ProCooler for 88 911

[jrosenberger]

Hello Fellow Pelicans, My a/c has been upgraded about 10 years ago. My compressor died the other day. Do I need to replace my ProCooler as well? I was under the impression that it needed to be replaced since the system will be open to the atmosphere. RennAire has gone out of business as far as I know. Where can I source one if I can't use the one I currently removed? I don't know if Griffiths will sell that seperate component, I'm waiting for a reply from them. Any help would be appreciated.
1988 911 Cab. thanks, jimmy

[GH85Carrera]

Most compressors are sold with a receiver/dryer as a pair. Just use a conventional receiver-dryer and forget the pro cooler.

[jrosenberger]

thanks, Glenn for the reply. If I switch to a conventional drier, I'm wondering how to hook it up. The pro cooler has four ports, hence I now have four hoses in my wheel well.one is routed to low pressure compressor, one to front condensor, and two are routed to the evaporator. Doesn't the conventional drier only have two ports? If that's the case, do I now need two driers? and how would the hoses be routed? of is there a drier made with four ports to replace the pro cooler?

[tsuter]

I would not remove the ProCooler unless it is defective/leaks etc. as it performs an important thermodynamic function by reducing cooling capacity loss at the drier ( sweating) that is eliminated by the suction side jacket and keep cold in the system.

Follows is a sketch of my custom built R134a system built in 2008 for my 78SC with turbo tail. I have probably the finest R134a system on this forum blowing mid 30sF at high fan speed with ambients at 95F.



If the ProCooler were to be replaced with a conventional drier, then the #10 suction hose feeding the jacket would not be used and you would need to connect those together in the wheel well (I would not do this) or replace the full #10 line from Compressor to Evaporator. See arrow in drawing that says "normal flow".

The drier itself (inside the ProCooler jacket is serviced by two #6 lines (liquid line) from condenserr to evaporator.

[jrosenberger]

thanks, tsuter..... When the a/c was working I'd never had a car blow as cold as this sytem you've described. My problem was trying to source a procooler.Griffiths suggested switching to a conventional drier. If I do that, I believe the cooling capability will be sacrificed. They have provided me with a link to purchase a new procooler and some "accessories" $360. Do you know of a vendor who would just sell the procooler cannister only? that's really all I need

[tsuter]

Unfortunately, I don't know who sells these anymore as I believe the guy who ran the business is retired. The whole idea of recovering energy from the suction line to retain cold and minimize sweating with an external jacket at the drier is a bit controversial. Particularly on this forum by guys who sell AC stuff.

If yours is good keep it. If not, a conventional drier will only lose a few degrees of efficiency. You make your cold air with condensing capacity through super parallel flow. Hooking little condensers with computer fans in series won't do the job. Frankly if I did not have a turbo tail on my car, I would add a tail just so I could stuff a giant 16 x 30 condenser (480 square inches) up there with pressure switched puller fans. That and a high efficient evaporator are the two best things you can do.

Mine is huge. See pic. It actually goes inside the tail though!

[jrosenberger]

Hey tsuter, my procooler is just old. Probably 10 years. This is my first a/c project. If I pull a vacuum after reinstalling new compressor and one new hose line and the "used " procooler will all the moisture be removed from the procooler making it useable or do I still need to seek a replacement. I think there are mixed reviews over this. Everything I've researched suggests changing out the drier when the system is worked on. I wonder if the same is true with an upgraded system using a procooler or is it good "forever?'
My feeling is to change the procooler while I have everything apart....What are your thoughts? thanks, jimmy

[tsuter]

I use a Robinair 15434. Its a 4CFM pump. I put in new oil and let it run all night. 30-40 minutes won't get the moisture out. Then a few more hours to observe for leaks.
So if you can get a new ProCooler ok but if not just vacuum it like mad with a good pump. That Robinair is good for the house 3-5 ton systems as well with 410A. I use a different set of hoses/gauges and always change to new oil.

[PeteKz]

I've also reused driers by baking them in an oven at 250 degrees, and then doing like tsuter and holding a vacuum for hours to make sure all the moisture is out. Seems to work for me, but I don't have a lot of long-term data on it.

[jrosenberger]

thanks,pete....My easy way out is to source the procooler and reinstall the new one. I'll know later today if I can get a new one....

[GH85Carrera]

If the pro cooler really did much of anything, manufacturers of new cars would use that type of system.



My return line back to the compressor stays cold even on a day in the high 80s. So cold it has ice on it! It helps cool the compressor. I do have the 4 condenser Griffith's system, and a hurricane blower. Two additional condensers in the right rear fender.

I am crazy over the top, belts and suspenders, with glue type of crazy, on my vacuum procedure, and I really think it is part of my systems great performance. It is truly impossible to have "too good" of a vacuum. More vacuum is always better 100% of the time, always, no debate.

