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Heater matrix problem

5K views 17 replies 7 participants last post by  rooony 
#1 ·
After rebuilding the heater box with new fan and matrix for my RHD GTV 2000, i come round to plumbing the cooling system in and noticed the metal pipe from heater matrix core is way out of line with grommet and bulkhead hole. The long straight heater hose will not fit through grommet and onto the pipe.

Both rubber hoses to valve and matrix are not kinked sideways just metal pipe is too high and valve side fits perfectly inline to the bulkhead hole.



The problem is with the metal pipe from heater matrix


The metal pipe is approx 35mm too far up for the straight rubber hose to fit



Any ideas?
 
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#2 ·
Have you compared the orientation of the metal pipe on your new matrix with that on the original?

I am going through the same process on my 75 GT Junior. I had similar problems with the new matrix - bought from Classic Alfa. I suspect that the pipe is at a different angle. When I got my car the rusty old matrix wasn't connected and having got the new matrix plumbed in, I didn't want to remove it for a side by side comparison.

I connected up the matrix with the top section of the heater box only loosely bolted to the bulkhead, then I just about managed to fit the bottom section of the heater box - with the 5 metal spring clips - and then bolted it up tight to the bulkhead. I suspect that the metal pipe is under unnecessary stress though due to the poor alignment :-(

I had issues with the blower fan and motor too - but that's another story.

If the pipe alignment is massively out, can you return the matrix for replacement? perhaps with a photographic comparison.
 
#3 ·
After some digging I can only conclude i have the correct late heater matrix from classic alfa however it is different to original which maybe specific to late gtv 2000. I say this because old matrix doesn't lay flat on the table whereas new one does.

I won't do as you have Malcolm high chance matrix will crack its way too out of line for that 5mm maybe but not 35mm. The simplest solution i can think of cut the new matrix pipe off and bend up new pipe with bead rolled on the end and braze it back onto matrix.
 
#4 · (Edited)
Interesting. If it is different to the one that's available, then yes, it makes sense to have to modify it to fit. If the pipe has just been brazed on at the wrong angle, then perhaps CA have others which are more suitable - or a general quality problem

This is the alignment problem that I faced, when I came to fitting the lower part of the heater box to the upper part bolted to the bulkhead
 

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#7 ·
malcolm1 yes its the same problem i tried to reassemble as you have its not acceptable in anyway i rather bypass the matrix entirely than risk rusting out my new floors. Coincidentally i looked at aircon upgrades which has same problem.

Classic Alfa only has 2 types an early and late which is same for all suppliers i searched.

Im confident for last years of production there is significant undocumented differences in number of parts, like bulkhead steering grommet i had to make my own because certain parts are substantially different in 1975/1976.
 
#11 ·
I have a good heater matrix from a 71 Spider. My heater box looks identical to your picture. Let me know what to measure, and if it fits, it's yours very cheap. Of course, I'll be glad to shoot more photos too.

View attachment 1138721
Thank you very kind offer your heater matrix is same as my new one the outlet pipe isn't angled enough down by approx 45 degrees.
 
#10 ·
I can post an image of what I assume is the original (rusted out) one from my 1975 Junior. I assume that the angle of the outlet pipe is correct for these later cars - I didn't notice if it did point directly at the grommit, when I removed it. The PO had bypassed the matrix and removed the heater hoses, so they weren't in place when I got it.

I think the angle on the slightly earlier ones is too flat - which causes the misalignment.

I will contact Classic Alfa and see what they say
 
#13 ·
Here's a photo I took during my tear down phase and the elbow clearly did not line up exactly with the hole in the firewall. It looks like the heater hose needs to bend down as it penetrates the firewall. If this is hard to achieve....perhaps the new heater hose that you are using is much more rigid that the original hose?
 

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#14 ·
Also, comparing the new heater core that I got from CA...the elbow points down only about .100" more than an original (early style heater).

Early style heater core..

Material property Black-and-white Room Architecture Photography


reproduction heater core (from CA)...

Cylinder Metal


p.s. if you zoom in on the bead formed on the outlet....you will note several cracks on the surface of the bead itself. Clearly reproducers often times more than not just don't care or just don't have the engineering expertise to get things right.....like the original.

..
 
#16 ·
I am in the process of swapping my dash on a 71 spider and have decided to give the heater a quick refurb.. i.e. a new Valve and a new matrix.... Could any one tell me how you could test the heater motor whilst it is out the car? would it run straight of a 12v battery?

Appreciate any advice..
 

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#17 ·
Does the fan spin freely by hand?

Black wire to ground
12v to both the other terminals for fast fan (or just the terminal not connected to the power resistor on the motor - yellow on my original motor).
12v to the terminal connected to the power resistor on the motor, for slow fan - red on my original motor

Good luck, hopefully yours is not seized or burnt out like mine (75 junior)

Also worth noting the position of the arm/cables on the heater control valve (in the cold and hot positions) - to make it easier to set-up the new valve
 

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