The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 05-22-2012, 09:22 AM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Charging the AC system thru the HP side

I know this has been discussed, but I can not find the reasoning behind it....

Why should the AC system be charged thru the HP side with liquid, i.e. the bottle valve down? The manual only tells us to do this, but not why.

A brand new compressor arrived yesterday :-).

Thanks,

Tapani
Reply With Quote
  #2  
Old 05-22-2012, 10:13 AM
92 SVX 92 SVX is offline
Registered User
 
Join Date: Feb 2010
Location: Jax Florida
Posts: 1,469
Registered SVX
Re: Charging the AC system thru the HP side

I would think you only do it on initial charge, as the compressor would not have anything in it and would need it added first to allow it to turn on.

and only with the a/c system NOT on as you dont want high pressure suddenly pushing the freon back into the can and exploding.
Reply With Quote
  #3  
Old 05-22-2012, 10:45 AM
processengr's Avatar
processengr processengr is offline
Registered User
Subaru Silver Contributor
 
Join Date: Feb 2007
Location: Conn.
Posts: 767
Registered SVX
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by 92 SVX View Post
I would think you only do it on initial charge, as the compressor would not have anything in it and would need it added first to allow it to turn on.

and only with the a/c system NOT on as you dont want high pressure suddenly pushing the freon back into the can and exploding.
The service guide also mentions toggling off compressor with economy switch to avoid shock to compressor every so many seconds.
__________________
Cheers! Gordon
1997 Ebony #308 113k "The Black Diva"SOLD
1992 Black over Liquid Silver 152k SOLD
1992 Ebony 251k 444 SOLD
1999 Silver SLK230 134k SOLD
1997 Green Outback 137k SOLD
2013 Honda Accord I4 SOLD
2015 Subaru Crosstrek 30k
2018 Tesla M3 30k
Reply With Quote
  #4  
Old 05-22-2012, 11:48 AM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

Yep,

http://autoforums.carjunky.com/Autom...YSTEMS_P45460/

So the FSM method is just "pre-flooding" the system + gas charging. Not "liquid charging" as described in the link.

Tapani

Last edited by Tapani; 05-22-2012 at 11:52 AM.
Reply With Quote
  #5  
Old 05-22-2012, 12:12 PM
kwren's Avatar
kwren kwren is offline
Registered User
 
Join Date: Aug 2006
Location: washington state
Posts: 3,499
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by Tapani View Post
I know this has been discussed, but I can not find the reasoning behind it....

Why should the AC system be charged thru the HP side with liquid, i.e. the bottle valve down? The manual only tells us to do this, but not why.

A brand new compressor arrived yesterday :-).

Thanks,

Tapani
charged thru the HP side with liquid is a way to get the correct amount of refrigerant in the system but either way with a new compressor a vacuum has to be pulled on the AC system. To charge the HP side, a vacuum must be pulled in all cases to allow the refrigerant to be sucked in. I personally see no advantage over charging HP over LP. in doing this. I personally charged my SVX on the low side with gas rather than liquid. I am able to do this without even using a pressure gauge. This requires a certain amount of expertize, but for the average person charging through the LP port works better with a gauge to monitor the pressure.

The svx has built in safety components to prevent continuous compressor operation when if the system is overcharged.

Actually liquid refrigerant could possibly gather in the wrong part of the system could possibly cause compressor damage.

I would recommend charging on the LP with gas.,, Of course, ALL "0" ring seals must be replaced with new ones!

Keith
Reply With Quote
  #6  
Old 05-22-2012, 12:26 PM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by kwren View Post
Of course, ALL "0" ring seals must be replaced with new ones!

Keith
Do you know what size they all are? I have new ones for the compressor (R134a unit).

Also, the drier was replaced 8 months ago - should I swap that again? No leaks in the system.

Thanks,

Tapani
Reply With Quote
  #7  
Old 05-22-2012, 01:39 PM
kwren's Avatar
kwren kwren is offline
Registered User
 
Join Date: Aug 2006
Location: washington state
Posts: 3,499
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by Tapani View Post
Do you know what size they all are? I have new ones for the compressor (R134a unit).

Also, the drier was replaced 8 months ago - should I swap that again? No leaks in the system.

Thanks,

Tapani
8 months ago? You are good!!

Keith
Reply With Quote
  #8  
Old 05-25-2012, 11:50 AM
torxxx torxxx is offline
Registered User
 
Join Date: Oct 2009
Location: Alaska
Posts: 126
Registered SVX
Re: Charging the AC system thru the HP side

yah, I would avoid unhooking anything uncessary to the job. Every time you open a joint in the system you increase the chance of a leak at that point.

