Wachuko

OK, starting the next project for my car. Sent email to validate what was needed to replace the evaporator and change to R134a:

A) New receiver drier, R134a charge port adapters, necessary o-rings for ports you will open, R134a oil, R134a charge and oil record sticker, $100.00

B) New after market copper (yours is aluminum) evaporator with new expansion valve $368.00

C) Check your hoses attached to the compressor, the set two hoses are prone to leakage and wear, $256.00 for the set.

D) Evacuation, charge and test should be done by an competent ac shop with R134a equipment.

E) Added based on comments from rennlisters: You will also need the hot air hoses (more like a flexible aluminum and paper hose). Two (L and R) about US$22.00 from dealer. Believe me there is no way to save them... so have them ready.

I was told gas tank will need to come out for this. I will take photos along the way and start as soon as the parts get here.

Anyone has done this and has suggestions, "while you are there" thoughts, or things to look out for?

springer3

No experience on the 964 AC yet, but I have experience on similar systems. We need great AC in the Southeast, so don't skimp.

It is a "big ticket" item, but if you are going this far, why not also replace the compressor? The compressor shaft seal is prone to leak, and a worn compressor does not develop as much pressure. Also, the compressor oil needs to be drained completely if you have been running R12. You can expect many trouble-free years and ice cold air from a new compressor. Avoid the temptation to use a rebuilt compressor. A new one costs twice as much, but will last 4 times longer and work better (experience with Nippondenso compressors on my 300E). If you do the math, the new compressor is much cheaper in the long run, and you will be cooler.

It is important to flush all pipes, hoses, and heat exchangers remaining in the car. Wear particles and the old oil need to go. In the good old days people used freon to blow the system out. I use "zero residue" brake cleaner to flush the system, and then chase everything left with a procedure the shops can't use. The cleaning procedure works great, and is not dangerous if you take precautions. This will surely bring some gefaws but here it is:

Purchase a brass hardware store fitting to attach an AC service hose to a propane tank (camping type, or the barbeque grill type both work). Your AC loop with have at least two open ends where components are out of the loop. If there is a service fitting in the isolated section, Block one end, and leave one end open. Invert the tank to introduce liquid propane to the system at the nearest service fitting. The liquid will boil its way out with enough turbulence and force to pick up the old oil and any debris. Then block the other end of the system, and flush in the opposite direction. Repeat for any other isolated section of the freon loop. If there is no service fitting in a section, just blow in both directions. Propane physical properties are identical to R22, only flammable. Just make sure you deal with the fire/explosion risk. Risk is managed by keeping ignition sources away, and keeping concentrations below the flammability limits. Propane is flammable over a limited concentration range. Do this in an open space, preferably outdoors. A fan or a breeze will dilute the mix below flammable limits very quickly after the gas exits to the atmosphere. The other hazard is freeze burns if you come into contact with the propane or touch anything chilled by it. Usual disclaimers if you do manage to blow yourself up!

Arjan B.

I informed myself about this project last December. My AC looses pressure, and I suspect a evaporator leak. Max. 1/2 year the gas will hold, after that the system is empty.

Tank has to come out, ventilation system has to come out, lot of work, but is shown on the Porsche Workshop Manuel. May be Randall G. can mail you the instruktions to do this. I can't with my computer, sorry.

I am very interested in the pics you will make. Pleas show us the steps and the hassle you find on your way.

It should be a 8 till 10 hour job the specialist say. A common 964 problem.

Good luck!

Wachuko

I have the worshop manuals (books, not on CD). I will search for the process there. I will do better this time (I know the ignition cable post was not as detailed) in taking photos and describing the process along the way.

Wachuko

Thanks!! I will try not to

911kid

Wachuko,

Where did you buy your aftermarket evaporator and drier? My mechanic says I probably have a leaking evap since he can't detect a leak anywhere else using the dye test. I have to recharge with R12 every 6 to 8 weeks or so. He quoted around $900 for a OEM (I think) evap.

David K.

I have all the A/C parts available from my 93 RS America. The A/C system were removed in perfect working order. You can find the A/C Compressor in Featured Rennlist Classified ad# 1836. Make an offer.

David Katz
rsamerica@comcast.net

Wachuko

Got it at Griffiths ( http://www.griffiths.com/porsche/ ), 1-800-451-7225 (EST)

911kid

Wachuko,

I contacted Griffiths and they have not developed an evaporator to fit in the 964. Are you going to try to retrofit the unit in your car or are you putting it in another model?

Youcef

That is a bit strange because they had quoted me recently for my 964!!

Wachuko

I was to order the parts that day I posted my reply but did not. I wanted to use the car for a few weeks before parking it... I have been a long time without it (see post regarding starter and ignition wires)... you know the feeling, and I started to clean up the garage and install cabinets and tile (doing it myself)... so this is on hold for a month or so...

Anyway, here is a copy of the email I got from them (received on Mon, 23 Feb 2004 5:52:42 AM EST):

"A) New receiver drier, R134a charge port adapters, necessary orings for ports you will open,
R134a oil, R134a charge and oil record sticker, $100.00

B) New after market copper (yours is aluminum) evaporator with new expansion valve $368.00

C) Check your hoses attached to the compressor, the set two hoses are prone to leakage and wear, $256.00 for the set.

D) Evacuation, charge and test should be done by an competent ac shop with R134a equipment.

Griff,
1-800-451-7225 (EST)


Jaime Diaz wrote:

Hi,

I am converting my 1991 Porsche 964 (911) C4 A/C system to use R-134a.

1) Do you have a kit to do so? What is included in the kit and what is the cost?

2) Seems that my evaporator is leaking. Do you sell evaporators for my car and what is the cost?

3) I will need to also change the expansion valve along with the evaporator. What is the cost of this?

4) Any additional parts you know I will also need to get this done? Please list them and provide pricing.

So there, pretty much a conversion and replacement of evaporator and expansion valve and any other additional part required.

Please send me a quote. Thanks!!!

Jaime O. Diaz"

911kid

Wachuko,

I think the mystery is solved. I had asked Griffiths if they sell their high performance (Kuehl) evaporator for the 964 and their response was that no, the Kuehl brand evaporator was not yet available but they are working on it. However after checking they do sell an aftermarket evap. for the 964.
Sorry for the confusion.

Wachuko

Thanks for the follow thru and posting it here. Got me worry there for a minute...

Here is a photo of why I am not working on the evaporator (besides wanting to use the car, and being in bed with one of those nasty 24-36 hours virus...)

I wanted a checkered floor... but at US$0.78 for these porcelain tiles... well... I will leave the checkered floor for when I do my workshop... doing the work myself so it will be awhile before the entire floor is done. Also putting up cabinets and doors to hide the mess, I mean, to cover the shelves.

Before


After (well… more like work-in-progress…)

Wachuko

Parts finally ordered today. Will start taking photos as soon as the parts are in.

Arjan B.

Great, we hope to see a lot of nice photographs. Thanks for sharing with us.