Refurbishing a Clardy A/C evaporator

[Themis]

Step 1. Disassemble the box

In my case, the motor was dead, the valve was stuck, and the fan switch / thermostat was rusty. So, only the box sides and the core could be reused. Checking the core is a good idea, to make sure it does not leak. Make sure the threads of the core are in good shape.

 

 

Step 2. New insulation around core

Many materials can be used for this purpose, I went with this guy. I’ve used it before for refurbishing my heater box with good results.

I cut several pieces and covered the core as seen in the photos. Dry fitted the core in the box, to make sure of a snug fit.

 

 

Step 3. Filter at output

My box had a disintegrated filter at the output, which resulted in bits and dust being blown at the occupants whenever it was turned on. I used a vent filter, cut to size and secured on the core with those plastic-covered wires.

 

 

Step 4. Screw back the box

 

Used stainless steel screws secured with threadlocker. Do not forget the resistor block (secured with screws from the inside of the box. For the two brackets on the top of the evaporator, I used rivets to secure them on the box.

 

 

Step 5. New evaporator expansion valve

The correct type is EX-9404C, which I got from UAC. Thread it carefully to the core inlet / outlet. From the radiator shop that cleaned and tested the A/C, I got for free a strip of sticky tar stripe (I do not know its technical name). This is used to insulate the area between the expansion valve and the box.

 

 

Step 6. Installing a new blower motor

The correct blower motor is the DCM D-001-435. At the time I bought it, the best deal I could find online was at Trucker AC (truckerac.com). It was $64.00, plus $24.00 shipping.

In the original Clardy assembly, the motor is held in its cage with two metal parts: a circular flange bracket, and a tripod clamp. These are really cheaply made, thin and flexy. By the time I removed the rust and painted mine with POR-15, they were even thinner and flexier. I actually assembled the box with this setup, but I was dissatisfied with the end result so I went back and removed the bracket altogether.

Luckily, a much beefier attachment bracket is available from the manufacturer of the motor’s housing and fan. The manufacturer is American Plasti-Plate in Tyler, TX. Previous information on the forum indicated that this company does not sell parts retail; however, I was not able to find the parts I was looking for at any other dealer / supplier. I called American Plasti-Plate directly (903-8947281) and spoke with Tony (or Donny?). He was extremely helpful, and he put in the mail next day the parts I needed!

The parts are:

Blower housing BH-4500 with flange

ABS blower wheel with clip #28-01716 (this part is also available at ACkits.com)

Motor Mount MM 4.5. This motor mount comes with rubber grommets where it attaches at the motor housing

 

 

Step 7. Final assembly

The motor housing was riveted on the box, for strength. Then, the motor mount was screwed on the housing. The wheel fan is then attached to the motor shaft and secured with a clip. Finally, the fan housing plastic vent circular piece is screwed on the wheel side. For this last piece, I do not recall if it was part of the housing, or if the good guy at American Plasti-Plate included it for free.

It’s a good idea to power the motor at this point, to make sure the wheel doesn’t rub anywhere.

 

 

Step 7. Sealing the box

 Seal all around the seam of the box with silicone. I used VersaChem Mega Black RTV silicone

 

Step 8. Front panel controls

 

For the front panel, I bought a new switch and thermostat, along with their knobs. It is surprising these parts are still made (and very cheap). They were bought from Nostalgic AC Parts (nostalgicac.com). The prices below are circa 2017.

- Part# 119-9908 Rotary Blower Fan Switch $9.99

- Part# 119-9921-18 Rotary Thermostat 18 Inch Capillary Probe $19.99

- Part# 1011 Blower Switch Knob $3.99

Part# 1012 Rotary Thermostat Knob $3.99

 

 

 

 

Edited April 5, 2019 by Themis

[jgerock]

Excellent write up!  Should be an article.  Thanks for your contribution.

[Simeon]

5 hours ago, jgerock said:

Excellent write up!  Should be an article.  Thanks for your contribution.

 

Yes it should. What happened to the ‘promote to article’ button?

[Conserv]

This should absolutely be an article! This is amazingly informative, complete with replacement part numbers and vendors.

 

Well done and detailed description of the overhaul process. I especially like the upgrade to the blower motor mount!  You don’t mention whether you will be using R12 or R134a: my A/C guy believes that expansion valves — despite claims for universal application — are suited for R12 or R134a, but not both.

 

The two-digit prefix to the unit’s serial number represents the year of manufacture, so yours, a 1976 model, is quite early — the Clardy system was introduced in 1975.

 

Thanks and bravo!

 

Regards,

 

Steve

 

 

 

Edited April 5, 2019 by Conserv

[\\\Mink]

I wish this was available when I did mine.  I spent so much time searching for the right parts and now here they all are in one place.  Well done.

[Einspritz]

3 hours ago, Conserv said:

my A/C guy believes that expansion valves — although many claim to be universal — are suited for R12 or R134a.

 

They are specific to the refrigerant regardless of what anyone tells you.

 

In particular, the pintle (valve) is different and more importantly the refrigerant in the bulb is specific to the system for opening and closing the valve.

 

You can "mix and match" of course, but it won't work as the system was designed.

[\\\Mink]

I ended up with a GPD 3411301 expansion valve for my Clardy.  The box was labelled R134a but don't know how much stock I put in that.  It seems to cool very well but also hasn't been particularly warm yet either.