I get the system tight, pull a vacuum for 10 minutes, down to a few hundred microns. The I pressurize with dry nitrogen to 100 to 150 PSI with dry nitrogen, and I let that sit overnight to test for leaks. 150 PSI will show a leak way faster than a vacuum. I hose down all the connections I can see with soapy water to look for bubbles.

In the morning, I pull another vacuum, this time for 30 minutes until I am down into the low hundreds in microns.

Another pressurization with nitrogen, and then a long three+ hour run on the dual stage vacuum pump with fresh oil in the compressor. I get to the double digit level in microns, and then then and only then, add refrigerant.



When the little weenie side vent in my 85 911 will blow ice cold air with the blower in hurricane mode, and get me freezing, on a 30 minute test drive, I know the system is at 100%.

I honestly believe the 911 is unique in the AC world with a ton of hoses, and four compressors, from under the front bumper to the engine deck-lid. Moisture can hide in there and turn to ice and a vacuum alone will not get it to subliminate and go away. The dry nitrogen under pressure and the vacuum will make it all go away. Just a little moisture is bad pookie for out systems.

And it is also vital to have all new barrier hoses. The OEM hoses will just leak as they are designed to do. I can go for years and not touch the system.



This is all just my opinion, I am not an expert. But I drove to Key West in July 90+ degrees 90% humidity, and I could not run the AC at full cold because I got cold, and that was with my brother in the car with me.



And for those people reading and wondering about microns, it is the only logical way to talk about a level of vacuum. 200 microns is 0.0038673555742632 PSI. 100 microns is 0.0019336777871316 PSI Your dial gauge can't display that change, you need a micron gauge.

[jrosenberger]

The procooler is baking as we speak....

[Jonny H]

Originally Posted by GH85Carrera

If the pro cooler really did much of anything, manufacturers of new cars would use that type of system.

Er, they do. Since the introduction of R1234yf, to improve efficiency, modern cars use a an IHX (internal heat exchanger) which uses the cooler suction line to cool the high pressure line prior to entering the evaporator. Procooler is essentially an IHX.

(I have no affiliation with whoever makes/made Procooler)

[tsuter]

Uhh..... don't let the secrets out....been specifically looking at this technology to replace the two lines from the back of the car to the drier and evaporator with a single jacketed line with four fittings...aka an IHX. That way the drier is not captive in the ProCooler method but the efficiency is not lost. A Chinese research paper indicted 4-5F degrees pick up at the vents at idle
See Kia Soul part here:

https://www.ebay.com/itm/204049214733?epid=243721578&hash=item2f8247ed0d:g:GOMAAOSwqBxjJL-e&amdata=enc%3AAQAIAAAA0Lqq6jnl%2F8E8TZftc6Uh4KWIKfg sE%2BVwrfyt%2BvcPdUDGzrB9SgnIY%2Fx7MSL2wkz6sYXNoZt abHQFo%2BnWOFPLRXdI7SF22KRQi8nOpDS9cSvolEor2HvIWKQ M8kKfKx%2BzY77Ti51MLYL6J0eX8EQ72JQ6jjf6tLI4C94JHGL S7VO%2BrYb%2FCU8y5FdR1JGnvk8gWxsCDBBNXNleSMbcqXaN5 q3%2FXDAVbUGQrQqoc1z0vZRqXt%2FEOP8uCyuVcZHoL1A1QS8 wYtBHKpMakpKnjWg0fIY%3D%7Ctkp%3ABFBMoNi31pFi

[jrosenberger]

Half way there..... Old compressor had no oil in it. I installed procooler and hose lines. Hooked up new compressor and electric components. Waiting for one line from griffiths tomorrow. Then it's show time.....

[jrosenberger]

thank you all for your input. car is back together. thermometer reads 50degrees. was hoping for the forties but all things considered, I'm happy and I'm Cool again.....jimmy

[tsuter]

So when you charge you charge by pressure. Don't go by ounces
What were your pressures? Low side and High side? The Gauge shows you the R134a pressure that corresponds to the target temperature
Also make sure the decklid is closed when charging. Not up. Its a gravity thing. The #6 liquid line on the condenser is on the lower side when the deck is closed.
Engine should be at operating temp and use a block of wood or something to hold the RPMs at 2000 when charging.
Adding refrigerant, it has to stabilize sometimes rather slowly over several minutes.

[jrosenberger]

thanks tsuter. i returned the manifold this morning. i did go by ounces. thanks for the education....jimmy

[kamaro]

Based on my experience with these cars in extreme middle east summer (110*F for several weeks on a row), the most important part in your A/C is your condenser, get the largest parallel flow condenser you can fit in your car. I had a Classic Auto Air A/C kit in my car which uses a single parallel flow condenser in the rear, and the vents were blowing 30*F cold stream of air all day long. In my '87 I'm still using the stock A/C with R12 and I can describe it as marginal at best and yet it uses dual serpentine style condensers. Forget about the Pro-Cooler thing, I have it and never bothered to install it as it will just add complexity to an already complex system.