other things in the way. One down the bottom is the most tricky, and hard to see as its tucked near all the fuses

5. Undo two large bolts holding steering column to support bar, and drop steering wheel as far as possible

6. Pull bar slowly forward starting from left. May need to wiggle it a bit. Get on right side and pull forward on that side to move forward as well.

7. Pull support strut as far forward as you can, without breaking any wiring! (see 1st pic)

[predator]

Heater Unit and core removal

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1. Pop bonnet and remove coolant hoses to heater (see how to bypass heater core guide here: http://www.skylinesaustralia.com/forums/sh...ead.php?t=31403 for pics)

2. Disconnect plugs to climate control relays (circled green in this photo: http://www.skylinesaustralia.com/forums/at...achmentid=10464). Should be 3 of them.

3. Slide back bottom plastic duct that goes to rear seats from the bottom front of the heater unit

4. Gradually wriggle out the entire heater box. This isn't too easy, and it doesn't seem like it will come out.. but it will if all nuts and bolts are correct disconneted. You'll have to angle it to pop the core inlet/outlet from the firewall first, then start lifting it out at an angle.

As long as the support bar is far enough back, you should be able to lift the entire thing out. You may have to pull the aircon box to the left a bit also.

5. Stare at wonder at what has been causing you so much trouble (2nd photo), and see how it all works at the same time The heater core is the small radiator type thing at the back. It can be removed from the box by removing the screw shown.

6. To replace, visit your local wrecker, or track down a new one. If a wrecker, they'll probably make you buy the entire box to get the core - but as the cores CAN be different widths and the surrounding box CAN be a different shape. You're probably looking at $100-$200 for the entire box (+core) 2nd hand. Its up to you whether you want to take the risk of a 2nd hand, or find a new one somewhere.

Final Words

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Once the box is out, you *can* believe it or not drive around fine like that, as long as you bolt the support strut, etc back into place (1st pic) AND plumb up the coolant hoses. Whack back on the steering wheel, and you can drive around.

Its so cool, feels like a go-kart! But seeing as you'll have no vital items like a petrol guage, temperature guage, or speedo - best not too do anything to zany

[predator]

server problem so can't upload pics.. fuggin crapper..

tomorrow or something I'll upload the ones to go with the last post..

[ferni]

Big thanks to predator for this guide, saved me hours !

I got a replacement from my local natrad dealer ( www.natrad.com.au ) for 225, it was the 300zx heater core - I had to take mine out, show him it, then he measured it up and figured out it was the 300zx one, he ordered that for me friday morning, i got it Monday arvo...

took me about 2 hours to get the dash out, about another hour to get the heater core box out...

took me about 3 hours to get it back together (was being very anal about making sure every screw and nut went in the right place and was tight) so thats why it took a bit longer..

thanks again Gordon

[predator]

ferni: good to see it helped... and most of it is applicable to the GTR also.. Not sure what happened to those photos there

thats a good price though - unfortunately for me though, natrad no longer really exists in QLD :Oops:

yeah, want to make sure you get every screw back in the right place, or you'll be regretting the rattles and squeaks for a long time

[Phat6]

damn piccis aren't working ... I take it this is the heater radiator (and they split occasionally ?? )

[Phat6]

So what causes this exactly ? Should I be concerned that anything else is stuffed ... eg MY HEAD ????

[cul202]

If the pics are still around, can you re-attach them Pred? Will be looking to do this soon now the weather is cooling off. Cheers

[predator]

what causes it? I think the main cause is that if you have not turned on your heater for a while, the coolant sits in there in the radiator element, or if you've had just water in your radiator for any period of time (japs like doing this) - it will just gradually start to rust through. Under pressure, even a little tiny leak will cause a large amount of coolant to leak out. I could never see visually the hole in the core.

Just like your aircon, its a good idea to run your heating system once a week just to stop it stagnating.

Photos I'll try and find on my hdd.. but will be a bit of work to reattach them all

[Phat6]

thanks man ... I'll have some pics of my exploratry surgery up soon ...

[jezzerrr]

Is there some way just to flush it? mine isn't leaking (that i know of), would it be worth it just to attempt to flush through, even just to make sure I'm not turning a small job into a huge job? if you could still get a small amount of liquid through, you could put weak hydrochloric through it (or radiator flush or something) to break down the rust. anyone cut the old one up to see just how clogged up it was?

[ferni]

you could pull the pipes off outside the firewall (in the engine bay), and flush stuff through it there ig uess - those 2 pipes connect direclty to the heater core.

Also i have a copy of Preds photos hosted here: http://gtr.ferni.net/misc/dash_removal/

[jezzerrr]

cool, thanks for that

[coastlife]

Hi Guys just did mine .didnt do all this though. just took out the glovebox and air con part. unscrewed the plastic hoses from the core (4 screws in each) slid the core out the side. slid the new one in , put some silicone gasket round the silicon o rings and screwed the plasic hoses back on. DASH not touched.

[Jordan]

Sorry to dredge, but I am going to do this myself and my Natrad reseller cant even find the 300zx core for me. Does anyone know the part number I can quote them?

[ricsvtr]

Hey guys Ive just removed my heater core using the method which Skybee and Coastlife have described. You can actually remove the heater core without removing the whole dash although you will need to degas your A/C ( mine needed a regas anyway). All I did was -

Got the A/C degassed ($30 at auto sparky)

Undid the nuts on the A/C pipes going into the firewall

Remove glovebox

Remove evaporator unit, there is four screws to undo and three electrical connections that unplug and then the evaporator simply slides out.

Unscrewed the plastic pipes connected to the heater core. There are 8 screws in total (4 on each pipe) and some of the screws can be a little tricky to access.

There is a little plastic clip that secures the heater in place which needs to be unclipped, unfortunately I snapped mine. I cant see why its really required as the plastic pipes that go through the firewall will keep the heater in place anyway.

Slide out heater core.

This method is good if you cant be bothered removing the whole dash but it may cost you a bit more as you'll need to regas your A/C when you've finished.

[Trust33]

You should make a tutorial.Did you take any pics?

[Cubes]

ricsvtr,

All though an R32 I also did my heater core in the same manner.

A/C degassed

Then remove:

glove box

a/c engine bay evap connections

a/c evap box from under the dash (easy)

heater core center plastic clip

4 screws on each heater core water connector and remove connectors

then slide out the heater core.

As it turned out my lower plastic heater core connector was cracked. A new heater box set me back $50 from the wreckers, I only used the core and connectors from it.

My evaporator core was filled with dust and crap (no doubt a jap smoker) + the a/c evap core box also had a dodgy air temp sensor so I replaced the whole lot. I bought a new box from a wrecker for $50, evap core sensors the works.

The new clean unblocked evap core is awesome. So much more air blows out the vents; and with the a/c on its absolutely freezing. Running R12A gas I saw air temps (via diag air temp sensor) at 2degree's on the last warm day that was mid 30's. Refrigerant temps sit ~1-2degrees lower than air.

Prior with the blocked evap core it would hang around 5degree's and push 8degree's on warm days, so a massive difference as to how crispy cold the air feels leaving the vents.

Only once I've seen minus 1degree on a cool night.

[RANDY]

There's no chance that the stepper motor or levers on the heaterbox can be replaced with this same method?... you know... the clicking when you change temps or start the car.