R129 heater matrix interchangeability (that's a big word!)

[Alan67]

Hi there,

I'm in the process of getting things in place for a local garage to carry out a heater matrix change on my 1992 500SL. I'm getting a new matrix made from scratch by a local specialist, as they're no longer available from MB. I know, because I ordered one, paid my money, then got it all refunded 2 days later!
So anyway, to reduce the amount of time that the car is sitting taking up floor space at the garage, I would like to get hold of a used matrix for the guy to use as a pattern part, so that the new matrix is ready to go in as soon as the old one is stripped out.

Problem is, I'm aware that the heater boxes themselves come in several permutations, depending on MY, engine type, size, aircon etc. However, what about the actual matrix/heat exchanger? I personally can't see any reason for MB to use a different matrix for each engine size, year etc etc....., but you guys might know different.
I've been given a part number by MB for the NLA heater box, which apparently is the only one guaranteed to fit my car, but they can't (or won't) say if any R129 matrix will fit into my box...so to speak!

By the way, the reason I need a matrix swap is a very long, drawn out saga that's been a thing since 2015.
It's fooked, and that's the end of it!

Cheers guys

 

[star]

Yes there is at least two types that I know of, not sure if there are also different for lhd. I have one apart at the moment. Good luck getting one made, I’m sure it can be done but with a lot of faffing. The heater matrix has plastic end caps, at one end the pipe work bolts to it with O rings for seals.

 

[LostKiwi]

Looking at the parts catalogue there are 2 different heater matrixes each of which has a later substitution so 4 part numbers in all.

 

[grahamcol]

Hi and welcome. The SL shop may be able to help.

 

[Alan67]

Yes there is at least two types that I know of, not sure if there are also different for lhd. I have one apart at the moment. Good luck getting one made, I’m sure it can be done but with a lot of faffing. The heater matrix has plastic end caps, at one end the pipe work bolts to it with O rings for seals.

Hi,

Since posting this, I've heard back from the technical team at the MB Club. They're saying the matrix I have in my car is part 'A 002 835 65 01'. Apparently, there are non AC, manual AC and fully automatic AC versions. I have the manual AC apparently. Didn't even think I had AC looking at my heater controls, but they're saying it's listed as such on the Data Card for my car.

The guy making the matrix replaces any plastic parts with aluminium.

I've managed to source the 'O' rings, and I believe the clamp is reusable. I'm going to see the guy this afternoon with some (rather vague!) photos I've found online. I don't suppose you could take a photo or two of the one you're working on could you?

 

[Alan67]

Looking at the parts catalogue there are 2 different heater matrixes each of which has a later substitution so 4 part numbers in all.

Yeah, I've now got a part number of A 002 835 65 01 but finding one is the issue. Everybody is out of stock. Just need to continue searching...

 

[Alan67]

Hi and welcome. The SL shop may be able to help.

Hi and thanks.

They don't have the correct one listed on their catalogue. Same with R129.co but at least I know the number I need now, and that there are 3 different ones that were made. I suppose 6 if you count LHD!

 

[00slk]

LHD and RHD heater matrix's were different in most of the '70's to 90's basically the inlet and outlet pipes being on the left or right as the case may be.
I have done some right from left hand drive conversions and have also found that the air cleaner housing can be difference on AC and non AC cars, not too mention the steering wheels having different bore sizes which was odd.

 

[star]

Not sure which one this is, we were supplied the incorrect one but you can see the plastic ends.

 

[Alan67]

Not sure which one this is, we were supplied the incorrect one but you can see the plastic ends. View attachment 75450 View attachment 75449 View attachment 75450 View attachment 75450 View attachment 75449

Great photos, thanks. Much better than I could find anywhere online!

So I've been to see the guy who's making up a new matrix. He does radiators, oil coolers, heater matrix etc, made up from aluminium or stainless steel. He's explained that he buys in the matrix core, to the dimensions in the part number diagram of 222mm x 207mm x 40mm, then makes up the tops and bottoms to suit the application. He will not be reusing the plastic ends, but making aluminium replacements instead and will weld short protruding pipes onto the new tank (where the holes are in your pictures) ready to take short rubber hose adaptors, which will then attach to the new aluminium pipes that he will also manufacture, using the existing ones from my car as a pattern. He's said that as soon as my car's been stripped down, and he gets the old bits in his hands, it will take about 5 hours to get the new matrix and pipes made up. They can then be delivered back to the garage and put back into the car, and everything put back together again.

Hopefully starting to get somewhere now. Will be speaking with the garage middle of next week to arrange a date to begin the strip down. Hopefully around the start of April if all goes to plan.

 

[LostKiwi]

Great photos, thanks. Much better than I could find anywhere online!

So I've been to see the guy who's making up a new matrix. He does radiators, oil coolers, heater matrix etc, made up from aluminium or stainless steel. He's explained that he buys in the matrix core, to the dimensions in the part number diagram of 222mm x 207mm x 40mm, then makes up the tops and bottoms to suit the application. He will not be reusing the plastic ends, but making aluminium replacements instead and will weld short protruding pipes onto the new tank (where the holes are in your pictures) ready to take short rubber hose adaptors, which will then attach to the new aluminium pipes that he will also manufacture, using the existing ones from my car as a pattern. He's said that as soon as my car's been stripped down, and he gets the old bits in his hands, it will take about 5 hours to get the new matrix and pipes made up. They can then be delivered back to the garage and put back into the car, and everything put back together again.

Hopefully starting to get somewhere now. Will be speaking with the garage middle of next week to arrange a date to begin the strip down. Hopefully around the start of April if all goes to plan.

I'm sure @star will be very interested to hear how you get on.

 

[Alan67]

I'm sure @star will be very interested to hear how you get on.

I'm thinking quite a few people might be interested. Sooner or later.

Once everything gets moving, I'll try to get some photos.

 

[LostKiwi]

Fortunately my 129 heater core is ok at the moment....but I'm definitely watching with interest!