[Conserv]

32 minutes ago, Einspritz said:

 

They are specific to the refrigerant regardless of what anyone tells you.

 

In particular, the pintle (valve) is different and more importantly the refrigerant in the bulb is specific to the system for opening and closing the valve.

 

You can "mix and match" of course, but it won't work as the system was designed.

 

Thanks, Matt, for explaining technically and clarifying my language, which I now realize was certainly not clear: my “R12 or R134a” should have been followed by “but not both.” Now fixed in the original post.

 

Best regards,

 

Steve

 

Edited April 5, 2019 by Conserv

[Conserv]

15 minutes ago, \\\Mink said:

I ended up with a GPD 3411301 expansion valve for my Clardy.  The box was labelled R134a but don't know how much stock I put in that.  It seems to cool very well but also hasn't been particularly warm yet either.

 

So you’re saying that you’re using R134a, and a GPD 3411301 expansion valve works for your system?

 

Although the I.C.E. AIR system — a modern knock-off of the Clardy system — was designed with R134a in mind, I suspect that all true Clardy systems (1975 to approximately 1990) were designed as R12 systems. Many Clardy systems have been converted to R134a over the years, but I’d bet many of those conversions did not include a new expansion valve. They should have.

 

I still run R12 in my ‘76’s original ‘76 Clardy. And it works as well as ever...which is to say “It’s ‘02 A/C with the air distribution shortcomings inherent in all of these ‘02 systems!”

 

Regards,

 

Steve

 

Edited April 5, 2019 by Conserv

[\\\Mink]

8 minutes ago, Conserv said:

 

So you’re saying that you’re using R134a, and a GPD 3411301 expansion valve works for your system?

 

 

Correct.  I have only used it a couple of times since installing, and only in mild temps, but it gets ice cold instantly and gets so cold that it needs to cycle the compressor even on its coldest setting.  I will of course need to report back on its performance at 90 degrees!

 

[Einspritz]

You "can" run R134a in the system but the refrigerant has ~80% of the cooling capacity of R12.

 

The compressor should be fine with either, and the evaporator "OK".

 

You should however, replace the EXV and increase the condenser capacity by "about" the same 20%, or greater if you can. This can be achieved by a larger cooling capacity in either larger surface area of the tubes and fins (e.g. more and smaller tubes) or serpentine or parallel flow design.

 

The action of a supplemental fan and / or driving on the highway at speed will condense better than not. That is why many say that R134a works just fine at elevated speeds but is poor around town.

 

A quick, but not definitive check would be to measure the inlet and outlet temperatures of the condenser, and that differential is what you will get in reduction of temperature between ambient and what comes out of the cold vents.

 

In my view, as with on the E30 systems, it is better and cheaper to source R12 and keep the system as installed rather than try to shoehorn a larger condenser in with unknown cooling capacity.

 

As an aside, you can check the operation of the EXV by spraying the bulb with a can of "duster" held upside down and then blowing through the orifice. If you can, the valve will operate. If it has a lot of black particulates inside, the likelihood is that they are "gumming" up the works.

 

In my E30 cars, I stayed with R12 because it just works better.

[Themis]

Thanks for the positive feedback all. Regarding the expansion valve, I have seen the I.C.E air system, and that is the exact valve their system uses, set up for R134a

[BarrettN]

Fantastic info - but being put off a little by the $24 shipping cost for the blower motor, I did some digging - the DCM PN cross-references to a uacparts PN #BM 4350. And they source the motor from DCM.That's all great - but uacparts doesn't sell to the public. However, pitstopauto.com carries uacparts, and they do sell retail. Searching on their web site didn't give me a hit with either the uacparts or the DCM PN, but I chatted with them, they confirmed they carry it, have 70+ in stock - and the price is $57 with shipping included (in the US)   .

 

 

Has anyone ever gotten anywhere on finding a blower motor that produces a higher airflow? I remember someone was looking into this but I didn't ever see anything more. Then again, it sounds like the condenser heat capacity is the limiting factor - I'm inferring that from the comments about needing to suck small dogs off the pavement with your aux fan in order to get decent cooling. So does anyone know if that is that the weakest link, or if there is something to be gained by improving on the under dash components?

Edited April 5, 2019 by BarrettN

[Themis]

Good work Barrett! Obviously, I didn't research carefully enough - I remember the high shipping cost made me procrastinate in this (hard to swallow), but in the end I bit the bullet and ordered it, having found no cheaper alternative

[Einspritz]

2 hours ago, BarrettN said:

I'm inferring that from the comments about needing to suck small dogs off the pavement with your aux fan in order to get decent cooling. So does anyone know if that is that the weakest link, or if there is something to be gained by improving on the under dash components?

 

You can do / check a few more things.

 

Which fan do you have? 5-Blade "Tropical" version?

Can you or do you have a fan shroud used on late model cars?

 

The rest (interior) is what it is, a 40 year old design that works reasonably well once you have enough time to get the interior cool and keep it that way........and in case you don't know, BMWs of that era, particularly the E12s (we had one) were notorious for having lackluster A/C (it was). The rumor was that BMW NA took a few German engineers for a ride  in Texas with the existing systems which were subsequently redesigned.......