What they mean about the HP side filling is mainly for oiling the system and getting gas in there so the system isnt running completely dry, causing damage to the compressor.

Any filling from a DYI 134a refill kit should NEVER be hooked to the high side. You will have frozen, shredded hands after the can explodes.

If you've had the system open, you really should put a vacumn on the system to remove water/impurities/air from the system. I skipped this step when I redid my system and I'm regretting it now.

You also mentioned something about the bottle valve down. NEVER turn a 134a can upside down when filling. If you've ever flipped a can of Duster upside down, or spray paint you see what happens. It will freeze the valve, your lines and possible cracking the rubber hose between the valve and the can.
__________________
92 Svx 4.44 swap 198k miles. Toyo Garit KX tires.. my Icetrack car
86 Lifted GL wagon well over 600k miles on the chassis
98 Outback 5 speed 6 inch lift, forester struts/springs 29" tires
Reply With Quote
  #9  
Old 05-25-2012, 12:08 PM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by torxxx View Post
You also mentioned something about the bottle valve down. NEVER turn a 134a can upside down when filling.
See the FSM. It explains the procedure to "flood" the system with liquid R134a prior to actual "charging".

T
Reply With Quote
  #10  
Old 05-25-2012, 02:16 PM
torxxx torxxx is offline
Registered User
 
Join Date: Oct 2009
Location: Alaska
Posts: 126
Registered SVX
Re: Charging the AC system thru the HP side

I realize the fsm might say that but remember that fsm was written 20 years ago. I'm speaking from experience. I worked at a shop recharging AC for a few years so I've done it both with a 5k dollar AC recycling/refilling machine and done it without the machine.

You sound stuck on doing everything the FSM says, but are you even putting a vacuum on the system? Theres no point in following just one step and none of the rest... All thats doing is setting it up for failure and injury.

Let me know how your fingertips are doing after flipping the can
__________________
92 Svx 4.44 swap 198k miles. Toyo Garit KX tires.. my Icetrack car
86 Lifted GL wagon well over 600k miles on the chassis
98 Outback 5 speed 6 inch lift, forester struts/springs 29" tires
Reply With Quote
  #11  
Old 05-25-2012, 08:19 PM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

Quote:
Originally Posted by torxxx View Post
I realize the fsm might say that but remember that fsm was written 20 years ago. You sound stuck on doing everything the FSM says,
I think you missed my question, mate.

Tapani
Reply With Quote
  #12  
Old 05-27-2012, 07:54 AM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

AC is ice cold !

New R134a compressor, new drier, retrofit fittings for the service ports, new O-rings only to the joints I had to open.

The compressor had PAG oil in it, added another 25 grams with the machine. Charged with 500 grams of R134a - the manual calls for 650 grams for a "real" R134a system (same amount incidentally also for an R12 system) - if I am not mistaken retrofits are usually charged with a little bit less if the major components are not changed (condenser mainly). So everything else is stock R12 - let's wait and see the long term operation.

Around 23 C ambient and @1750 rpm the high side is 215 PSI and the low side 24 PSI. Good enough with the R12 expansion valve.

Tapani
Reply With Quote
  #13  
Old 05-27-2012, 10:04 AM
dannmarr's Avatar
dannmarr dannmarr is offline
I work for my SVX
 
Join Date: Jan 2005
Location: Pocono Lake, PA
Posts: 1,647
Registered SVX
Re: Charging the AC system thru the HP side

Congrats! You should do a 'how to' or a youtube video Good luck and enjoy!
__________________
Father of 5 sons and 1 daughter

Subaru SVX for fun
Hyundai Veracruz for the wife.
Susuki SX4 for my older son
Ford Ranger for work
Mercedes Benz Sprinter for vacation trips,
EZ GO Golf cart for driving kids around gated community.
Reply With Quote
  #14  
Old 06-03-2015, 01:20 PM
Tapani Tapani is offline
Registered User
 
Join Date: Feb 2010
Location: Finland
Posts: 815
Registered SVX
Re: Charging the AC system thru the HP side

Update on this.... The system was ok for three years.... Just a while ago the compressor did not turn on anymore. I checked the pressure switch - it was open - too low pressure.

Evacuated and it held vacuum real nice. Recharged with 500g and it's ice cold again.

Cool ��

T
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 12:28 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122