Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 924/944/968 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
All Spooled Up
 
Join Date: May 2009
Location: Between NE and Central PA
Posts: 2,516
A/C retro/upgrade? After you cut through all the BS, It can be as simple as this!

Forget all of the damn "conversion" kits, and problems accessing the LSP. This is all you need to do (for a system that is out, or too low on, refrigerant or oil charge, but is in otherwise good condition).

1. Get 3 cans of R-134a and 1 can of ester (NOT PAG) oil, and place them in a bowl with HOT, running water in the sink for 5 to 10 minutes.

2. At the easily accessible HSP, bleed out any residual charge, allowing as much of the oil to come out as possible.

3. Make sure the engine is at it's coldest (probably early morning, before being started). DO NOT START IT now, or UNTIL AFTER the last can of R-134a is emptied, and the HOSE IS REMOVED! If the engine starts and the A/C compressor comes on while the hose is connected to the high side port (HSP), the can (or hose) will probably burst in you face - consider yourself warned!

4. Starting with the ester oil charge, take 1 can at a time out of the hot water bath, shake it (especially important for the oil) and install the valve to it while walking to the car - which already has the hood up, the cap removed and quick-connect adpater intalled on the HSP. Connect the hose to the HSP (you can clear some air out of the hose before you attach it by opening the valve on the can, while in an "upright" position, until some gas is heard escaping). While keeping the can in an "upside down" position, with the bottom of the can as high as possible, open the can valve completely and allow all (or nearly all, if you can't seem to get it all) of the liquid to transfer out of the can. Problems getting all of the liquid to transfer can arise if the engine is not at a cool enough temp - or if the cans are not hot enough when the refrigerant is being transferred. Disconnect quick- connect valve valve from HSP and unscrew from can.

5. Repeat step 4 for rest of cans. Remove the screw-on quick-connect adapter from the HSP and replace it with the screw-on cap. Start/drive car and enjoy your cold A/C.
__________________
>gray 89 951S - K27/8, MAF, 3" intake, 3" exhaust w/separate waste pipe, 55# inj, late cam; >red 87 924S - chip, K&N, punched-out cat&muffler >black 80 924 - (sold) >maroon 77 924 - auto (sold)
Old 06-21-2009, 02:04 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
your average wrencher...
 
Join Date: Oct 2007
Location: Bedford, PA
Posts: 1,365
Garage
dude, your crazy............but that may actually work.




by the way, where in pa are you?
__________________
1986 951 Garrett turbo, Rogue Tuned.
1987 944S chipped, konis, rollbar (traded)
1979 924 total rebuild and blueprinted (sold)
1988 XJ 5in lift,long arms, 4.6 stroker, ax-15 w/ 35s
1995.5 Audi S6 Full RS2 bolt-ons, EFI tuned.
Old 06-21-2009, 04:22 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered User
 
Razorback1980's Avatar
 
Join Date: Nov 2005
Location: Houston, Texas
Posts: 2,944
Garage
Send a message via AIM to Razorback1980
I wouldn't follow any of this advice. It takes a lot more than this to convert A/C to R134. Never and I do mean Never connect a can to the high side. This may or may NOT be safe if the system hasn't been charged up. Theoretically, the pressure should be the same on both sides if it's never been started but you have guarantee without the use of gauges and that's dangerous. You also shouldn't mix oil. The system should be cleaned and vacuumed before filling. There are several threads on how to do this properly...those are the ones that should be followed.
__________________
Tom

1990 944S2 Cabriolet
2002 Chevy Silverado 2500HD
2003 Maroon Ford F350 dually
Old 06-21-2009, 05:34 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Just thinking out loud
 
mattdavis11's Avatar
 
Join Date: Nov 2001
Location: Close by
Posts: 5,298
It's a recipe for disaster. Don't do it.
__________________
83 944
91 FJ80
84 Ram Charger
Old 06-21-2009, 06:25 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jul 2008
Location: Colorado Springs, CO
Posts: 91
I'm not sure if anyone else has noticed this, but you guys are saying this is very bad advice and his name is wild man hahaha
__________________
1984 944 NA

A wise man once said, "Speed cannot be complimented with control, and that control is achievable only without speed." That man obviously has never driven a Porsche
Old 06-21-2009, 06:46 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered User
 
TexasBlake's Avatar
 
Join Date: Jan 2009
Location: Denver, Colorado
Posts: 220
Garage
Sure, you could do it. But that does not mean it's meant to be done. I wonder how this method gets all the moisture out of the system that was introduced by opening the HSP.



While you are at it, you could also change your oil by drilling a hole in the oil pan and then covering up the hole with JB Weld. Both accomplish the task.

After you're done, you can go buy some 3" flex pipe and hose clamp them to your cross over pipe. Why the hell would you spend money on 3" exhaust when flex pipe is so cheap!

Last edited by TexasBlake; 06-21-2009 at 07:31 PM..
Old 06-21-2009, 07:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered User
 
Join Date: Jan 2009
Location: Missouri
Posts: 199
I'm sure the EPA is considerably interested in his accomplishments. I'll make sure I never buy a car you have touched.
__________________
'83 944 N/A
'88 Ford F-150 4WD - Does Everything
'99 300M - Daily Driver, headlights just polished!
'85 34' ITASCA MotorHome, built-in blender baby!
'89 Supra - Black - Future 400hp NA sleeper.
Old 06-21-2009, 08:28 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Just thinking out loud
 
mattdavis11's Avatar
 
Join Date: Nov 2001
Location: Close by
Posts: 5,298
Some of what was provided isn't all that bad, but for the novice, don't go there. I've charged from the high side, but only after I've sucked in oil on the high side then chased it with a touch of freon to clear the lines. The system was maybe at 45psi. That won't blow your hand off, but you damn well better know what you are doing. I'm sure everyone knows how to clear gauges when the system is functioning, but that's probably another thread.
__________________
83 944
91 FJ80
84 Ram Charger
Old 06-21-2009, 10:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered User
 
Join Date: Mar 2004
Location: Tacoma, WA
Posts: 748
So I'm curious, did it work. Where did all the non-condensibles go? Did you replace the drier? Did you leak test first?
Old 06-22-2009, 06:39 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
All Spooled Up
 
Join Date: May 2009
Location: Between NE and Central PA
Posts: 2,516
Quote:
Originally Posted by WaA420 View Post
So I'm curious, did it work. Where did all the non-condensibles go? Did you replace the drier? Did you leak test first?
Of course it worked, or I would not have passed it on. But there are dangers involved that you must be astutely aware of. I also use R-290, which adds another layer to the "danger" aspect. Like the guy said, I AM the wild man, for Christ's sake! It's a tough act to follow, though. Once you acquire a name like that, you've got to live up to it, or else everyone will dis you.

Seriously though, I've used 290 in all of my vehicles since 96 without any issues (such as a fire). But this is the first car that I have come across where I could not find a low side port (I never got "down and dirty" enough with it to remove the underpanel(s), loosen the belt tensioner, remove the belt, and move the compressor over to where you can see/access the low side port). So I came to believe it did not have one. That led me to assume it was meant to be charged from the high side, using equipment that probably only the dealer had. With porsche, it's not hard to fall victim to that logic! I feel I am pretty good at subverting measures people take to prevent you from doing something (don't forget, i have a name to live up to). So this is the logic I came up with to charge from the high-side without having to buy expensive high-side charging equipment (I NEED my A/C, and so goes the saying that necessity is the mother of invention):

There is only a difference in pressure between the high side and low side when the compressor is running, and a couple of minutes, lets say 20, to be safe, thereafter. Otherwise, the pressure is equal everywhere in the system. With R-290 (R-134a is a little higher - I don't know the exact figures), static pressure is around 65psi at 32 degrees (F), and about double that (130psi) at 100 degrees. When running, high side should be in the neighborhood of 300psi, and with proper amount of charge, low side should be 30-35psi. Knowing that, it's easy to see how it will flow easily and quickly from the can into the low side port. It is also easy to see from this how the direction of flow will reverse if connected to the high side, bursting the can. Flow ALWAYS occurs FROM higher pressure TO lower pressure - that should be obvious to anyone who is mechanically inclined. To put the charge into the high side port directly from a can, it MUST (can't stress that enough) be done statically, meaning that the compressor must not be allowed to turn on while the hose & can are attached! The issue is getting the refrigerant to flow out of the can and into the system, when you don't have the suction side of the compressor "drawing" it in. So you must make use of temperature as the method to create a pressure differential, and therefore, flow, to get the refrigerant out of the can, and into the system. That is why the system must be as cold as possible (winter time would be the best, but who needs A/C then?), and the cans of refrigerant must be as hot, better say warm, as possible, with an upper limit of no more than 140 degrees. Since adding each can will warm up the system a little more, the last of the last can will flow the slowest, and be the hardest to completely transfer. It would probably be best to do each can, starting with the ester oil (which is compatible with R-12 oil), and one can of r-134a), and do each of the other 2 on successive cold mornings to get the most in to the system. If pressure was bled out of the system first, it should have a full charge, even is a little bit of refrigerant was lost from each can.

As for leaks, I used oil that had leak detector (dye) in it - came up clean, and still is, as far as I can see. But remember, all automotive systems will gradually loose refrigerant over the years, because they are not hermetically sealed (the compressor shaft seal is not a 100% perfect seal). As for non-condensables, I assume you mean gasses such as nitrogen and oxygen. If there was any in the system previously, it should have been removed during the bleed-out step. If it had some pressure in it beforehand, there were probably no non-condensables in it, anyways. And to keep from introducing any yourself, purge the hose by opening the can valve a little bit ( you should hear it hiss) right before attaching the quick connector to the HSP. I have not found the need to replace the drier, or any other component. But if the system is not in ideal condition, or had a big leak, or component replaced, which caused the system to be open to the atmosphere, you should definitely replace the drier and place the system under vacuum for a few hours prior to charging it.
__________________
>gray 89 951S - K27/8, MAF, 3" intake, 3" exhaust w/separate waste pipe, 55# inj, late cam; >red 87 924S - chip, K&N, punched-out cat&muffler >black 80 924 - (sold) >maroon 77 924 - auto (sold)
Old 06-23-2009, 04:59 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #10 (permalink)
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 


All times are GMT -8. The time now is 10:49 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.